Notice: Hayes Microcomputer Products, Inc. reserves the right to make
improvements to the product described in this manual at any time and
without notice.

Hayes, the Hayes icon, the Hayes logo, the Hayes '302 Escape Sequence
Patent icon, V-series, Smartmodem, Smartcom, OPTIMA and ACCURA are
trademarks of Hayes Microcomputer Products, Inc. V.FC is a trademarks of
Rockwell International Corporation. MNP is a trademark of Microcom, Inc.
Other trademarks mentioned in this document are trademarks of their
respective companies.





This document is copyrighted. All rights are reserved. This document may
not, in whole or part, be copied, photocopied, reproduced, translated or
reduced to any electronic medium or machine-readable form without prior
consent, in writing, from Hayes Microcomputer Products, Inc.

Copyright 1993 Hayes Microcomputer Products, Inc.
All rights reserved. Printed in U.S.A.



Note: This version of the "Hayes AT Command Reference for OPTIMA and
ACCURA Products" is a special version edited for bulletin-board
downloading. As a plain ASCII character file, it therefore does not
contain the graphic elements provided in the printed version.


The following graphic characters are used to denote the start of
Chapters, 1st Level Headings, 2nd Level Headings, and Table Headings:

Chapter Headings are preceded by:
=========================================================================

1st Level Headings are preceded by:
*************************************************************************

2nd Level Headings are preceded by:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Table Headings are separated from table listings by:
-------------------------------------------------------------------------


=========================================================================
Table of Contents


Chapter 1: Introduction

Scope
Organization of This Document
Conventions
Hex Notation


Chapter 2: Basic Command Interface

Overview
Modes
DTE Interface Speeds
AT Speed
Autobaud	
Line Speed
Connect Speed
Response Speed
Character Formats
General
Stop Bits
Length And Parity
Command Processing
Overview
Command Process
AT Entry
Command Entry And Editing
Command Delineation
A/ The Repeat Command
Command Execution
Command Validity
Information Text
Result Codes
Execution Time
Assumed Zero Suffixes
Out-of-Range Suffixes


Chapter 3: Extended Command Syntax

General
Action Commands
Command Syntax
Test Command
Invalid Syntax
Parameter Commands
Write Parameter Value
Read Parameter Value
Test Parameter
Parameter Values
Command Termination
Strings
Compound Value Strings
Allowed Characters
Spaces
Special Value Formats


Chapter 4: AT Commands

General
A - Answer Command
Bn - Communications Options
D - Dial Command
En - Select Command Character Echo Option
Hn - Control The Switchhook
I0 - Identify The Product Code
I2 - Perform ROM Checksum Test
I7 - Version Number
Ln - Select Speaker Volume Level
Mn - Select Speaker Function Option
Nn - Select Negotiate Handshake Option
On - Go Online Command
P - Select Pulse Dialing Method
Qn - Select Result Code Option
Sn= - Write To An S-Register
Sn? - Read An S-Register
T - Select Tone Dialing Method
Vn - Select Response Format Option
Wn Select Extended Result Code
Xn Select Call Progress Option
Yn Select Long Space Disconnect Option
Zn Perform Soft Reset
&An - Select Originate/Answer Role For Autoanswer
&Cn - Select Data Carrier Detect Option
&Dn Select Data Terminal Ready Option
Dumb, switched
Smart AT, switched
Timing of DTR Off-To-On Transitions
Timing of DTR On-To-Off Transitions
DTR-Initiated Hard Reset (&D3 in effect)
&F - Load Factory Default Profile
&Gn - Select Guard Tone Option
&Kn - Select Flow Control Option
Transparent flow control
&Pn - Select Pulse Dialing Parameters
&Qn - Select Communications Mode Option
&Rn - Select RTS/CTS Option
&Sn - Select Data Set Ready Option
&T0 - Terminate Test In Process
&T1 - Initiate Local Analog Loopback
&T3 - Perform Local Digital Loopback
&T4 - Enable Granting Of RDL Requests
&T5 - Deny Granting Of RDL Requests
&T6 - Initiate Remote Digital Loopback
&T7 - Initiate RDL With Self Test
&T8 - Local Loopback With Self Test
&T19 - Perform RTS/CTS Cable Test
&Un - Disable Trellis Coding
&V - View Configuration Profiles
&Wn - Store Active Profile
&Xn - Select Sync Transmit Clock Source
&Yn - Select Stored Profile For Hard Reset
&Zn= - Store Telephone Number
, <comma> Perform Pause
= - Write To An S-Register
? - Read An S-Register
P - Select Pulse Dialing
T - Tone


Chapter 5: Result Codes

Basic Result Codes
Extended Result Codes


Chapter 6: S-Registers

Introduction
Scope
Command Lines
Default Value
Types
Behavior Of Unimplemented S-registers
Classifications Of S-registers
Value Evaluation Rules
Summary Of S-register Behaviors
S0 - Ring After Which To Answer
S1 - Ring Count
S2 - Hayes Escape Character
S3 - Carriage Return Character
S4 - Line Feed Character
S5 - Backspace Character
S6 - Wait Before Blind Dialing
S7 - Wait For Carrier
S8 - Pause Time For Comma
S9 - Carrier Recovery Time
S10 - Lost Carrier Hang Up Delay
S11 - DTMF Dialing Speed
S12 Hayes Escape Guard Time
S16 - Test in Progress
S18 - Modem Test Timer
S19 - AutoSync Options
S25 - Detect DTR Change
S26 - RTS To CTS Delay Interval
S30 - Inactivity Timeout
S31 - XON Character
S32 - XOFF Character
S36 - Negotiation Failure Treatment
S37 - Desired DCE Line Speed
S38 - Hang-up Timeout
S43 - Current Line Speed
S44 - Framing Technique
S46 - Protocol/Compression Selection
S48 - Feature Negotiation Action
S49 - Buffer Low Limit
S50 - Buffer High Limit
S70 - Maximum Number of Retransmissions
S73 - No Activity Timeout
S82 - Break Selection
S86 - Connection Failure Cause Code
S91 - Select Dial-up Line Transmit Level
S95 - Extended Result Code Bit Map
S97 - V.32 Late Connecting Handshake Timing
S105 - Frame Size
S108 - Signal Quality Selector
S109 - Carrier Speed Selector
S110 - V.32/V.32 bis Selector
S113 - Calling Tone Control
S121 - Use of DTR
S141 - Detection Phase Timer
S142 - Online Character Format
S144 - Autobaud Speed Group Selection


Chapter 7: Modem States

Modem Functions
Major States


Chapter 8: Processes and Procedures

Answering Process
Carrier Detection
Dialing Process
Hayes Improved Escape Sequence with Guard Time
Handshaking Process
Hang-up Process
Resets
Power On Reset
Hard Reset
Soft Reset
Key Press Abort
Online State
Online Command State
Response To Ringing
General
RI Lead.
S1 Register.
RING Result Code.
RDL Process


Chapter 9: FAX Functions

Introduction
Philosophy
Modem FAX Modes
FAX Class 1 Mode
DTE Interface Leads
General FAX Operation
FAX Commands and Responses
FAX Identification Responses
FAX Commands in Data Mode
Escape From On-line State
DTE Interface Speed
FAX Class 1
General
Commands
Answer Handshake
+FAE Automatic Data/FAX Handshake
Result Codes
Flow Control
Data Commands and Registers
Commands
Special Call Setup Conditions
S Registers
References


Chapter 10: Dumb Mode

General
Dumb Mode Characteristics
Making Calls
The Dumb Strap


Chapter 11: DTE Interface
General
Clock Leads (pins 15, 17, 24)
Clear to Send (CTS) - pin 5
Data Set Ready (DSR) - pin 6
Data Terminal Ready (DTR) - pin 20
High Speed (HS) -  pins 12 and 23
Receive Data (RD) - pin 3
Ring Indicator (RI) - pin 22
Received Line Signal Detector (RLSD) - pin 8
Request to Send (RTS) - pin 4
Send Data (SD) - pin 2


Chapter 12: Modem LEDs

AA - Auto Answer
CD - Carrier Detection
HS - High Speed
MR - Modem Ready
OH - Off Hook
RD - Receive Data
SD - Send Data
TR - Terminal Ready


Chapter 13: Relays

Line
Phone


=========================================================================
Chapter 1
Introduction


*************************************************************************
Scope

This document contains information on the Hayes Strandard AT Command Set
for the Hayes OPTIMA and ACCURA modem products including the V.FC (TM)
(Fast Class) type modems.

Modems that support the Rockwell 28.8 kbit/second modulation are
identified as V.FC in this document. Some features mentioned in this
Reference are specific to OPTIMA or ACCURA products, please check the
documentation supplied with your modem to determine which features are
supported by the modem.


*************************************************************************
Organization of This Document

This chapter offers introductory information. Subsequent chapters cover
the following:

*	Command syntax
*	Extended command syntax
*	AT commands
*	Result codes
*	S-registers
*	Modem states
*	Processes 
*	Fax transfers
*	Dumb mode 
*	Leased-line mode 
*	DTE interface signals 
*	Modem lights 
*	Modem relays. 


***************************************************************************
Conventions

The modem offers numerous command modes such as echo/no-echo,
verbose/numeric, etc. In the following chapters, assume that certain
command modes are in effect to facilitate the discussion of the many
features of the product. In effect means either the command has been
sent to the modem or the current online communication mode is what the
command would have selected. The communication mode may be the result of
the handshake process and not due to the indicated command being sent to
the modem.

Unless specified otherwise, assume that command echo (see the E1
command), the not-quiet mode (see the Qn command), and the verbose
result codes (see the V1 command) are in effect. Refer to the En, Qn,
and Vn commands to predict modem behavior in other cases.


Also, if a CONNECT result code is referred to, the remainder, if any, of
the result code (e.g., CONNECT 9600) may have been omitted for
generality. Refer to the Xn and Vn commands for additional details on
how actual CONNECT result codes appear in specific situations.

In various places in the text, the symbols <CR>, <LF>, and <BS> have
been used to represent the carriage return character, the line feed
character, and the backspace character respectively. Generally speaking,
the symbols [, ], <, and > are part of conventions that are used only to
assist in the documentation process.

In the description of the syntax of commands, the following convention
is used:

	AT [cmds] X [parameter] [cmds] <CR>

The spaces are not required; they are used to clearly depict the
individual elements in the syntax description. AT is always at the
beginning of an AT command line, and <CR> is always at the end of a
command line. The text after the AT is the subject command whose syntax
is being described. The [parameter] indicates that this command may have
certain character(s), usually numerals, that are optionally part of the
command. If it were depicted as <parameter>, then the parameter value
would be a mandatory part of the subject command.

The [cmds] means that it is allowed, in general, to place other legal
commands before or after the subject command. Some commands cannot be
followed by other commands on the same command line. In the case
depicted above, the presence of [cmds] after the subject command means
that it may be followed by other legal commands in the same command
line.


*************************************************************************
Hex Notation

The symbol $ is used in this document to identify a hex number. For
example, $3F means 3F hexadecimal.


=========================================================================
Chapter 2
Basic Command Interface


**************************************************************************************************
Overview

This Chapter describes the basic operation of the modem command
interface to the Data Terminal Equipment (DTE).


**************************************************************************************************
Modes

The modem may be used in one of three modes:

*	smart AT
*	switched smart
*	switched dumb.

All discussion of commands applies to both smart modes.

When the modem is idle or in Online Command states (smart AT mode), the
modem accepts and executes AT commands from the DTE. The modem may also
send unsolicited result codes, such as RING and NO CARRIER.

While the modem is in smart AT mode and the Online state, it can be
caused to go to the online command state by the Hayes Improved Escape
Sequence with Guard Time, and sometimes to the idle or online command
state by a DTR signal (depending on &Dn).


*************************************************************************
DTE Interface Speeds

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AT Speed

The speed of the most recent AT command line entered into the modem from
the DTE is called the AT Speed.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Autobaud

Autobaud is the process where the modem determines the DTE speed. The
modem determines the AT Speed during the AT entry process (either Idle
or Online Command State) and during the entry of the A/ command (except
in FAX modes).

In FAX modes (when +FCLASS=1), the modem autobauds.

The modem normally recognizes commands sent by the DTE at 300, 1200,
2400, 4800, 7200, 9600, 14400, 19200, 28800, 38400, 57600, 115200, and
230400 bit/second. Register S144, if supported, can change this list of
speeds.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Line Speed

The speed at which your Hayes modem communicates with the remote modem
(after carrier handshaking) is called the Line Speed. The line speed is
determined by a negotiation process during the carrier handshake between
the two modems. Refer to Chapter 8 "Handshaking Process" for details.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Connect Speed

The Connect Speed is the DTE speed indicated by the CONNECT result code.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Response Speed

The speed that the modem uses for responses to the DTE is called the
Response Speed.

After a reset (power-up reset, etc.), the Response Speed is set equal to
the AT Speed at which the last &Wn command was given. The Response Speed
is set to the AT Speed each time a command is entered from the DTE.

The Response Speed should be set to the connect speed when a call is
connected after the CONNECT result code is sent to the DTE.

The Response Speed should be set to the AT Speed when the modem enters
the idle state after a call is cleared.


*************************************************************************
Character Formats


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
General

The modem determines the DTE character format during the AT entry
process.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Stop Bits

Commands may be sent to the modem with one or two stop bits: only the
first stop bit performs any function, and the second is ignored. The
modem's responses to the DTE always has two stop bits. This is true in
the Idle and the Online Command State.

Data characters that are transmitted and received between the DTE and
the modem has the number of stop bits preserved except as modified due
to overspeed or underspeed conditions between the modems. The data bits
may be modified when the sending modem has to delete stop bits and the
receiving modem shaves (shortens) the stop bits to correct for an
overspeed or an underspeed condition.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Length And Parity

Commands may be sent to the modem with any of the following data
formats: 7-even (7 data bits and even parity bit), 7-odd, 7-mark,
7-space, 8-none, 8-even, 8-odd, and 8-space. The modem ignores the
eighth data bit when interpreting command characters. See S142 in
Chapter 6 for the online character formats.

The word length and format of modem responses to DTE commands are
determined by the last AT command entered. The modem uses the same
character format as the DTE did during the last AT entry process.


**************************************************************************************************
Command Processing

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Overview

This section describes the structure of commands (in the form of ASCII
characters) from the DTE to the modem and replies from the modem to the
DTE. Other modem input signals that may command the modem to take some
action are covered in other sections.

Many modem parameters and some command memory are stored in user
accessible registers called S-Registers. For example, S-register S3
contains the decimal value of the <CR> character. S-Register behaviors
and definitions are discussed in Chapter 6.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Command Process

The command process is defined to start while the modem is in idle or
online command states, and the modem detects a start bit from the DTE.
The command process ends under any of the three following conditions:

(1) when the start bit is not from an AT, at, A/, or a/; or

(2) during the 500 microseconds following the result code, transmission
is completed; or

(3) when certain other processes are started (e.g., handshaking or hard
reset).

While the command process is active, the modem is determining the AT
Speed and parity, accepting commands and corrections, pausing before
starting command execution, executing commands (including sending
information text to the DTE), sending result codes, and taking a maximum
of 500 microseconds to prepare for another command.

The modem does not send result codes to the DTE during the command
process except for the result codes generated by execution of the
command line. The RING result code is suppressed.

You can echo characters from the DTE with the E command. If echoed, the
modem sends a received character to the DTE. Characters that are ignored
are still echoed if you turn on the echo function with command En. All
eight bits of an input are echoed, regardless of parity. In some modem
implementations, the duration of bits (pulses) of echoed characters may
jitter up to 1/16 of the bit duration at the highest DTE speed.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
AT Entry

Most commands are sent to the modem in the format: ATxxxx<CR>, where
<CR> is the character defined to represent a carriage return and xxxx
represents an AT command. For example, ATE1 enables off-line character
echo. The AT can be in upper or lower case but not mixed case. The modem
determines the DTE's speed (AT Speed) from the A (or a). The DTE's speed
is noted and constitutes an important modifier for some command
alternatives.

Notes:
1: If the modem determines that the first characters of a new command
line are not AT or A/ several times in a row, then the modem may ignore
characters from the DTE for up to 2 ms. This is to avoid processing what
is likely to be a string of nonsensical characters.

2: Echoed characters and result codes may be sent to the DTE at 500 or
1000 cps instead of at the full DTE speed.

3: The modem may be able to accept the beginning of the next command
line immediately after sending a result code.

In the following chart the rows represent the cumulative elapsed time
required to perform the command.

Entry/Edit 		Modem 	Execute 		Send Result 	Modem 
from DTE [1]		Pause [2]	Commands [3] 	Code 		Delay [4]
-------------------------------------------------------------------------------------------------------------------------
AT commands		<CR> 125 ms	execute 		result 		500 us 
AT commands 	^X 125 ms	no action		OK 		500 us 
A/ (no commands)	125 ms 	execute 		result 		500 us 


Notes: 
1: Only the "commands" can be edited.
2: The 125 ms pause permits additional characters from the DTE (e.g.,
<LF>) that is ignored.
3: The execution of each command includes the modem sending info-text to
the DTE before the next command is executed.
4: These 500 microseconds are the maximum delay permitted for the modem
firmware to prepare again to accept an AT entry from the DTE.

The binary representation of ASCII characters a and A are 1000011P and
1000001P, respectively, with the left most bit sent first and where P
represents the parity bit. The modem estimates the duration of the start
bit that precedes the leading 1 bit of a or A to determine the DTE's
speed. The bits of the A or a and T or t are checked to determine the
parity used by the DTE, if any.

Characters that may precede the AT are ignored. That is, a string such
as ZXDBNMJAAT is interpreted as AT. All characters that follow the AT
are treated as commands.

The leading A and T of a command line are checked to determine DTE's
speed (AT speed) and parity. If the first character of a command line is
not an A (or a), it is ignored. If an A is not followed by a T or a /,
then the A is ignored.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Command Entry And Editing

A command line is a string of characters sent from a DTE to the modem,
while the modem is in a command state (idle, on-line command or analog
loopback self-test state) that starts with AT and ends with <CR>.

Spaces in a command line, after AT, are echoed if command echo is
enabled but are ignored by the modem, except if part of a string
variable input. Spaces are retained in the command line buffer. Spaces
sent to the modem by the DTE as part of a string variable are included
in the variable.

The maximum number of characters in a command line, excluding the <CR>,
the AT, is 255. If more than 255 characters are entered before the <CR>,
then the modem returns ERROR after the <CR> is entered and does not
execute any of the command line. The command buffer is cleared and the
modem then waits for a new AT command.

The characters of a command line that follow the AT may be corrected by
entering backspace characters to erase them. The backspace character is
defined by S5, and its default value is the ASCII backspace.

The modem determines if a received character is <CR> then <BS> before
any further decoding. This helps to assure <CR> and <BS> are recognized
even if they are defined to be characters that the DTE uses for other
purposes.

The Ctrl-X character (ASCII CAN) tells the modem to clear its command
line buffer and ignore the command line. The Ctrl-X is not followed by a
<CR>; it is executed immediately, terminating the command process, and
produces the OK result code.

The modem's response to a change in DTE's Speed during the entry of a
command line is not defined.

Except for character echo during command entry, simultaneous
communications between the DTE and modem may result in undefined
behavior. Therefore, entering commands to the modem during info-text or
result codes is not recommended. The results of command entry which
interrupts or which is interrupted by a RING or NO CARRIER result code
is unspecified.

Generally, when the DTE sends a <BS>, the modem responds by sending
<BS><space><BS> back to the DTE. If E0 is in effect, <BS> does not
result in any response screen display in any case. This sequence is
intended to write over the last-typed character on the terminal screen
and leave the cursor positioned there. However, if the DTE sends a
string of <BS> characters, the modem may not be able to respond to all
of them because it attempts to send three characters to the DTE for each
received <BS>, thereby resulting in undefined behavior due to
simultaneous communication between the DTE and the modem.

When the DTE sends a <BS> to the modem as if to backspace over the T of
the AT, then the modem responds by sending <BS>T. On a terminal screen,
the AT would not appear to be removed. Also, if the DTE had sent at,
then the screen would depict aT after responding to a <BS> character.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Command Delineation

A semicolon may be used to delineate commands on a command line. That
is, the end of a command may be marked by a semicolon and other commands
may follow on the command line.

This use of the semicolon was defined for extended command syntax
commands and is valid for all commands.

The command line AT; is valid and returns the OK result code. 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A/ The Repeat Command

The A/ or a/ command instructs the modem to re-execute the last command
line. This command is not preceded by AT and is not followed by <CR>.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Command Execution

The modem waits a nominal 125 ms after the <CR> terminates command entry
before it begins execution of the command line. This allows the DTE to
send a <LF> after the command line. The <LF> and any other characters
received during the 125 ms wait are echoed by the modem, but they are
ignored.

An AT command line consists of one or more individual commands. The
execution of the command line consists of the left-to-right execution of
each command followed by the reporting of a result code for the entire
line. (For more details, refer to "Result Codes" in this Chapter.) The
execution of each command in that line may include taking some action,
changing a configuration, and/or reporting information text to the DTE.
(For more details, refer to the "Information Text" in this Chapter.)
Some commands may change nonvolatile information in the mode.

There are two special exceptions of the left-to-right execution of the
commands in the command line: (1) if the execution of a command produces
the ERROR result code, or (2) if the executed command cannot be followed
by additional commands, then the remaining commands are ignored.

An ERROR is produced during command execution if any of the following
conditions occur:

*       command letter, prefix, or suffix is invalid in the current
        context (unless otherwise specified),

*       command qualifier (e.g., = or ?) is invalid in the current
        context,

*	command line is too long (see the D command in Chapter 4).

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Command Validity

All commands are valid in both the on-line and off-line states unless
otherwise noted.


**************************************************************************************************
Information Text (Info-Text)

The modem's execution of a command line may include sending information
text (info-text) to the DTE prior to sending the result code. Some
commands produce info-text, others do not. The modem outputs the
info-text, if any, for each command before executing the next command on
the line. To determine the actual info-text, associated with a specific
command, refer to the command definitions in Chapter 4.

Each info-text message may be preceded and followed by <CR><LF>
depending upon which Vn command is in effect. Refer to the Vn command in
Chapter 4 for formatting rules. Note that an info-text message may
contain multiple lines, and the <CR><LF>'s between these lines are not
affected by Vn (although they are still programmed by registers S3 and
S4, respectively). Several commands have info text that violates these
rules, however, in order to assure backwards compatibility of Hayes
products. The exception is the I2 command. The <CR><LF> formats for I2
are described in Chapter 4.


**************************************************************************************************
Result Codes

A result code is sent to the DTE in response to the execution of a
command line, and it may also result from some other conditions (e.g.,
RING) as described later. Refer to Chapter 5 for a list of all the
possible result codes.

Every command line causes one result code message to be sent to the DTE.
Normally, this is the OK result code, but there are two general
exceptions when it is not: (1) if the execution of a command results in
an error, then the ERROR result code is produced, and (2) if call
establishment or carrier handshaking function is initiated by a command,
then one of the other result codes is produced. These other result codes
are specified by the command definitions in the chapters to follow.

Result codes may be turned-off or turned-on by the Qn command. Result
codes are sent in either a verbose mode or in a numeric short form,
depending upon which Vn command is in effect. The modem usually sends
one result code, such as OK, to the DTE after executing a command. One
exception is after the D command; several result codes may be sent after
a connection is established.

The DCE accepts a new command 0.5 ms after the last character of a
result code or group of result codes has been sent to the DTE. The last
character is usually Ctrl-J (line feed).


**************************************************************************************************
Execution Time

Generally, the execution of most commands proceeds as fast as the modem
processor can perform the indicated function. There are, however,
constraints on command execution time specified by the command
definitions in the chapters to follow. The execution time for each
command includes the time required to send info-text (refer to
"Information Text" in this Chapter) which is dependent upon the Response
Speed. The time required to execute the entire command line also
includes the time required to send the result code which is dependent
upon the Response Speed.

The formula for the total time of execution of a command line follows:

	TCL = 125 ms + TC1 + TC2 + ... + TRC

where:

	TCn = command execution time including info-text time 
	TRC = result code time.

Note: Information text and result code times depend on the Response
Speed, the number of characters sent, and which Vn and Qn commands are
in effect.


**************************************************************************************************
Assumed Zero Suffixes

Many commands are of the form Zn, where n is a number. If n is not
included, the modem assumes 0 was intended. Thus Z is the same as Z0.


**************************************************************************************************
Out-of-Range Suffixes

All suffixes outside the specified range cause an ERROR result code and
abort the command (and the rest of the command line). Chapter 4 lists
suffixes for each command.


=========================================================================
Chapter 3
Extended Command Syntax


**************************************************************************************************
General

Extended commands are action or parameter commands for which a special
syntax is used. This chapter describes the syntax rules.

Extended commands may set DCE parameter values (parameter commands) or
initiate actions (action commands). Action commands may be accompanied
by parameter values that affect the outcome of the command.

Action commands may be executed or tested. Parameters may be set, read,
or tested.


**************************************************************************************************
Action Commands

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Command Syntax
	<CMD_NAME>[=<value>] or

	<CMD_NAME>[=<compound value string>]

Action commands may be accompanied by values (numbers) or strings upon
which the command acts.

If an extended command is supported, the DCE executes the command as
defined in the command description. Otherwise, the DCE returns the ERROR
result code.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Test Command
-----------------------------------------------------------------------------------------------------------------------------
Syntax	<CMD_NAME>=?

                This command is sent by the DTE to determine if the
                named command is implemented in the DCE, and, if so, the
                range of values supported. If the named command is
                supported, the DCE returns the OK result code; ERROR
                otherwise.

                If the command supports a range of values or compound
                value strings, the DCE reports the range of values or
                compound value string as described below, then returns
                the OK result code.
		
                The supported values are presented in information text
                format, as an ordered list preceded by a ( (left
                parentheses character) and followed by a ) (right
                parentheses character), ASCII 40 and 41 (decimal). If
                the value is a compound one, the supported values are
                reported, enclosed in parentheses and separated by
                commas. An ordered list consists of a single value, a
                set of values separated by commas, or as two values
                separated by a hyphen to denote an inclusive range of
                values.
		
		An example DCE response to a parameter test is:

			<CR><LF>(0-255),(0-2,5)<CR><LF>

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Invalid Syntax

The syntax <CMD_NAME>? is used to read a parameter value. If this syntax
is used with an action command, the DCE returns the ERROR result code.


**************************************************************************************************
Parameter Commands


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Write Parameter Value
Syntax 	<CMD_NAME>=<value> or

<CMD_NAME>=<compound value string>.

If the value or value string is supported, the parameter is set to the
indicated value and the DCE returns the OK result code. Otherwise the
DCE returns the ERROR result code.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Read Parameter Value
Syntax 	<CMD_NAME>?
-----------------------------------------------------------------------------------------------------------------------------
                If the command is supported the DCE returns the current
                value of the parameter, followed by the OK result code.
                Otherwise, the DCE returns the ERROR result code.
		
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Test Parameter
-----------------------------------------------------------------------------------------------------------------------------
Syntax 	<CMD_NAME>=?

                This is sent by the DTE to determine the parameter
                values supported by the DCE.

                If the command is supported, the DCE returns the
                supported parameter values, using the information text
                format, as an ordered list preceded by a ( (left
                parentheses character) and followed by a ) (right
                parentheses character), ASCII 40 and 41 (decimal).

                If the value is a compound one, the supported values are
                reported, enclosed in parentheses and separated by
                commas. An ordered list consists of a single value, a
                set of values separated by commas, or as two values
                separated by a hyphen to denote an inclusive range of
                values.

		An example DCE response to a parameter test is:

			<CR><LF>(0-255),(0-2,5)<CR><LF>

                If the command is not supported, the DCE returns the
                ERROR result code.


**************************************************************************************************
Parameter Values

Each parameter or action command that takes parameters is defined as
taking numeric or string values or a combination of both. Parameter
values may be single or compound (more than one). The DCE returns the
ERROR result code if the DTE sends an invalid parameter string.

Numeric parameter values may be expressed in hexadecimal or decimal, as
prescribed by the individual command definitions.


**************************************************************************************************
Command Termination

All extended commands are terminated by an ASCII semicolon (decimal 59)
or CR character (decimal 13). More commands may follow the semicolon.


**************************************************************************************************
Strings

When a string is to be used by an action command or used as a parameter,
the string is appended to the command name by adding an equals sign (=)
to the command name, with no intervening spaces, followed by the string
enclosed in quote symbols ("). If the quote symbol is to be included as
part of the string, the symbol is used twice. For example
"abcd""hello""" includes the string "hello" within the quoted string,
producing the string: abcd"hello".


**************************************************************************************************
Compound Value Strings

Several values or strings may be associated with an extended command by
placing them serially on the command line with commas between the values
or strings. An example is the following:

	<CMD_NAME>=<value1>,<value2>,"<string>"


**************************************************************************************************
Allowed Characters

Strings consist of the ASCII characters space through tilde (decimal 32
through 126). Control characters with decimal values less than 32 are
not allowed and are ignored with the exception of <CR>.


**************************************************************************************************
Spaces

Spaces between = and <value> or <string> are ignored by the DCE. Spaces
within a string are considered part of the string. Extended command name
and its equals sign (=) do not have intervening spaces.


**************************************************************************************************
Special Value Formats

Values may have special formats if so defined by an extended command
description. For example, a value may have two parts as in the following
format: 2:4.


=========================================================================
Chapter 4
AT Commands


**************************************************************************************************
General

With a few exceptions, command names contain a prefix (optional), a
letter, and a suffix (optional).

Prefix 		&, %, etc. 
Letter 		A, B, etc. 
Suffix 		a number, such as 5

		Following are several examples:
		
		Example: 	&K5 	prefix = &
					letter = K
					suffix = 5
		
		Example: 	D 	letter only
		
		Example: 	I0 	letter and suffix
		

In the following specifications, the suffix may be represented generally
by the letter n.

Do not insert spaces in command names. The modem ignores spaces between
commands.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A - Answer Command

----------------------------------------------------------------------
Command 
Line Format		AT [cmds] A <CR> 

Suffix Values		none 

Factory Default	N/A

Stored by &Wn	N/A

Displayed by &V	N/A

Description             The A command instructs the modem to execute the
                        Answer Process, which may quickly lead to
                        executing the Handshaking Process. Refer to
                        "Answer Process" and "Handshaking Process" in
                        Chapter 8. The A command is not valid in the
                        Online Command State or if either &Q2 or &Q3 is
                        in effect.
		

Result Codes		CONNECT - if a connection is established. (Refer to 
                        "Handshaking Process" in Chapter 8.)

                        NO CARRIER - if a connection cannot be
                        established or if aborted by a character from
                        the DTE. (Refer to the Answer Process and the
                        "Handshaking Process" in Chapter 8.)

                        ERROR - if in Online Command State or &Q2 or &Q3
                        is in effect when A is issued
			
                        OK - if aborted by DTR ON-to-OFF whenever
                        certain combinations of &Dn and &Qn are in
                        effect. Refer to the "&Dn" command definition in
                        this Chapter.
			
Execution Time	See "Answer and Handshake Processes" in Chapter 8.

DTE Interface 
Lines Affected		DSR, RLSD, HS (pin 12 and pin 23).

LEDs Affected		OH, CD, HS.

Aborting events	"Key-press abort" aborts Answer and Handshaking Processes.

                        DTR ON-to-OFF aborts Answer and Handshaking
                        whenever certain combinations of &Dn and &Qn are
                        in effect. (Refer to "&Dn" command definition in
                        this Chapter.)
			
Cross Reference 	Commands - &Mn, &Qn 
			S-registers - S7 
			DTE signals - DTR, DSR, CTS, RLSD, HS 
			Line signals - Carrier 
			LEDs - OH, CD, HS 
			Relays - Auxiliary, Line, Phone 
			Answering process 
			Handshaking process
			

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bn - Communications Options

-----------------------------------------------------------------------------------------------------------------------------
Command 		AT [cmds] B[suffix] [cmds] <CR> 
Line  Format

Suffix Values		See list below 

Factory Default	See feature table

Stored by &Wn	yes

Displayed by &V 	yes

Description             This command allows simultaneous selection of
                        more than one n suffix; however, there are
                        groups of n values and only the last n chosen
                        from a group is in effect within that group.
			
                        The B command is used to select the
                        communication standard for data calls. The value
                        of suffix n defines the desired communications
                        standard setting at a particular modem line
                        speed.
			


B Command

The Hayes OPTIMA and ACCURA products support the following B commands.

		B0 - CCITT V.22 when line speed is 1200 bit/second. 
		
		B1 - Industry Standard 212A when line speed is 1200 bit/second.
			
                B2 - V.23 originate: T75/R1200 when DTE speed is
                     1200 bit/second.
                   - V.23 answer: T75/R1200 when DTE speed is
                     1200 bit/second.
			
                B3 - V.23 originate: T1200/R75 when DTE speed is
                     1200 bit/second.
                   - V.23 answer: T1200/R75 when DTE speed is
                     1200 bit/second.
			
		B6 - V.26 bis when line speed is 1200 bit/second. (HDX)
			
		B15 - V.21 when line speed is 300 bit/second. 
			
		B16 - Industry Standard 103 when line speed is 300 bit/second.
			
		B30 - V.22 bis when line speed is 2400 bit/second. 
			
		B32 - V.26 bis when line speed is 2400 bit/second. (HDX)
			
		B41 - V.32 when line speed is 4800 bit/second. 
			
		B52 - V.32 bis when line speed is 7200 bit/second.
			
		B60 - V.32 when line speed is 9600 bit/second. 
			
		B64 - V.FC when line speed is 9600 bit/second.
			
		B70 - V.32 bis when handshake begins at 12000 bit/second. 
			
		B71 - V.FC when handshake begins at 12000 bit/second.
			
		B75 - V.32 bis when handshake begins at 14400 bit/second. 
			
		B76 - V.FC when handshake begins at 14400 bit/second.
			
		B81 - V.FC when handshake begins at 16800-28800 bit/second. 
			


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
D - Dial Command

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] D [Digits and Modifiers] [ ; [cmds] ] <CR>

Factory Default	N/A

Stored by &Wn	N/A

Displayed by &V	N/A

Description             Instructs the modem to execute the Dialing
                        Process (i.e., go off hook and process the dial
                        string), which may lead to executing the
                        Handshaking Process. The dial string is a
                        combination of dial digits and dial modifiers.
                        If the modem is off hook, it neither initially
                        waits nor attempts to detect dial tone before
                        proceeding. The D command is not valid in the
                        Online Command State or if either &Q2 or &Q3 is
                        in effect.
			
                        The D command may only be followed by dial
                        digits and modifiers (if any), except for when
                        the ; is used: in this case, the ; (semicolon)
                        may only be followed by commands (if any).
                        Invalid dial modifiers in the dial string (e.g.,
                        "-") are ignored.
			
                        Refer to "Dialing Process and the Handshaking
                        Process" in Chapter 8.
			
                        The Dial Digits are: 0, 1, 2, 3, 4, 5, 6, 7, 8,
                        9, A, B, C, D, #, and *.
			
                        Only the S=n dial modifier has any suffixes.
                        These are displayed by the &V command only when
                        they are a part of a stored number (refer to the
                        &Zn= command) except for P and T, which are also
                        commands. None of these may be stored by &Wn
                        command except for P and T.
			
                        P - Select Pulse Dialing - This dial modifier
                        instructs the modem to use pulse dialing. Dialed
                        digits are pulse-dialed in subsequent digits of
                        the current dial string and in all future dial
                        strings until a T command or dial modifier is
                        executed.
			
                        R - Originate Call In Answer Mode - This
                        modifier instructs the modem to go into the
                        answer mode rather than the originate mode after
                        executing the dial string and starting the
                        handshake. The same result occurs if several R
                        dial modifiers are in the same dial string.
			
                        S=n - Dial Stored Telephone Number - Indicates
                        to the D command that the telephone dial string
                        n, one of four such strings that may have
                        previously been stored by an &Zn= command, is
                        processed now.

Syntax		AT [cmds] D [dial-string] S[0|=n] [ignore]<CR>

			where: 
			a. Other commands may precede the D command.
			
                        b. Non-stored dial string characters after the D
                        may precede the S.
			
                        c. The S may be followed by 0 or =n, where n is
                        0-3. Invalid n causes an ERROR result code. If
                        the character immediately following the S is not
                        an = or a 0 then all characters after the S are
                        ignored, and stored number 0 is dialed.
			
                        T - Tone - The T dial modifier instructs the
                        modem to send DTMF tones while dialing. Dialed
                        digits are tone dialed until a P command or P
                        dial modifier is selected.
			
                        W - Wait For Dial Tone - If a valid dial tone is
                        detected, the dial characters or modifiers
                        following the command are executed. If dialtone
                        is not detected before the specified time then
                        the modem returns the NO DIALTONE result code
                        and clears the call. If a busy signal is
                        detected instead of dial tone, the modem returns
                        the BUSY result code and clears the call,
                        abandoning subsequent instructions in the dial
                        string or on the command line.
			
                        Comma (,) Pause - The comma dial modifier
                        instructs the modem to pause for the amount of
                        time specified by S8 (in seconds) before
                        processing the next character in the dial
                        string. This modifier is also used as a command.
			
                        Quotes (") - Telephone numbers may be enclosed
                        in double quote symbols ("). Enclosed characters
                        may be digits or letters. Digits (0-9) are
                        interpreted as numbers. Letters are interpreted
                        as numbers according to the following table.
                        Quote symbols are used in pairs; the first of a
                        pair begins the quoted string, the second of a
                        pair ends the quoted string. Subsequent quotes
                        may be used; that is, several sections of a dial
                        string may be individually enclosed in quotes.
                        If a closing quote is not sent to the modem
                        before the dial command is ended (by <CR> or ;),
                        then the modem treats the dial string as if a
                        closing quote occurred before the ending
                        character.
			
			Letters 	Number 	Letters 	Number 
			-----------------------------------------------------------------------------
			ABC 		2		MNO		6
			DEF 		3		PRS 		7
			GHI 		4		TUV		8
			JKL		5		WXY		9

                        Exclamation mark (!) - Flash - Flash is a dial
                        modifier that is also known as hookflash, or
                        register recall. It instructs the modem to go
                        on-hook (for a time that is specific to the
                        country) then return off-hook. The modem, if
                        capable, lowers the off-hook resistance 100 +/-
                        10 ms before going on- hook for the flash and
                        returns the off-hook resistance to normal 100
                        +/- 10 ms after the flash. This causes the flash
                        duration to be 200 ms plus the length of the
                        flash.

                        @ - Wait For Quiet Answer - This dial modifier
                        instructs the modem to look for line signal
                        (ringback) followed by 6.5 +/- 0.5 seconds of
                        silence (no detectable signal in call progress
                        frequency band) up to the time specified in S7.
                        If quiet answer is detected, the dial modifiers
                        following the command are executed. If busy is
                        detected, the modem returns a BUSY result code
                        and goes to the hang-up process, aborting
                        further execution of the dial string.

                        Note: At least 6 seconds of silence is required
                        to cover the ringing cadence of certain European
                        countries.
			
                        Note: Busy signal detection is enabled during
                        execution of the W, @, and $ dial modifiers.

Result Codes            BUSY - if busy is detected (independent of Xn
                        command selected).

                        NO ANSWER - if quiet answer is not detected
                        within time specified by S7.

                        Note: NO ANSWER result code is used only by the
                        @ dial modifier.

                        $ - Wait for bong tone - The $ dial modifier
                        invokes the following behavior.

                        Note: Bong Tone is available on 28.8
                        kbits/second modems.

                        1. The modem waits for detection of the prompt
                        tone as follows:
			
                        a. If the modem does not detect the tone before
                        the S7 timeout occurs, then the call is
                        terminated, and the NO DIALTONE result code
                        returned.

                        b. If the modem detects the prompt tone before
                        the time limit, then the modem pauses 1 second
                        and executes the remainder of the dial string.

                        2. The prompt tone detector responds to tone 2
                        at any level between 0 dBm and -30 dBm if it
                        lasts at least 200 ms. The tone detector does
                        not respond to the following

                        *       tones outside the call progress band of
                                375 to 550 Hz,
			*	tones whose duration is less than 200 ms,
                        *       tones (such as busy tone) that go off and
                                back on in less than 1 second.

                        Note: The Bellcore definition of the prompt tone
                        is as follows:

                        Tone 1 for 60 ms, followed immediately by Tone
                        2. Tone 1: 941 and 1477 Hz, constant level, two
                        tones. Tone 2: 440 and 350 Hz, decaying with
                        time constant of 200 ms, ending after 940 ms.

                        The level of tone 1 is -10 dBm/freq. The initial
                        level of tone 2 is -10dBm/freq. at-3TLP.

			Suggested method of detecting bong tone:

                        1. Measure the initial tone level, using a 50 ms
                        observation interval.
			
                        2. Check the level again after 230 ms, again
                        with a 50-ms observation interval.
			
                        3. Detect bong tone if the second level is 7 to
                        13 dB less than the first level, otherwise
                        reject.

                        Semicolon (;) - Return To Idle State - This dial
                        modifier instructs the modem to return to the
                        idle state and wait for more commands even
                        though it has executed a dial command. The modem
                        does not proceed to the Handshaking Process
                        until an A or O or another D command is
                        processed.
			
                        The semicolon dial modifier may be part of a
                        stored telephone number and is executed by the
                        dialing process regardless of how the dialing
                        process is entered.
			


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
En - Select Command Character Echo Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] E [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	E1 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             This command instructs the modem to echo or not
                        echo commands from the DTE.
			
			E0 - Off-line character echo disabled 
			E1 - Off-line character echo enabled
			
Execution Time 	1 ms maximum

Cross Reference	DTE signals - RD 
                       LEDs - RD
			

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Hn - Control The Switchhook

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] H [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A

Description             The H command provides control over the line
                        relay, and it can cause a transition to the
                        hangup process.
			
                        H0 instructs the modem to execute the hangup
                        process if it is in one of following:
			
			*	Online Command State,
			*	Local Analog Loopback Self-test State
                        *       Online Command Substate of the Local Analog
                                Loopback Process.
			
                        If the modem is online and data transfer is
                        still pending, then the modem stays connected
                        for the time set by S38 in an attempt to
                        complete the transfer of these data. If the data
                        is sent before the time limit, the modem hangs
                        up and returns the OK result code. If the data
                        is not sent before the time limit, the modem
                        hangs up and returns the NO CARRIER result code.
                        See the S38 section in Chapter 6 for more
                        details.
			
                        H1 instructs the modem to go off-hook, but does
                        not cause execution of the Handshaking Process.
                        If the modem is already in the Online Command
                        State, then H1 has no effect.
			
                        H2 causes operation of the line relay but not
                        the phone relay. This feature is used in some
                        1200 bit/second modems.
			


Execution Time  H0 - Depends on the modulation in use. 500 ms maximum,
                        in async and sync Modes that do not use echo
                        cancellation. Four seconds if modulation uses
                        echo cancellation. See Chapter 8. The time is
                        determined by S38 (def=20s) in buffered modes.
			
			H1: 10 ms maximum

DTE Interface Lines
Affected 		DSR, RL, SD, HS

LEDs Affected 		CD, HS, MR, OH

Cross Reference	Commands - Ln, Mn, &Dn, &J, &Tn 
			Line signals - Carrier, Ringing voltage 
			Relays - Auxiliary, Line


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I0 - Identify The Product Code

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] I [0] [cmds] <CR> 

Suffix Values		0 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             I0 is used to report the highest line speed
                        supported by the modem according to the
                        following table.
			
			Highest line speed	I0 response (bit/second) 
                        ------------------------------------------------------
                        2400                    249
			9600 			960 above 9600 actual speed in
						bits/second 
			
                        At all supported line speeds above 9600
                        bits/second, the I0 command reports the actual
                        highest supported line speed in bits/second.
			

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I2 - Perform ROM Checksum Test

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] I2 [cmds] <CR> 

Suffix Values		N/A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             I2 instructs the modem to verify the ROM
                        checksums. Depending on whether the ROM
                        checksums are determined to be correct, the
                        modem produces an info-text that resembles a
                        verbose result code. The actual result code
                        associated with this command is OK.
						
                        When the checksum is found to be valid, the
                        info-text produced is as follows:
			
				OK
			
                        where the associated <CR> and <LF> characters
                        follow the rules defined for info-text messages
                        in Chapter 3. Thus, when V0 is in effect, and
                        the ROM checksum ID verified, the modem response
                        to the ATI2<CR> command line is as follows:
			
				OK<CR><LF>0<CR>
			
                        where the <CR> and <LF> characters are
                        controlled by registers S3 and S4, respectively.

                        When the ROM checksum fails, the modem responds
                        by issuing the following info-text:

				ERROR

                        where the associated <CR> and <LF> characters
                        follow the rules defined for info-text messages
                        in Chapter 3. Thus, V1 is in effect, and the ROM
                        checksum is invalid, the response to the
                        ATI2<CR> command line is as follows:

				<CR><LF>ERROR<CR><LF><CR><LF>OK<CR><LF>

                        where the <CR> and <LF> are controlled, as
                        usual, by registers S3 and S4, respectively.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
I7 - Version Number

-----------------------------------------------------------------------------------------------------------------------------
Description		The I7 command invokes the following info-text.


			Note: The I7 command is not supported in all OPTIMA and 
			ACCURA products.

<name>                  This is the abbreviated name and speed that is
                        used on the label. A maximum of 12 characters is
                        allowed for the name. Example: VSM9600.

<number>                This is the 4-character model number of the
                        product. Example: 0123.

<country>               This is the two-character country code of the
                        country for which the modem is intended.
                        Example: US.

<version>               This is the version control number of the
                        product. The format of <version> is xx.yy. The
                        version consists of a maximum of 5 characters,
                        left justified. Example: 1.12.

Copyright <year>        The copyright notice refers to the info-text
                        invoked by the I7 command. The <year> is 4
                        characters. Example: 1992.

			An example response to I7:

                        SM09600, Model 0123US, Version 2.3
                        Copyright 1992 Hayes Microcomputer Products, Inc.

Command Line 
Format		AT [cmds] I7 [cmds] <CR> 

Suffix Values		N/A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Reference 		VSET command


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ln - Select Speaker Volume Level

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] L [suffix] [cmds] <CR> 

Suffix Values		0 through 3 

Factory Default	L2 

Stored by &Wn	yes 

Displayed by &V	yes

Description             This command determines the modem's speaker
                        volume setting.

			L0 - Low speaker volume 
			L1 - Low speaker volume 
			L2 - Medium speaker volume 
			L3 - High speaker volume

                        The volume setting changes immediately and
                        affects the sound output level if the speaker is
                        enabled (see the Mn command), the modem is off
                        hook, and a signal is present on tip and ring.

Execution Time	100 ms maximum

Cross Reference 	Commands - Mn


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Mn - Select Speaker Function Option

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] M [suffix] [cmds] <CR> 

Suffix Values		0 through 4 

Factory Default	M1 

Stored by &Wn	yes 

Displayed by &V	yes

Description		This command selects the speaker option.

			M0 - Speaker always off.

			M1 - Speaker on while off hook until carrier detected.

                        M2 - Speaker always on while off hook; stays on
                        after carrier is detected.

                        M3 - Speaker off as digits are dialed, then on
                        until carrier is detected.

                        When dialing progress is reported, each digit or
                        dial modifier character is sent to the DTE
                        before the item is acted upon by the modem
                        (within 20 ms before). For example, the first
                        dialed digit would be sent to the DTE just
                        before it is sent to the PSTN (Public Switched
                        Telephone Network). A comma dial modifier is
                        presented to the DTE at the beginning of the
                        pause invoked by the comma.

                        Dial tone is reported only if dial tone is
                        actually detected. Dial tone is not reported if
                        the X3 command is selected and dialing starts
                        after a timed pause and not detection of dial
                        tone.

                        Silent answer is reported if the conditions for
                        detection of silent answer are met, independent
                        of whether or not the @ dial modifier was
                        included in the dial string.

                        If the S=n dial modifier is in the command sent
                        to the modem, the modem presents the equivalent
                        dial digits and modifiers to the DTE, not S=n.

                        Even if the modem is already off hook, the
                        speaker control is immediately updated by an Mn
                        command.

Execution Time 	100 ms maximum

Cross Reference 	Commands - Dn, Ln


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Nn - Select Negotiate Handshake Option

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] N [suffix] [cmds] <CR> 

Suffix Values		0 through 5 

Factory Default	N1 

Stored by &Wn	yes 

Displayed by &V	yes

Description             The N command selects whether or not the local
                        modem performs a negotiated handshake with a
                        remote modem when the communications speed of
                        the two modems is different. Both symmetrical
                        and asymmetrical handshake procedures can be
                        selected.

			The choices for originate mode are as follows.

                        Orig-A - Handshake only at the communication
                        standard specified by S37 and Bn.
	
                        Orig-B - Begin handshake at line speed specified
                        by S37. Fallback to a lower speed is allowed.
                        The modem listens for V.23 tone (1300 Hz) and
                        300- bit/second Frequency Shift Keying (FSK)
                        carrier according to whether B15 (V.21) or B16
                        (Industry Standard 103) is selected. If one of
                        the tones is detected, the originate modem
                        attempts to connect to the detected modem type.
                        See the "Handshake Procedures" section in
                        Chapter 8.

			The choices for answer mode are as follows:

                        Ans-A - Handshake only at the communication
                        standard specified by S37 and Bn.

                        Ans-B - Negotiate according to the following
                        sequence of communication standards, starting at
                        the highest speed allowed by the value of S37:
                        V.FC, V.32 bis, V.32, V.22 bis, (V.22 or
                        Industry Standard 212), V.21, and Industry
                        Standard 103. V.22 versus Industry Standard 212
                        depends on the B command in effect.

                        Ans-C - Negotiate according to the following
                        sequence of communication standards, starting at
                        the highest speed allowed by the value of S37:
                        V.FC, V.32 bis, V.32, V.22 bis, (V.22 or
                        Industry Standard 212), V.23, V.21, and Industry
                        Standard 103. V.22 versus Industry Standard 212
                        depends on the B command in effect.

                        Note: Ans-C is the same as Ans-B if V.23
                        modulation is not available.

                        The following table associates the options with
                        Nn commands.

			Option	N0 	N1 	N2 	N3 	N4 	N5
                        --------------------------------------------------
			Orig-A 	X			X	X 	
			Orig-B 		X	X 			X
                        Ans-A           X                               X
			Ans-B 		X		X 		
			Ans-C 			X 		X	


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
On - Go Online Command

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] O [suffix] <CR>

Suffix Values		0, 1, 3 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             If the modem is in the Online Command State,
                        then the O0 command causes it to go to the
                        online state of the previously established
                        connection. If the O1 command is issued, then
                        the modem goes to Online state and retrains its
                        adaptive equalizer, if it has one.

                        If the modem is off-hook in the idle state, then
                        O0 and O1 cause it to go to the handshaking
                        state. Originate or answer mode is determined
                        from the last D or A command or R dial modifier
                        that was selected. If the modem is on- hook in
                        the Idle State, or if the modem is in a test
                        state, then a command execution error results.

                        O3 is valid only in the Online Command State and
                        if rate re- negotiation is supported. The
                        command tells the modem to initiate a rate re-
                        negotiation procedure. The new rate
                        possibilities are those selected by the value of
                        S109, which must be set before issuing the O3
                        command. The value of S37 and N do not affect
                        the rate re-negotiation procedure. If rate
                        re-negotiation is not currently supported, then
                        the modem returns ERROR to the O3 command.

Result Codes            ERROR - if modem is on hook or &T1, &T3, &T6-&T8
                        is active or On cannot be executed.

                        CONNECT - if successfully returned to Online State
			
                        NO CARRIER - if O1 is issued and the equalizer
                        retrain is not successful in the time specified
                        by S7.

Execution Time	Depends on retrain procedure (per modulation type).

Cross Reference 	Commands - &T1, &T3, &T6-&T8 
			DTE signals - DTR, DSR, CTS, RLSD
			Line signals - Carrier 
			LEDs - CD, HS
			


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
P - Select Pulse Dialing Method

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] P [cmds] <CR> 

Suffix Values		none 

Factory Default	P (as opposed to "T") 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             This command instructs the modem to use pulse
                        dialing. Dialed digits are pulse dialed until a
                        T command or dial modifier is received.

Execution Time	1 ms maximum

Cross Reference 	Commands - Dn, T, P dial modifier


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Qn - Select Result Code Option

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] Q [suffix] [cmds] <CR> 

Suffix Values		0 through 2 

Factory Default	Q0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             Qn instructs the modem whether or not to give
                        result codes to the DTE.

Result Codes		Q0 - Result codes enabled 
			Q1 - Result codes disabled 
                        Q2 - Disables the RING result code. In answer
                             mode, also disables CONNECT and NO CARRIER
                             result codes.
			
Execution Time	1 ms maximum

Cross Reference	DTE signals - RD 
			LEDs - RD 
			Result Codes 
			Execution Time



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Sn= - Write To An S-Register

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format   AT [cmds] [ S [ <S-register Address> ]] = <Register Data> [cmds] <CR>

Address Values 	Refer to Chapter 6 

Data Values		Refer to Chapter 6 

Factory Default	S0 

Stored by &Wn	no 

Displayed by &V	N/A
 
Description             The command is issued as Sn=x. The value of x is
                        written to the S- register specified by n,
                        overriding the previous value.

                        If no n suffix is present, the address 0 is
                        used.

			If no x value is present, the value 0 is written.
			
			Example:

				ATS=x<CR> means S0=x 
                                AT=x<CR> means Sn=x, where n is the
                                suffix of the last named S-register.

Execution Time 	5 ms maximum

Cross Reference	Commands - Sn, Sn? 
			LEDs - AA, HS, TR


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Sn? - Read An S-Register

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] [ S [ <S-Register Address> ]] ? [cmds] <CR>

Address Values 	0 through 255 

Factory Default	S0 

Stored by &Wn	no 

Displayed by &V	N/A 

Description             The contents of S-register n are sent as three
                        decimal digits. This info- text response is
                        formatted with <CR><LF> as determined by the Vn
                        command currently in effect. If no n (suffix) is
                        present, the last register selection is assumed.
                        On power up, the default selection is 0.

			Note: ? is interpreted by the modem as Sn?.

Cross Reference 	Commands - Sn, Sn=


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
T - Select Tone Dialing Method

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] T [cmds] <CR> 

Suffix Values		none 

Factory Default	P (as opposed to "T") 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The T command instructs the modem to send DTMF
                        tones while dialing. Dialed digits are tone
                        dialed until a P command or dial modifier is
                        received.

Execution Time 	1 ms maximum

Cross Reference	Commands - Dn, P, T dial modifier


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Vn - Select Response Format Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] V [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	V1 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The Vn command determines which format to use
                        (i.e., verbose versus numeric) for info-text and
                        result codes. Refer to the table below. Note
                        that <CR> and <LF> are defined by S-registers S3
                        and S4, respectively.

				V0 - Result codes displayed in numeric form 
				V1 - Result codes displayed in verbose form

                        The following table shows the formats. See also
                        the Q command.

                        Note: The "text" of the info-text in the table
                        below may consist of multiple lines of text. The
                        formats depicted here only refer to the <CR><LF>
                        characters between info-texts and not within
                        them.

					V0			V1
                        ----------------------------------------------------
			Info-text 	text			<CR><LF> 
					<CR><LF>		text 
								<CR><LF> 

			Result codes 	numeric code 		<CR><LF> 
					<CR>			verbose code
								<CR><LF>

Result Code 		Info-text Formats

Execution Time 	1 ms maximum

Cross Reference	Information Text
			Result Codes
			Execution Time


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Wn Select Extended Result Code

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] W [suffix] [cmds] <CR> 

Suffix Values		0 through 2 

Factory Default	W0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The Wn command works in conjunction with
                        register S95 to determine which result codes are
                        used to describe the type of connection and
                        protocol, etc., that resulted from handshaking
                        and negotiation.

                        Wn allows for extended result codes in addition
                        to the CONNECT result code. When the modem is
                        operated in error-control mode (&Q5 is in
                        effect), Wn and S95 together allow you to select
                        these additional Result Codes:

			*	CARRIER 
			*	PROTOCOL 
			*	AUTOSTREAM 
			*	COMPRESSION 
			*	CONNECT.

                        Any result codes which are enabled by Wn and S95
                        are produced in the order indicated above.
                        Result codes that are not enabled by the Wn
                        command may be turned-on by setting certain bits
                        in S95. If AutoStream is not being used, then no
                        AutoStream result code is returned. Also, if the
                        connection results in PROTOCOL: NONE, then there
                        is no COMPRESSION: result code. The S95 result
                        code bit map, which has all zeros as the Factory
                        Default value, overrides the characteristics of
                        the Wn commands described below when any bit is
                        set.

                        W0- CONNECT result code reports DTE speed, and
                        if S95=0 (default), then disable all extended
                        connection result codes.

                        W1- CONNECT result code reports DTE speed, and
                        if S95=0 (default), then enable the CARRIER and
                        PROTOCOL extended result codes.

                        W2- CONNECT result code reports DCE speed, and
                        if S95=0 (default), then disable all extended
                        result codes.

                        Refer to the bit map presented with the S95
                        definition in Chapter 6.

			Notes: 
                        1) Selecting W0 and setting S95=12 (decimal) is
                        the same as selecting W1; and that selecting W0
                        and setting S95=1 (decimal) is the same as
                        selecting W2.

                        2) There is no setting of S95 that forces W2 to
                        report DTE speed in the CONNECT result code; and
                        that there is no setting of S95 that forces W1
                        to not produce the CARRIER and PROTOCOL result
                        codes.

                        The use of S95 represents an extension of the
                        function that the Wn command was intended to
                        perform. The version of the Wn command here with
                        S95=0 (default) maintains backwards
                        compatibility with previous V-Series products.
                        However, selecting W0 and setting S95 as
                        required permits you to tailor result codes
                        characteristics to their own requirements in a
                        compatible way.

			Refer to Chapter 5 for more information.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Xn Select Call Progress Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] X [suffix] [cmds] <CR> 

Suffix Values		0 through 4 

Factory Default	X4 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             This command enables tone detection options and
                        the associated result codes. Result codes
                        definitions are covered in Chapter 8.

                        X0 - Busy and dial tone detect disabled. Result
                        codes 0-4 enabled. Only CONNECT result code
                        allowed, and not the CONNECT XXXX result code.
                        Overrides Wn and S95.

                        X1 - Busy and dial tone detect disabled. Result
                        codes 0-5, all CONNECT XXXX, Wn and S95 enabled.

                        X2 - Busy detect disabled. Dial tone detect
                        enabled. Result codes 0-6, all CONNECT XXXX, Wn
                        and S95 enabled.

                        X3 - Busy detect enabled. Dial tone detect
                        disabled. Result codes 0-5, 7, all CONNECT XXXX,
                        Wn and S95 enabled.

                        X4 - Busy and dial tone detect enabled. Result
                        codes 0-7, all CONNECT XXXX, Wn and S95 enabled.

                        Note: The @ and W dial modifier result codes are
                        not affected by the Xn command in effect. The @
                        dial modifier enables result codes 8 (NO ANSWER)
                        and 7 (BUSY) each time it occurs in the dial
                        string. The W dial modifier enables result codes
                        6 (NO DIALTONE) and 7 (BUSY) each time it occurs
                        in the dial string.

Execution Time	1 ms maximum

Cross Reference	Commands - A, Dn, O, W 
			S-registers - S6, S7 
			Line signals - Busy, Dial tone, Carrier


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Yn Select Long Space Disconnect Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] Y[suffix] [cmds] <CR> 

Suffix Values		0, 1 

Factory Default	Y0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The Y command determines if the modem
                        disconnects a call upon receiving a long space
                        (1.6 sec break) signal from the distant end. If
                        Y1 is selected, the modem sends a 4-second break
                        (space) before going on hook when an H0 command
                        is issued or, if &D2 is selected, when DTR goes
                        off.

			Y0 - Disable long space disconnect 
			Y1 - Enable long space disconnect

                        Note: Y1 is only supported when the modem is
                        using &Q0 or &Q6 Async communication modes.
                        Long-space disconnect is not supported in any of
                        the error-control modes.

Execution Time 	1 ms maximum

Cross Reference	Commands - Hn, &Dn
			Register - S82 
			Hang up process


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Zn Perform Soft Reset

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] Z [suffix] <CR> 

Suffix Values		0 through 1 

Factory Default	N/A 

Stored by &Wn	N/A 
			
Displayed by &V	N/A 

Description             This command tells the modem to go on hook and
                        restore the selected stored profile. The modem
                        does not execute any commands that follow the Zn
                        command on the same command line.

			Z0 - Recall stored profile 0
			Z1 - Recall stored profile 1

                        Refer to the &Wn command for description of
                        which modem parameters are included in a stored
                        profile.

Execution Time 	2 seconds maximum

DTE Interface 
Lines Affected 	DSR, RLSD

LEDs Affected 		AA, CD, MR, OH, TR

Cross Reference	Commands - &Wn 
			DTE signals - RI 
			Straps - Dumb
			Relays - Auxiliary, Line, Phone


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&An - Select Originate/Answer Role For Autoanswer

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &A [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	&A0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             This command determines whether the modem
                        attempts to connect as the Originating or
                        Answering modem when Autoanswering calls. It may
                        be useful in call-back security techniques.

                        &A or &A0 - Use Answer direction when
                        Autoanswering. &A1 - Use Originate direction
                        when Autoanswering.

Execution Time 	2 ms maximum

DTE Interface 
Lines Affected 	None

LEDs Affected 		None

Cross Reference	Commands: A, D, S-0 
			DTE Signals: RI 
			Straps: NONE 
			Relays: NONE 
			Process: Answer, Handshake


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Cn - Select Data Carrier Detect Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &C [suffix] [cmds] <CR> 

Suffix Values		0 through 2 

Factory Default	&C0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             This command determines how the state of the
                        RLSD lead relates to the carrier from the
                        distant end. The command takes effect
                        immediately in both the Idle State and the
                        Online Command State.

                        The behavior patterns for RLSD depend on the
                        specific &Cn and &Qn commands in effect. Also,
                        RLSD patterns depend on whether online operation
                        is half- or full-duplex. Finally, if &Q5 is in
                        effect, RLSD behavior depends on whether S10=255
                        or S10<255. Refer to the tables below.

			Legend	Behaviors in the Tables
--------------------------------------------------------------------------
			A		The RLSD circuit is ON at all times.

                        B               The RLSD circuit is OFF in the
                                        Idle State, goes ON immediately
                                        after the CONNECT result code is
                                        issued, and goes OFF immediately
                                        after loss of carrier. If
                                        carrier goes on and stays on for
                                        the time set by S9, then RLSD
                                        goes ON again.

                        C               RLSD is OFF in Idle, tracks
                                        carrier in Online State.

                                        The RLSD circuit is OFF in the
                                        Idle State. It goes ON
                                        immediately after the CONNECT
                                        result code is issued, and goes
                                        OFF immediately after loss of
                                        remote carrier. If the remote
                                        carrier is restored, then RLSD
                                        goes ON (without the S9 delay).

                        D               RLSD is ON in Idle, RLSD tracks
                                        in Online.

                                        The RLSD circuit is normally ON
                                        in the Idle State, and it is ON
                                        while the remote carrier is
                                        present in the online State. In
                                        the online state, RLSD goes OFF
                                        immediately after loss of
                                        carrier. If carrier goes ON and
                                        stays on for the time set by S9,
                                        then RLSD goes ON again.

                                        If the hangup process begins
                                        while RLSD is OFF, then RLSD
                                        goes ON just prior to the issue
                                        of the NO CARRIER result code.

                        E               RLSD is OFF in Idle, ON in
                                        Online State.

                                        The RLSD circuit is OFF in the
                                        Idle State. It goes ON
                                        immediately after the CONNECT
                                        result code is issued, and it
                                        goes OFF when the modem begins
                                        the Hangup Process. RLSD does
                                        not track the presence of
                                        carrier.
			

                        F               RLSD is ON in Idle and tracks
                                        carrier in Online states,
                                        without S9 delay.

			RLSD Behaviors for Full Duplex Operation

			Command	&C0	&C1	&C2
                        --------------------------------------
			&Q0		A	B	D
			&Q1		B	B	B
			&Q2		B	B	B
			&Q3		B	B	B
			&Q4		B	B	B
			&Q5		A	E	A
			&Q6		A	B	D
			&Q5
			S10=255	A	B	D

                        The RLSD circuit is normally ON in the Idle
                        State, and it is ON while the remote carrier is
                        present in the Online State. It goes OFF
                        approximately 3 seconds after loss of remote
                        carrier. If the remote carrier is restored, then
                        RLSD goes ON again (regardless of S9). If the
                        Hangup Process is initiated by the DTE using DTR
                        or issuing ATH from the Online Command State,
                        then RLSD returns ON just prior to the modem
                        issuing the OK result code. The modem does not
                        begin the Hangup Process if S10=255.

Execution Time 	Maximum 1 ms

DTE Interface Lines
Affected		RLSD

Cross Reference	Commands - &Mn, &Qn 
			DTE signals - RLSD 
			Line signals - Carrier 
			LEDs - CD 
			Processes - Hang-up 
			S-registers - S9, S10


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Dn Select Data Terminal Ready Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &D [suffix] [cmds] <CR> 

Suffix Values		0 through 3 

Factory Default	&D0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The &Dn command affects how the modem responds
                        to the state of DTR and changes of DTR. The
                        effects of DTR states and changes are also
                        dependent upon the current communication mode
                        (&Qn or &Mn command). The test modes associated
                        with certain &Tn commands are only affected by
                        DTR changes when &D3 is in effect and are not
                        affected by &Qn or &Mn commands.

                        The TR LED shows the state of DTR except when
                        &D0 and &Q0 are in effect. Note that TR may have
                        special uses in certain test modes.

                        The following sections describe what DTR does
                        for each mode of modem operation.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Dumb, switched

The following chart describes what DTR does for Dumb switched mode of
operation.

Note: This feature is available in OPTIMA products.

		&D0 		&D1 		&D2 		&D3
-------------------------------------------------------------------------
V.14 (&Q0)	none		none		I, H		R
&Q1		C, H		C		I, C, H		C, R
&Q2		I, D, H		I, D, H		I, D, H		I, D, R
&Q3		I, O, H		I, O, H		I, O, H		I, O, R
AutoSync	H		none		I, H		R
AutoSync II	none		none		I, H		R
error control	none		none		I, S		R
ASB		none		none		I, S		R

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Smart AT, switched

The following chart describes what DTR does for smart AT switched mode
of operation.

		&D0 		&D1 		&D2 		&D3
-------------------------------------------------------------------------
V.14 (&Q0) 	none		E		I, H		R
&Q1 		C, H		C, E		I, C, H		C, R
&Q2		I, D, H		I, D, H		I, D, H		I, D, R
&Q3		I, O, H		I, O, H		I, O, H		I, O, R
AutoSync	H		E		I, H		R
AutoSync II	none		E		I, H		R
error control	none		E		I, S		R
ASB		none		E		I, S		R

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Timing of DTR Off-To-On Transitions

The off-to-on transition of the DTR lead function may initiate certain
functions as described below. The process initiated by the DTR off-to-on
transition is started no sooner than 5 ms and no later than 50 ms of the
DTR transition. S25 does not affect DTR off-to-on timing under any
conditions.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Timing of DTR On-To-Off Transitions

If the modem is on line, when a DTR on-to-off transition occurs, it must
last at least the time indicated by the value of S25 in order to be
valid; shorter durations are ignored by the modem. Thus, the processes
indicated above are started no sooner than the time indicated by the S25
register; and no later than 50 ms longer than the time in S25.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
DTR-Initiated Hard Reset (&D3 in effect)

When &D3 is in effect, the modem begins a hard reset process within 1 ms
of the DTR on-to-off event regardless of the modems current state and
regardless of the &Qn command in effect. S25 does not affect DTR
on-to-off timing when &D3 is in effect.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&F - Load Factory Default Profile

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &F [cmds] <CR> 

Suffix Values		none 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             This command tells the modem to copy the Factory
                        Default commands and S-register values into the
                        active profile. See the individual command and
                        register descriptions for default values.

                        The &F command is not valid in the Online
                        Command State.

Execution Time 	1.5 seconds max (this time needed for some new technologies).

Cross Reference	LEDs - TR


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Gn - Select Guard Tone Option

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &G [suffix] [cmds] <CR> 

Suffix Values		0, 2 

Factory Default	&G0 

Stored by &Wn	yes 

Displayed by &V	yes

Description             This command tells the modem which guard tone,
                        if any, to transmit while transmitting in the
                        high band (answer mode).
			
			&G0 - Guard tones disabled. 
			&G2 - 1800 Hz guard tone enabled. (V.22, V.22 bis only).
			
                        Note: Guard tone is transmitted only while the
                        modem is in the transmitting in the answer mode
                        and during the answer handshake.

Cross Reference 	Commands - A 
			Line signals - Guard tone 
			Answer process



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Kn - Select Flow Control Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &Kn [cmds] <CR> 

Suffix Values		0-6 

Factory Default	&K3 

Stored by &Wn	yes 

Displayed by &V	yes 


Description             If the parameter +FCLASS equals 0 or the modem
                        does not have any other +FCLASS values, the &Kn
                        command is used to select the local flow control
                        method. Local flow control is used only when
                        Online in a buffered mode (i.e., error-control
                        or buffered asynchronous).

			Flow control is always inhibited in command state. 

                        Flow control regulates the data stream between
                        the DTE and modem's DTE interface. Specific
                        functions depending on suffix value are as
                        follows:

			Command 	Meaning 
                        -------------------------------------------------
                        &K0             Disable all flow control. May be
                                        selected for use during buffered
                                        mode at the risk of overflowing
                                        the buffers and losing data.

			&K1		not used

			&K2 		not used

                        &K3             Enable bidirectional hardware
                                        flow control. Note that the
                                        DTE-to-modem cable must have the
                                        RTS/CTS wires. The &T19 command
                                        may be used by software to
                                        determine if the cable  is
                                        properly wired.

                        &K4             Enable bidirectional XON/XOFF
                                        flow control. These characters
                                        are not programmable and are
                                        fixed at DC1 and DC3,
                                        respectively. This method should
                                        not be used when XON/XOFF
                                        characters are sent as user data
                                        or as part of a file transfer
                                        protocol.

                        &K5             Enable Transparent XON/XOFF flow
                                        control. See detailed
                                        description below.

                        &K6             Enable Unidirectional XON/XOFF
                                        flow control. DC1 and DC3
                                        characters are sent to the DTE
                                        by the modem. DC1 and DC3 from
                                        the DTE to the modem are treated
                                        as user data and transmitted to
                                        the remote modem.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Transparent flow control

Transparent Flow Control provides a method of local flow control over
any DTE-DCE link which can pass an 8-bit data stream intact. The method
works by cloaking user data which might otherwise be interpreted as
Xon/Xoff by the DCE or DTE. The cloaked user data passes across the
local DTE-DCE connection and is then uncloaked and sent on in it's
original form. The cloaking process inserts an escape character and then
the user data character which has been XOR'd with $21. Decloaking
detects (and removes) the escape character and XOR's the next character
with $21 to restore the original user data. Characters $10, $11, $13,
$90, $91, and $93 are processed in this way.

The modem assumes the Xon state (Tx and Rx channels) when entering data
mode.

The modem interprets $13 or $93 from the DTE as Flow-Off, and $11 or $91
as Flow-On.

The modem uncloaks character pairs from the DTE that start with $10 or
$90, and sends the uncloaked versions to the distant end.

	Cloaked = $10 or $90 followed by $31, $30, $32, $B1, $B0, or $B2. 
	Uncloaked = $10, $11, $13, $90, $91, or $93.

The modem cloaks incoming data (data received from the line) as
indicated in the following table, according to the character format of
the last AT command.

Character Format 
Received Data 	7S1 		7M1 		7E1 		7O1
-------------------------------------------------------------------------------------------------------------
$10 becomes     $10$31          $90$31          $90$31          $10$31
$11             $10$30          $90$30          $90$30          $10$30
$13             $10$32          $90$32          $90$32          $10$32
$90             $10$B1          $90$B1          $90$B1          $10$B1
$91             $10$B0          $90$B0          $90$B0          $10$B0
$93             $10$B2          $90$B2          $90$B2          $10$B2

When it enters the data mode the modem assumes Xon state; that is, the
modem is free to send data to the DTE.

If transmit buffer goes above it's high water mark, then send Xoff.

If transmit buffer goes below it's low water mark, then send Xon.

The modem sends the following characters as Xon and Xoff to the DTE,
according to the character format of the last AT command.

Character Format 
Received Data 	7S1 	7M1 	7E1 	7O1
-----------------------------------------------------------------------
Xon = 		$11 	$91 	$11 	$91
Xoff = 		$13 	$93 	$13 	$93


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Pn - Select Pulse Dialing Parameters

--------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &P [suffix] [cmds] <CR> 

Suffix Values		0, 1 

Factory Default	N/A 

Stored by &Wn	yes 

Displayed by &V	no 


Description		The &Pn commands select the pulse dialing parameters.

                        *       &P0 - Normal (US) digit encoding and
                        make/break times.

                        The digit encoding and times associated with the
                        &P1 and &P2 commands are country specific.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Qn - Select Communications Mode Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &Q [suffix] [cmds] <CR> 

Suffix Values		0-6, 8-10 

Factory Default	&Q5 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The &Q command selects the communication mode
                        and is the extended version of the &M command.
                        The &Q command determines how the modem treats
                        transmitted and received data while in the
                        Online state (i.e., asynchronous, synchronous,
                        AutoSync, error-control, or buffered
                        asynchronous) and establishes certain call setup
                        procedures. Refer also to the &Cn, &Dn, and &Sn
                        commands in this chapter, and to the "Dialing,
                        Answer, and Hangup Processes" in Chapter 8.

                        The &Q2 and &Q3 commands are intended to enable
                        use of the modem by synchronous terminals. The
                        modem is configured by an asynchronous DTE,
                        while DTR is off. Then the synchronous terminal
                        is connected to the modem and calls are
                        controlled by DTR as described below. If the
                        value of S0 is not 0, and ringing is detected,
                        then after DTR goes on the modem answers the
                        call when the following conditions are
                        satisfied: (1) after the next ring and (2) when
                        the value of S1 equals or exceeds that of S0.

                        Note: Detection of ringing is forgotten by the
                        modem if ringing is not detected for 8 seconds.
                        Because of the intended use by synchronous
                        terminals, the A (answer) and D (dial) commands
                        are invalid when either &Q2 or &Q3 is selected.
                        The modem sends the ERROR result code if it
                        receives an A or D command (which would have to
                        occur while DTR is off).

                        All of the &Qn commands are valid in the
                        off-line command state; none are valid in the
                        Online Command State (return ERROR).

Command 	Online State 		Special Features (see NOTE below.) 
---------------------------------------------------------------------------
&Q0             Asynchronous            RLSD, DSR, and DTR behaviors are
                                        unique. (Refer to &Cn, &Sn and
                                        &Dn command definitions).

&Q1             Synchronous             In smart and switched dumb mode,
                                        DTR must be ON after CONNECT
                                        when a timer equal to S25
                                        expires. DTR is ignored in dumb
                                        leased-line mode. Available in
                                        OPTIMA products.

&Q2             Synchronous             DTR OFF-to-ON executes Dialing
                                        Process; D command invalid. DTR
                                        is ignored in dumb leased-line
                                        mode. Available in OPTIMA
                                        products.

                                        DTR ON-to-OFF executes Hangup
                                        Process (or the Reset Process if
                                        &D3 is in effect). The A command
                                        is invalid. Available in OPTIMA
                                        products.

&Q3             Synchronous             Dialing and Voice allowed from
                                        telephone when DTR is OFF. DTR
                                        is ignored in dumb leased-line
                                        mode.

                                        DTR OFF-to-ON executes the
                                        Handshaking Process (in orig);
                                        the D command is invalid. DTR
                                        ON-to-OFF executes Hangup
                                        Process (or the Reset Process if
                                        &D3 is in effect). The A command
                                        is invalid. Available in OPTIMA
                                        products.

&Q4             Hayes AutoSync          If AutoSync is in effect, DTR
                                        must be ON after CONNECT when
                                        check timer equal to S25
                                        expires; AutoSync II does not
                                        wait S25 time to DTR. Refer to
                                        the &Dn command for other DTR
                                        behaviors in &Q4 mode and refer
                                        to the AutoSync and AutoSync II
                                        specifications for other details
                                        of how S25 affects modem
                                        operation. Available in 28.8
                                        kbits/second OPTIMA products.

&Q5             Error-Control           This enables error-control.
                                        Depending upon various other
                                        commands, any one of several
                                        point-to-point protocols may be
                                        negotiated. After the modem
                                        handshake is complete, feature
                                        negotiation (see S48) is used to
                                        determine which protocol (see
                                        S46) is used for the
                                        communication session. If no
                                        common protocol is found between
                                        the local and remote modems, the
                                        fall back options (see S36) is
                                        used. These may include
                                        Automatic Speed Buffering (ASB),
                                        asynchronous mode or going
                                        on-hook.

                                        When in &Q5 mode, the DTE is
                                        always presented an asynchronous
                                        interface. When either
                                        error-control or ASB has been
                                        negotiated, flow control (&Kn)
                                        should not be disabled. The &Q1,
                                        &Q2, &Q3, and &Q4 commands
                                        return ERROR when issued while
                                        online during an error- control
                                        or ASB connection.

&Q6             Buffered                Automatic Speed Buffering is
                Asynchronous            useful for DTEs which cannot
                                        adjust to changing transmission
                                        speeds. This mode ensures the
                                        DTE-modem speed is set at a
                                        constant rate regardless of the
                                        line speed determined during the
                                        modem handshake. With the
                                        exception of flow control (&Kn)
                                        between the DTE and the attached
                                        modem, this mode is identical to
                                        the standard asynchronous mode
                                        (&Q0). ASB operation is also a
                                        fall back option (see S36) when
                                        the modem is set for
                                        error-control mode (&Q5). This
                                        feature is available in 28.8
                                        kbits/second OPTIMA modems.

                                        Because the DTE and DCE speeds
                                        are different in ASB, a 256-byte
                                        buffer is provided so that flow
                                        control does not occur on every
                                        character transmission. Some
                                        DTEs are sensitive to the buffer
                                        size so S-registers are provided
                                        to control the lower (S49) and
                                        upper (S50) boundaries.

&Q8             MNP Error-Control       The modem attempts to negotiate
                                        an MNP error-control link upon
                                        connection. The current setting
                                        in S46 bit 1 determines whether
                                        MNP (TM) 2-4 or MNP5 is
                                        negotiated. If S46 bit 1 is set
                                        to 1, MNP5 is preferred.

                                        If an MNP error-control protocol
                                        is not established, the modem
                                        falls- back according to the
                                        current setting in S36.

                                        If S36 bit 0 is 0 the modem
                                        hangs-up. If S36 bit 0 is 1 the
                                        modem connects according to S36
                                        bit 1.

                                        If S36 bit 1 is 0 the modem
                                        connects in Direct Async mode.
                                        If S36 bit 1 is 1 the modem
                                        connects in Buffered Async mode.

                                        The settings in S48 and S46
                                        (except bit 1) are ignored.

                                        If fallback to Buffered Async
                                        mode occurs, all data received
                                        during protocol negotiations are
                                        present in the received data
                                        buffer.

                                        The &Kn command setting
                                        determines the type of local
                                        flow-control while in
                                        error-control or buffered modes.

&Q9             V.42bis/MNP2-4          The modem attempts to negotiate
                                        a V.42bis error-control link
                                        upon connection. If V.42bis (or
                                        V.42) is not achieved, then
                                        MNP2-4 is attempted.
                                        Error-Control If neither
                                        error-control protocol is
                                        established, the modem
                                        falls-back according to the
                                        current setting in S36.

                                        If S36 bit 0 is 0 the modem
                                        hangs-up. If S36 bit 0 is 1 the
                                        modem connects according to S36
                                        bit 1.

                                        If S36 bit 1 is 0 the modem
                                        connects in Direct Async mode.
                                        If S36 bit 1 is 1 the modem
                                        connects in Buffered Async mode.

                                        The settings in S48 and S46 are
                                        ignored.

                                        If fall-back to Buffered Async
                                        mode occurs, all data received
                                        during protocol negotiations is
                                        present in the received data
                                        buffer.

                                        &Kn determines the type of local
                                        flow-control while in
                                        error-control or buffered modes.

                        Note: Refer to &Cn, &Sn, and &Dn, in this
                        chapter, and to the Handshaking, Dialing, and
                        Answering Processes in Chapter 8 for additional
                        information on interface lead behaviors.

                        Note: Refer to the &Kn and &Nn commands, to S36,
                        S37, S46, S48, and to Chapter 8 for additional
                        information on &Q5 and &Q6 operation.

DTE Interface 
Lines Affected		DSR, RLSD

Cross Reference 	Commands - &Cn, &Dn, &Mn, &Sn, &Kn, Nn
			S-registers - S36 Negotiation Fall Back 
			S37 Desired DCE Line Speed 
			S46 Protocol Selection 
			S48 Feature Negotiation Action 
			S49 ASB Buffer: Low Boundary 
			S50 ASB Buffer: High Boundary
			DTE signals - DSR, DTR, RLSD 
			LEDs - TR
			


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Rn - Select RTS/CTS Option

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &R [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	&R0 

Stored by &Wn	yes 

Displayed by &V	yes 


Description             The functions of Clear to Send (CTS) in
                        synchronous modes (&Q1, &Q2, and &Q3) are
                        determined by the &R command. The &Rn command
                        has no effect when the DTE Interface is
                        asynchronous. See also CTS and RTS in Chapter
                        11. Refer to the &Kn command for other RTS and
                        CTS functions.

			Note: This feature is available in OPTIMA products.

                        Note: When &Q4 is in effect (AutoSync
                        operation), RTS and CTS behaviors are unique.

			In Synchronous Modes (&Q1, &Q2, and &Q3):

                        &R0 - CTS tracks RTS while the modem is in
                        Online State and observes the RTS-to-CTS delay
                        determined by S26.

                        &R1 - CTS is ON while the modem is in the Online
                        State, and RTS is ignored.

DTE Interface 
Lines Affected 	CTS

Cross Reference 	Commands - &Mn, &Qn 
			S-registers - S26 
			DTE signals - RTS, CTS


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Sn - Select Data Set Ready Option

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &S [suffix] [cmds] <CR> 

Suffix Values		0 through 2 

Factory Default	&S0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The functions of DSR are determined by the &Sn
                        command in effect.

			When &Q0, &Q5, and &Q6 are in effect:

			&S0 - DSR circuit is always on.

                        &S1 - DSR is off in the Idle State and when in a
                        test mode. DSR circuit is turned ON at start of
                        the Handshaking Process. DSR is turned OFF when
                        Hangup Process is started.

                        &S2 - DSR is off in the Idle State and when in a
                        test mode. DSR circuit is turned ON at end of
                        handshake prior to issuing of the CONNECT result
                        code. DSR is turned OFF when Hangup Process is
                        started.

			When &Q1 to &Q4 are in effect:

                        &S0-1 - DSR is off in the Idle State. DSR
                        circuit is turned ON at start of the Handshaking
                        Process. DSR is turned OFF when Hangup Process
                        is started.

                        &S2 - DSR is off in the Idle State. DSR circuit
                        is turned ON at end of handshake prior to
                        issuing of the CONNECT result code. DSR is
                        turned OFF when Hangup Process is started.

DTE Interface 
Lines Affected 	DSR

Cross Reference 	Commands - &Mn, &Qn 
			DTE signals - DSR 
			Line signals - Answer tone


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T0 - Terminate Test In Process

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T0 <CR> 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 


Description             If a test is in process as a result of executing
                        an &Tn command, then the &T0 command causes that
                        test to be terminated. See specific &Tn
                        descriptions for termination actions. If no test
                        is in progress when the &T0 command is sent to
                        the modem, the modem takes no action except to
                        return the OK result code.

Execution Time 	2 ms maximum

LEDs Affected 		MR

Cross Reference 	Commands - &T1, &T3, &T6-&T8 
			S-registers - S18 
			DTE signals - DSR 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T1 - Initiate Local Analog Loopback

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T1 [suffix] <CR> 

Suffix Values		O or A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             The modem goes on hook and configures itself for
                        analog loopback (using low frequency band if no
                        suffix or O suffix, and high frequency band if A
                        suffix). DSR is turned off (if &S1 is in
                        effect), the analog loopback state is entered,
                        and the test timer is set to the value in S18. A
                        CONNECT result code is sent to the DTE, and the
                        test timer then begins its count down.

                        The test terminates when the test timer expires.
                        If S18 equals 0, then the test can only be
                        terminated by escaping from the online state
                        into the Online Command State and sending an
                        &T0, H0, or Zn command; or by a DTR on-to- off
                        transition under certain conditions. Refer to
                        Chapter 8.

                        While any command may be entered while the modem
                        is in this test state, the modem response is not
                        specified except for H0, &T0, and Zn, any of
                        which terminates the test.

                        Upon termination of the test, the modem reverts
                        to the Idle State. The command is only valid in
                        the Idle State.

Result Codes		CONNECT - when local analog loopback state is entered.

                        OK - after test is stopped by either the test
                        timer, the H0 command, or the &T0 command.

                        ERROR - if any other &Tn test is active (except
                        &T0) or if in the Online Command State.

Execution Time  Determined by test timer or until aborted by a command.

DTE Interface 
Lines Affected 	DSR

LEDs Affected 		MR flashes

Cross Reference 	Commands - &Sn, &T0, &T8, H0, Zn 
			S-registers - S18 
			DTE signals - DSR 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T3 - Perform Local Digital Loopback

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T3 [cmds] <CR> 

Suffix Values		N/A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             The modem must be in the Online Command State
                        when this command is issued. Otherwise an ERROR
                        result code occurs.

                        This command establishes a loopback of received
                        data, after demodulation, and sends it back to
                        the distant end. The modem is configured for
                        local digital loopback, DSR is turned off (if
                        &S1 is in effect), with the test timer is
                        started with the value in S18, and an OK result
                        code is sent to the DTE.

                        If S18 contains a 0, the test must be terminated
                        by a &T0, H0, or Zn command. The latter two
                        result in the modem going on hook. If S18 does
                        not contain 0, the test is terminated after the
                        number of seconds stored in S18.

                        The MR light flashes while the test is in
                        progress.

Result Codes		OK - after 2 s delay

                        ERROR - if any other self test is active (&T1,
                        &T6-&T8) or if in Idle State.

			OK - when test is terminated.

Execution Time 	Determined by test timer or until aborted by a command.

DTE Interface 
Lines Affected 	DSR

LEDs Affected 		MR flashes

Cross Reference	Commands - &Sn, &T0, H0, Zn 
			S-registers - S18 
			DTE signals - DSR 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T4 - Enable Granting Of RDL Requests

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T4 [cmds] <CR> 

Suffix Values		N/A 

Factory Default	&T4 (as opposed to &T5) 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             When in the Online State the modem honors a
                        remote digital loopback request from a distant
                        modem if it occurs. This results in an ERROR if
                        the command is given while any test is active
                        (&T1, &T3, &T6, &T7, or &T8).

Cross Reference	Commands - &T5


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T5 - Deny Granting Of RDL Requests

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T5 [cmds] <CR> 

Suffix Values		N/A 

Factory Default	&T4 (as opposed to &T5) 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             The modem does not respond to a remote digital
                        loopback request from a distant modem.

                        This command is not valid if given while any
                        test is active (&T1, &T3, &T6, &T7, or &T8).

Cross Reference	Commands - &T4


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T6 - Initiate Remote Digital Loopback

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T6 <CR> 

Suffix Values		N/A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             The command is only valid if the modem is in the
                        Online Command State, the modulation is one of
                        the Quadrature Amplitude Modulation (QAM) types
                        that support full-duplex transmission, and the
                        speed is the same in both directions. The
                        command is not valid for any FSK modulation
                        (e.g., V.21 and V.23).

                        Recommendations V.22 and V.22 bis specify how
                        remote digital loopback is initiated and ended
                        for V.22 and V.22 bis modems. Recommendation
                        V.54 specifies how the loopback is initiated and
                        ended on other types of full-duplex modems.

                        The modem sends the remote digital loopback
                        request signal to the distant modem. After the
                        RDL acknowledgment signal is received from the
                        distant modem, DSR is turned off (if &S1 is in
                        effect), the Online State is entered, a CONNECT
                        result code is sent to the DTE, and the test
                        timer is set to the value in S18. If the modem
                        does not receive the RDL acknowledgment signal
                        from the distant end in 3 seconds, it sends an
                        ERROR result code to the DTE and returns to the
                        Online Command State.

                        The modem sends the signal to release the remote
                        digital loopback when the test is terminated.
                        The test may be terminated by the H0, Zn, or &T0
                        command. The test also terminates when the test
                        timer expires (sending the modem to the Online
                        Command State) or carrier is lost (causing a NO
                        CARRIER result code and the modem to go on hook
                        in the Idle State).

Result Codes		CONNECT - when Online State is entered. 
			ERROR - if any test is active (&T1, &T3, &T6-&T8). 
			ERROR - if not in Online Command State. 
			ERROR - if command is invalid 
			ERROR - if the RDL signal is not acknowledged.

Execution Time  Command execution lasts for the time it takes to receive
                        the RDL acknowledgment signal plus the test
                        time.

DTE Interface 
Lines Affected		DSR

LEDs Affected		MR flashes

Cross Reference	Commands - &Sn, &T0, &T7, Hn, Zn 
			S-registers - S18 
			DTE signals - DSR 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T7 - Initiate RDL With Self Test

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T7 <CR> 

Suffix Values		N/A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A

Description             The command is only valid if the modem is in the
                        Online Command State, the modulation is one of
                        the QAM types that support full- duplex
                        transmission, and the speed is the same in both
                        directions. The command is not valid for any FSK
                        modulation (e.g., V.21 and V.23).

                        The modem sends the remote digital loopback
                        request signal to the distant end. After the RDL
                        acknowledgment signal is received from the
                        distant end, DSR is turned off (if &S1 is in
                        effect), the Online State is entered, an OK
                        result code is sent to the DTE, and the test
                        timer is set to the value in S18.

                        While the test is active the modem sends a test
                        message to the distant end and counts the errors
                        in the received (looped back) signal. The modem
                        stays in the Online Command State during the
                        test.

                        When the test is terminated (except by a loss of
                        carrier), the modem sends the release signal to
                        the distant end, as in &T6, and reports the
                        three- digit error count to the DTE. The
                        information text is followed by an OK result
                        code. See the V command for formats.

                        The test is terminated by loss of carrier, or an
                        H0, &T0, or Zn command, and by the timer timing
                        out (S18 time out).

Result Codes		OK - when command execution is started. 
			OK - after error count is sent to DTE. 
                        ERROR - if any other self test is active
                                (&T1, &T3, &T6-&T8)
			ERROR - if not in Online Command State. 
                        ERROR - if command is issued at other than 1200
                                or 2400 bit/second.
                        ERROR - if the RDL acknowledgment signal is not
                                received.

Execution Time  Command execution lasts for the time it takes to receive
                        the RDL acknowledgment signal, the test time,
                        and time to send error count to DTE.

DTE Interface 
Lines Affected		DSR

LEDs Affected		MR flashes

Cross Reference	Commands - &Sn, &T0, &T6, H0, Zn 
			S-registers - S18 
			DTE signals - DSR


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T8 - Local Loopback With Self Test

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T8 [suffix] <CR> 

Suffix Values		O or A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             The modem goes on hook and is configured for
                        analog loopback (low frequency band if none or O
                        suffix, high frequency band if A suffix). The
                        test timer is started at the time indicated by
                        S18, DSR is turned off (if &S1 is in effect), AL
                        Self-test state is entered, and an . OK result
                        code is sent to the DTE during the test the
                        modem sends a test message and counts errors in
                        the looped back signal.

                        The test is terminated when the timer times out
                        (S18) or the &T0, H0, or Zn command is issued.
                        When the test is terminated, the three-digit
                        error count is sent to the DTE. An OK result
                        code follows the error count.

Result Codes		OK - if AL Self-test state is entered. 
			OK - after error count is sent to DTE. 
                        ERROR - if any other test is active (&T1, &T3,
                        &T6, &T7), or if in the Online Command State.

Execution Time 	Duration of the test and time to send error count to DTE.

DTE Interface 
Lines Affected		DSR

LEDs Affected		MR flashes

Cross Reference	Commands - &Sn, &T0, &T1, H0, Zn 
			S-registers - S18 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&T19 - Perform RTS/CTS Cable Test

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &T19 <CR> 

Suffix Values		N/A 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             This command is used with suitable DTE software
                        to determine if the DTE cable used with a modem
                        supports the RS-232C signals RTS and CTS. This
                        procedure should be used by software before
                        RTS/CTS flow control (&K3) is used.

                        The modem takes the following action when this
                        command is issued:

                        1.      Turn OFF CTS (normally ON) and start a
                                500-ms timer.

			2.	Monitor RTS for ON and OFF states.

                        3.      After the 500 ms timeout or when both
                                level-high and level-low states of RTS
                                are detected, restore CTS to the ON
                                state and end the test.

                        4.      If both states of RTS were NOT detected
                                then return the ERROR result code;
                                otherwise issue OK result code.

                        The following steps describe what the DTE does
                        to perform an &T19 test.

			Step 1:		Send AT &T19 <CR>.
			
                        Step 2:         Wait for CTS to go off. If it
                                        goes off within 500 ms, then go
                                        to Step 3. Otherwise the test
                                        has failed.
			
			Step 3a:	Turn off RTS, wait 50 ms, turn on RTS. 
			
			Step 3b:	Repeat Step 3a, up to 6 times. 
			
                        Step 4:         If CTS goes on before the 6
                                        iterations are completed, then
                                        go to Step 5. Otherwise, the
                                        test has failed.
			
                        Step 5:         Wait for a result code from the
                                        modem. If the result code is OK,
                                        then the test has passed. If
                                        ERROR, the test has failed (the
                                        DTE-DCE cable is not suitable
                                        for RTS/CTS flow control).


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Un - Disable Trellis Coding

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &U [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	&U0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description		This command affects V.32 9600 bits/second only.

			*	&U and &U0 - Enable Trellis coding 
				(Factory Default) 
			*	&U1 - Disable Trellis coding
			


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&V - View Configuration Profiles

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &V [0] [cmds] <CR> 

Suffix Values		none 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             The active and stored profiles are displayed
                        (commands and S-register settings) along with
                        the stored telephone numbers. Inputs from the
                        DTE are ignored while the view information is
                        being sent to the DTE. The three-digit numbers
                        after each S-register number are decimal
                        representations of the S-register contents.

                        An example of the information text is displayed
                        below. This example resembles the &V info-text
                        when the Factory Default profile is loaded and
                        then stored into the stored profiles, and an
                        arbitrary number is stored in one of the stored
                        numbers. The <CR> and <LF> characters are not
                        symbolically represented in this example in
                        which V1 and Q1 are in effect. As usual, all
                        <CR> and <LF> characters are defined by
                        S-registers S3 and S4, respectively.


Cross Reference 	Commands - &Wn, &Zn=x, &Yn, &F.

&V Display Format       The &V format for modems providing Dynamic Phone
                        Storage is based on the following format:

       ACTIVE PROFILE: B1 B16 B30 B41 B60 B70 B75 B80 E0 L1 M1 N1
       Q0 T V1 W0 X4 Y0 &A0 &C1 &D2 &G0 &J0 &K3 &L0 &Q5 &R0
       &S0 &T4 &U0 &X0 &Y0 S00:000 S02:043 S03:013 S04:010 S05:008
       S06:002 S07:090 S08:002 S09:006 S10:014 S11:060 S12:050 S25:005 S26:001

       S36:007 S37:000 S38:020 S46:002 S48:007 S49:008 S50:016
       S108:002 S109:062 S110:002

       STORED PROFILE 0: B1 B16 B30 B41 B60 B70 B75 B80 E0 L1 M0 N1
       P Q0 V1 W0 X4 Y0 &A0 &C1 &D2 &G0 &J0 &K3 &L0 &Q5 &R0 &S0
       &T4 &U0 &X0 S00:000 S02:043 S06:002 S07:090 S08:002 S09:006 S10:014
       S11:060 S12:050 S25:005 S26:001 S36:001 S37:009 S38:020 S46:002 S48:007
       S49:008 S50:016 S108:002 S109:062 S110:002

       STORED PROFILE 1: B1 B16 B30 B41 B60 B70 B75 B80 E0 L1 M0 N1 P
       Q0 V1 W0 X4 Y0 &A0 &C1 &D2 &G0 &J0 &K3 &L0 &Q5 &R0 &S0
       &T4 &U0 &X0 S00:000 S02:043 S06:002 S07:090 S08:002 S09:006 S10:014
       S11:060 S12:050 S25:005 S26:001 S36:001 S37:009 S38:020 S46:002
       S48:007 S49:008 S50:016 S108:002 S109:062 S110:002

       TELEPHONE NUMBERS:
       &Z0=9,7296558
       &Z1=
       &Z2=
       &Z3=

       OK

			where: 
                        a.      The selection of commands and registers
                                are determined on a product by product
                                basis.

			b.	Four groups of information to be displayed are: 
			
			*	Active Profile
			*	Stored Profile 0
			*	Stored Profile 1
			*	Stored Phone Numbers.
			
                        c.      In the first three groups, selected
                                commands are displayed in alphanumeric
                                order with one space between each
                                starting at the next available display
                                position from the following list: 17, or
                                21. Then selected S-registers are
                                displayed in numeric order each starting
                                at the next available display position
                                from the following list: 1, 9, 17, 25,
                                33, 41, 49, 57, 65, or 73.

                        d.      The S-register entries are in the format
                                Saa:vvv where;

				aa = the address of the register in decimal.

				vvv = the contents of the register in decimal.

                        e.      With the intent of packing as many
                                commands and registers into the display
                                as practical, the group headers,
                                commands, and registers follow each
                                other on the same lines where possible.
                                Further, it is permissible to use the
                                currently blank line between groups to
                                expand the group displays. If this were
                                done, there are no blank lines within
                                the info-text area of the &V display.
			
                        f.      The phone number group has been modified
                                to permit variable length phone numbers,
                                provide an easy to read display, and
                                minimize the number of display lines
                                used. The traditional header line is
                                removed, and in its place, each phone
                                number begins with a mini-header
                                consisting of the &Zn= command that
                                would be used to program that memory.
                                Each phone number begins on a new line
                                for readability. If a phone number has
                                more than 75 characters, a <CR> <LF>
                                followed by 4 spaces is sent before the
                                76th character of the rest of that
                                string.
			
                        g.      Only character positions 1-79 are used
                                horizontally. It is desirable to keep
                                the total number of lines used in the &V
                                display and the associated verbose
                                result code to 23 lines or less. This
                                prevents the top line from scrolling off
                                the top of terminal screens which have a
                                23 line limit.
			
                        h.      There is always one blank line between
                                the body of the &V display and the
                                verbose OK result code.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Wn - Store Active Profile

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &W [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 


Description             Certain commands and S-register contents are
                        copied into one of the nonvolatile Stored
                        Profiles by this command.

                        *       &W0 - Store the Active Profile into
                                      Stored Profile #0.
                        *       &W1 - Store the Active Profile into
                                      Stored Profile #1.

			The following items are stored:

			*	current AT Speed and parity
			*	current contents of certain S-registers.
			*	current states of certain commands.

                        See the S-register and command definitions to
                        determine which are stored by the &W command.

Execution Time	2 sec maximum plus time to transmit to DTE.

Cross Reference 	Commands - Zn, &V, &Yn 
			Processes - Hard Reset


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Xn - Select Sync Transmit Clock Source

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &X [suffix] [cmds] <CR> 

Suffix Values		0 through 2 

Factory Default	&X0 

Stored by &Wn	yes 

Displayed by &V	yes 

Description             This command determines how the DTE transmit
                        clock is generated while the modem is in the
                        synchronous mode.

			Note: This feature is available in OPTIMA products.

                        *       &X0 - The modem generates the transmit
                                clock and applies it to pin 15 (RS-232).

                        *       &X1 - The DTE generates the transmit
                                clock on pin 24 (RS-232) and the modem
                                applies this clock to pin 15 (RS-232).

                        *       &X2 - The modem derives the transmit
                                clock from the receive carrier signal
                                and applies it to pin 15 (RS-232).

DTE Interface 
Lines Affected		Clock leads (Pins 15, 17, & 24)

Cross Reference 	Commands - &Mn, &Qn 
			DTE signals - SCTE, SCT, SCR


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Yn - Select Stored Profile For Hard Reset

-----------------------------------------------------------------------------------------------------------------------------
Command Line 
Format		AT [cmds] &Y [suffix] [cmds] <CR> 

Suffix Values		0 through 1 

Factory Default	none

Stored by &Wn	no

Displayed by &V	yes 

Description             This command selects which stored profile is
                        copied into the active profile subsequent to a
                        hard reset (including power-up). The &Yn command
                        execution is nonvolatile, it is stored in
                        nonvolatile memory at the time that the &Yn
                        command is executed, and it is not stored by the
                        &Wn command. It is not affected by the &F
                        command, but new modems have had &Y0 selected by
                        the factory when shipped.

			*	&Y0 - Select Stored Profile #0 on Hard Reset. 
			*	&Y1 - Select Stored Profile #1 on Hard Reset.


Cross Reference 	Commands - Zn 
			Processes - Hard Reset


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
&Zn= - Store Telephone Number

Description             Used to store up to four dialing strings. These
                        stored dial strings are non-volatile (survive
                        power outages). Refer to the D command and to
                        the Dial Modifiers to determine valid dial
                        strings. If no dial string is used, then the
                        referenced stored number is cleared.

&Z syntax 		AT [cmds] &Z[[n]=] [dial_string]<CR>

where: 
                        a.      All characters that follow the &Zn=
                                command until the carriage return are
                                treated as dial_string entry.

                        b.      If the = token is present in the next
                                position after the &Z, then string 0 is
                                assumed.

                        c.      If the = token is present in the second
                                position after the &Z, address then the
                                first position after the &Z must be a
                                valid phone string (n). Valid values for
                                n are 0, 1, 2, or 3. If the character is
                                not a valid (n), then an ERROR results.

                        d.      If no = token is found in either the
                                first or second position after the &Z ,
                                then location zero is assumed, and the
                                remainder of the command line is the
                                candidate dial string for location 0.

                        e.      If the dial_string is missing, the
                                memory is cleared.

                        f.      The following characters are storable in
                                dial_strings;

				0123456789ABCD#*,"$TPRW@!; 

			g.	Other characters are ignored, not stored.

                                Further, disposition of characters
                                following a ; (semicolon) dial are not
                                modifier in an &Z entry are not
                                specified. If such characters stored,
                                they are ignored.

                        h.      Lower case letters entered are converted
                                into upper case for storage.

                        i.      Available Space is defined as the
                                storage area being used by the
                                pre-existing string in the target
                                location, plus any phone number space
                                not currently in use by the other three
                                phone strings. It is assumed that the
                                present phone number space consisting of
                                4x36=144 characters continues to be the
                                total size of the non-volatile memory
                                phone number area.

                        j.      If the string of "storable" characters
                                does not fit into the available space,
                                then no change to the pre-existing
                                stored string occurs. The command
                                produces ERROR.

                                Example: assume String 0 uses 20
                                characters; String 1 uses 30 characters;
                                String 2 uses 50 characters; and String
                                3 uses no characters. There are 44
                                characters free. Attempts to store 64
                                storable characters in String 0 would
                                produce an OK result code, but 65
                                characters would produce an ERROR result
                                code.

Suffix Values		0 through 3 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	yes 

Execution Time 	500 ms maximum 

Cross Reference	Commands: S=n, &V


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
, <comma> Perform Pause

-------------------------------------------------------------------------
Command Line 
Format		AT [cmds] , [cmds] <CR> 

Suffix Values		none 

Factory Default	N/A 

Stored by &Wn	N/A 

Displayed by &V	N/A 

Description             Pause for the amount of time specified by S8 (in
                        seconds) before processing the next character in
                        the command string. This command is also a dial
                        modifier.

Execution Time 	S8 seconds

Cross Reference 	Commands - Dn, comma dial modifier 
			S-registers - S8


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
= - Write To An S-Register

This is an abbreviated form of the Sn=x command. Refer to the Sn=
command for a complete description.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
? - Read An S-Register

This is an abbreviated form of the Sn? command. Refer to the Sn? command
for a complete description.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
P - Select Pulse Dialing

-----------------------------------------------------------------------------------------------------------------------------
Dial String Format 	[digits and modifiers] P [digits and modifiers]

Factory Default	P (as opposed to D) 

Stored by &Wn	yes

Note: P may also be used as a command. Whether P is executed as a
command or as a dial modifier, the effect is the same. The current
choice of dialing method (P or T) may be stored in Profiles. As a Dial
Modifier, P may also be a part of a dial string that is stored in one of
the four stored numbers. Refer to the &Zn= command.

Displayed by &V	yes

Description             This dial modifier instructs the modem to use
                        pulse dialing. Dialed digits are pulse-dialed in
                        subsequent digits of the current dial string and
                        in all future dial strings until a T command or
                        dial modifier is executed.
			
Execution Time 	1 ms maximum

Cross Reference 	Commands - Dn, T, P

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
T - Tone

-------------------------------------------------------------------------
Dial String Format 	[digits and modifiers] T [digits and modifiers]

Stored by &Wn	yes

Note: T may also be used as a command. Whether T is executed as a
command or as a dial modifier, the effect is the same. The current
choice of dialing method (P or T) may be stored in Profiles. As a Dial
Modifier, T may also be a part of a dial string that is stored in one of
the four stored numbers. Refer to the &Zn command.

Displayed by &V	yes

Stored by &Wn	yes

Description             The T dial modifier instructs the modem to send
                        DTMF tones while dialing. Dialed digits are tone
                        dialed until a P command or P dial modifier is
                        selected.
			
Execution Time 	1 ms maximum 

Cross Reference 	Commands - Dn, P, T command


=========================================================================
Chapter 5
Result Codes


*************************************************************************
Basic Result Codes

Short Form	Result Code 	MEANING 
-------------------------------------------------------------------------
-----
0               OK              Acknowledges entry into either the idle
                                state or the Online Command State after
                                successful execution of a command line,
                                Hayes Patented, or "DTR-escape". There
                                may be instances for which the modem
                                does not actually execute a command but
                                returns OK anyway. This is done to
                                provide compatibility with some
                                communication software.

1               CONNECT         A connection has been established at
                                unstated line and DTE speeds if the X0
                                command is in effect; a connection has
                                been established at a line and DTE speed
                                of 0 to 300 bit/second if X0 is not in
                                effect.

2               RING            Ringing voltage on and off has been
                                detected.

3		NO CARRIER	Failure to connect or loss of carrier.

4               ERROR           Command not recognized. Command line too
                                long. Response to I command, incorrect
                                check sum. Command issued at 110 or 300
                                bit/second and a synchronous mode in
                                effect.

5               CONNECT 1200    A connection has been established and
                                the DTE should change its port speed to
                                1200 bit/second.

6               NO DIALTONE     Dial tone detection was attempted but
                                not found within the time out period.
                                Blacklisting may also cause the modem to
                                detect no dial tone.

7		BUSY 		A busy signal has been detected.

8               NO ANSWER       The @ Wait For Quiet Answer dial
                                modifier was executed, and 5 seconds of
                                silence was not detected.

10              CONNECT 2400    A connection has been established and
                                the DTE should change its port speed to
                                2400 bit/second.


**************************************************************************************************
Extended Result Codes

Extended Result Codes
Numeric 	Verbose 		Numeric 	Verbose 
--------------------------------------------------------------------------------------------------
11              CONNECT 4800            56              CARRIER 38400
12              CONNECT 9600            57              CARRIER 56000
13              CONNECT 14400           58              CARRIER 57600
14              CONNECT 19200           59              CARRIER 64000
15              CONNECT 28800           60              CONNECT 21600
16 		TIMEOUT 		61		CONNECT 20800 
17              CONNECT 56000           62              CONNECT 41600
18              CONNECT 57600           63              CONNECT 51200
19              CONNECT 64000           64              CONNECT 62400
20 		CONNECT 0600/75 	65		CONNECT 230400 
21 		CONNECT 75/0600 	66		COMPRESSION: CLASS 
22 		CONNECT 1200/75 	67		COMPRESSION: V.42BIS 
23 		CONNECT 75/1200 	68		Not applicable
24              CONNECT 7200            69              COMPRESSION: NONE
25              CONNECT 12000           70              PROTOCOL: NONE
26              CONNECT 16800           71              Not applicable
27              CALL WAITING            72              Not applicable
28              CONNECT 38400           73              Not applicable
29              CONNECT 24000           74              Not applicable
30              CONNECT 33600           75              Not applicable
31              CONNECT 115200          76              Not applicable
32              CONNECT 48000           77              PROTOCOL: LAP-M
33 		FAX 			78		Not applicable
34              CONNECT 26400           79              Not applicable
35 		DATA 			80 		PROTOCOL: ALT 
36              CARRIER 26400           81              Not applicable
37              CARRIER 24000           82              Not applicable
38              CARRIER 21600           83              Not applicable
39              CARRIER 48000           84              Not applicable
40 		CARRIER 300 		85		Not applicable
41 		CARRIER 600 		86		PROTOCOL: FAX 
42              CARRIER 600/75          87              Not applicable
43              CARRIER 75/600          88              Not applicable
44 		CARRIER 1200/75 	89		Not applicable
45 		CARRIER 75/1200 	90		Not applicable
46              CARRIER 1200            91              Not applicable
47              CARRIER 2400            92              Not applicable
48              CARRIER 4800            93              Not applicable
49              CARRIER 7200            94              Not applicable
50              CARRIER 9600            95              Not applicable
51              CARRIER 12000           96              Not applicable
52              CARRIER 14400           97              Not applicable
53              CARRIER 16800           98              Not applicable
54              CARRIER 19200           99              Not applicable
55 		CARRIER 28800 		


=========================================================================
Chapter 6
S-registers


*************************************************************************
Introduction

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Scope

S-register commands are provided to allow the DTE to read or write
certain modem parameters. This Chapter defines S-register functions, and
syntax and evaluation rules.

The modem does not support any S-registers that are not identified in
the Chapter. The names of unidentified registers should be considered
reserved.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Command Lines

The valid forms for S-register commands are:

Command Line Form 		Note 
-------------------------------------------------------------------------------------------------------
AT Sn=<value> <CR> 		value is stored in Sn 
AT Sn= <CR> 			value 0 is assumed 
AT S=<value> <CR> 		S0 is assumed 
AT S= <CR> 			S0 and value 0 are assumed 
AT =<value> <CR> 		last Sn is assumed 
AT = <CR> 			last Sn and value 0 are assumed 
AT Sn? <CR> 			the value of Sn is sent to DTE 
AT ? <CR> 			last Sn is assumed AT S? <CR> S0 is assumed

Note: The symbols S, ?, and = are all separate commands. The number n is
called the address.

Other commands may precede or follow S-register commands, subject to the
restrictions of the other commands.

In command lines, the numbers n and <value> are expressed as ASCII-coded
decimal digits. The number of digits used to express n and <value> is
limited only by the length of the resulting command line. Leading zeros
in an S-register address or value are echoed but ignored. Thus S00012 is
the same as S12 and S10=000025 is the same as S10=25. Modems accept
values up to 255 and may accept larger values.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Default Value

The phrase default value, in this Chapter, means the value that is
established by the &F command. The value left in a register after
factory testing may not be the default value.


**************************************************************************************************
Types

A value-mapped register is one whose value is interpreted as the value
of a modem parameter. Such registers have ranges of valid values.

A bit-mapped register is one whose value is interpreted as a set of bits
whose binary values separately control modem parameters. Bit 0 is the
least significant bit.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Behavior Of Unimplemented S-registers

The Sn? command to an unimplemented register is not regarded as
erroneous, and the modem does not exit the command line because of it.
The info-text for this command is always 000 with normal <CR> and <LF>
characters.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Classifications Of S-registers

S-registers are classified in several ways.

a.      Valid registers have addresses that are between zero and some
        upper limit (the upper limit for most modems is 255). Negative
        addresses are invalid.

        The modem remembers the last used address. After power-up or
        reset, the last used address is 0. Attempts to point to an
        invalid address do not change the last used address.

b.      A register to which RAM space has been assigned is said to
        exist. Only registers whose addresses are valid exist.

c.      Implemented registers are registers that exist and perform a
        defined modem function, and these definitions are presented.

d.      Unimplemented registers are those that exist but serve no
        function. A modem may contain some unimplemented registers. Some
        are mandatory for backward compatibility. Others are included as
        a convenience in the firmware design.

e.      Value-Mapped registers are those whose values represent modem
        parameters.

f.      Bit-Mapped registers are those whose individual bit values
        represent modem parameters but the total value does not.

g.      Read-Only registers are those whose values may be read but not
        altered by the = command. These registers are normally used to
        present the current status or outcome of an event or process.

h.      Non-volatile registers are those whose values remain after a
        loss of power. Non-volatile registers are not stored by the &Wn
        command.

i.      Stored Registers are those which may be copied into a stored
        profile by the &Wn command.


**************************************************************************************************
Value Evaluation Rules

Value evaluation rules define the outcome of the write operations
performed by the = command to registers that exist.

Value mapped

Value-mapped register values have bounds. Write commands with values
that are within the bounds are accepted. If an attempt is made to write
a value that is outside of the allowed range, then the outcome is (1)
below unless (2) is specified in the register description.

1.      The bound value that is closest to the entered value is written
        and an OK result code returned.

2.      The register value is not changed and the ERROR result code is
        returned.

Bit mapped

The bits to be written to a bit-mapped register are determined from the
binary number equivalent to the decimal value entered in a write
command. Bits indicated by the value that are defined is written. Unused
bits indicated by the value are ignored and their values set to 0. For
example, if the value 10 is given in a write command (binary 1010) to a
register for which only bits 0, 1, and 2 are used, then bits 0, 1, and 2
are set to 0, 1, and 0, respectively, and all other bits set to 0.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Summary Of S-register Behaviors

The following figure illustrates the reading and writing rules. The
illustration refers to numbers 1-6 in the S-register Commands, refer to
the chart following the illustration for definitions of the S-register
commands for the six possible S-register values.

S-register Rules



S-register Commands
S[n][? [ =[<value>    Pointer/Result Code   Read/Result Code  Write/Result Code
-------------------------------------------------------------------------------
Valid Address (no)      Don't Point,ERROR           N/A               N/A
Exist (no)              Point, OK             Say 000, OK     Don't Write, OK
Implemented (no)        Point, OK             Say 000, OK     Don't Write, OK
Read Only (no)          Point, OK            Read xxx, OK     Don't Write, OK
Bit Mapped type         Point, OK            Read xxx, OK     Write bits, OK
Value Mapped type       Point, OK            Read xxx, OK     Write clamps, OK


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S0 - Ring After Which To Answer

Description             Establishes the number of the rings after which
                        the modem answers (first, second, third, etc.).
                        A value of from 1 to 255 places the modem in
                        auto-answer mode. Setting S0 to 0 disables
                        auto-answer mode. The AA LED on the front panel
                        is illuminated when S0 contains a number larger
                        than zero.

Type			value 

Value range 		0 to 255, Default value: 0 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S1 - Ring Count

-----------------------------------------------------------------------------------------------------------------------------
Description             S1 is incremented each time the modem detects a
                        ring signal on the telephone line, while the
                        command process is not active, and is cleared if
                        no rings occur over any eight-second interval.

Type			value 

Value range 		0 to 255, Default value: 0 

Stored by &Wn	no 

Displayed by &V	no 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S2 - Hayes Escape Character

-----------------------------------------------------------------------------------------------------------------------------
Description             S2 contains the decimal value of the ASCII
                        character used for the escape character. The
                        default value corresponds to an ASCII "+". See
                        the "Hayes Improved Escape Sequence  with guard
                        time " in Chapter 8. A disables the Hayes
                        Patented Escape Process with guard time. That
                        is, no escape value over 127 character is
                        recognized. Values for S2 are stored in
                        nonvolatile memory profiles by the &Wn commands.

Type 			value 

Value range 		0 to 255, Default value: 43 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S3 - Carriage Return Character

-----------------------------------------------------------------------------------------------------------------------------
Description             S3 holds the decimal value of the ASCII
                        character used to represent <CR>. The default
                        value represents an ASCII CR.

Type			value 

Value range 		0 to 127, Default value: 13

Stored by &Wn	no 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S4 - Line Feed Character

-----------------------------------------------------------------------------------------------------------------------------
Description             S4 holds the decimal value of the ASCII
                        character used to represent <LF>. The default
                        value represents an ASCII LF.

Type			value
 
Value range 		0 to 127, Default value: 10 

Stored by &Wn	no 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S5 - Backspace Character

-----------------------------------------------------------------------------------------------------------------------------
Description             S5 holds the decimal value of the ASCII
                        character used for <BS>. The default value
                        represents an ASCII BS.

Type			value 

Value range 		0 to 32, 127 Default value: 8

Stored by &Wn	no 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S6 - Wait Before Blind Dialing

-----------------------------------------------------------------------------------------------------------------------------
Description             The value in S6 determines how long the modem
                        waits after going off hook before blind dialing.
                        See the D and Xn commands in Chapter 4.

Type			value (seconds)

Value range 		2 to 255, Default value: 2 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S7 - Wait For Carrier

-----------------------------------------------------------------------------------------------------------------------------
Description             The value in S7 sets the time limit for the
                        following events.

			*	wait for silent answer (@ dial modifier) 
			*	wait for dial tone (W dial modifier) 
                        *       wait for carrier completion of
                                handshaking timeout.

                        See also D command, @ dial modifier, W dial
                        modifier, in Chapter 4 plus "Dialing Process",
                        and "Handshaking Process" in Chapter 8.

Type			value (seconds)

Value range 		1 to 255, Default value: 50 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S8 - Pause Time For Comma

-----------------------------------------------------------------------------------------------------------------------------
Description             Establishes the duration of the pause when a
                        comma (,) is encountered in a command line or
                        dial string.

Type			value (seconds) 

Value range 		0 to 255, Default value: 2 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S9 - Carrier Recovery Time

-----------------------------------------------------------------------------------------------------------------------------
Description             The number of tenths of a second in S9 is the
                        time delay between a return of carrier, in the
                        online state, and the acceptance of the carrier.
                        Carrier is considered to have been detected S9
                        time after the bit pump reports carrier present.
                        See also S10.

			See "Carrier Detection" in Chapter 8.

			Note: Answer tone and carrier detection timing during the handshake 
			process is not timed by S9.

Type			value (deciseconds) 

Value range 		1 to 255, Default value: 6 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S10 - Lost Carrier Hang Up Delay

-----------------------------------------------------------------------------------------------------------------------------
Description             The time specified in S10 is the length of time
                        in tenths of seconds that a carrier may remain
                        undetected, in the online state, before the
                        modem starts the hang-up process. If carrier is
                        lost and its return is not reported by the bit
                        pump for a time equal to the difference in times
                        indicated by the values of S9 and S10, then the
                        modem should start the hang-up process. If
                        carrier does return before the time limit, the
                        carrier must persist for the S9 time before the
                        modem will consider carrier to be on.
			
                        If S10 is set to 255, the modem does not hang up
                        when carrier is lost (and the modem continues to
                        send its modulated carrier). The modem may
                        attempt a retrain, but may not hang-up.
			
			See "Carrier Detection" in the Chapter 8.

Type			value 

Value range 		1 to 255, Default value: 14

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S11 - DTMF Dialing Speed

-----------------------------------------------------------------------------------------------------------------------------
Description             The time specified by S11 is the duration of a
                        DTMF tone pulse and the time between consecutive
                        pulses.

Type			value (milliseconds) 

Value range 		50 to 255, Default value: 95 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S12 Hayes Escape Guard Time

-----------------------------------------------------------------------------------------------------------------------------
Description             The time specified by S12 is the guard time used
                        by the Hayes Patented Escape Process with guard
                        time. See Chapter 8.

Type			value (1/50 second) 

Value range 		0 to 255, Default value: 50 

Stored by &Wn	yes 

Displayed by &V	yes 



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S16 - Test in Progress

-----------------------------------------------------------------------------------------------------------------------------
Description     The bits of this S-register indicate which tests are in
                progress.

Type			bit mapped, read only 
Value range 		0 to 127, Default value: 0

Stored by &Wn	no 

Displayed by &V	no

Bit Map
			Bit 	Meaning 
			---------------------------------------------------------------------------
			0 	Local analog loopback is enabled 
			1	Reserved 
			2	Local digital loopback is enabled 
			3	Remote digital loopback (at this end) enabled 
			4 	Remote digital loopback enabled 
			5 	Remote digital loopback with self test enabled 
			6 	Local analog loopback with self test enabled 
			7 	Reserved


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S18 - Modem Test Timer

-----------------------------------------------------------------------------------------------------------------------------
Description             Establishes duration of modem's diagnostic
                        tests. When a test is active for a length of
                        time equal to the value chosen for this
                        register, the modem automatically cancels the
                        test. A setting of zero (0) disables the test
                        time and allows a test to run indefinitely.

Type			value 

Value range 		0 to 255, Default value: 0

Stored by &Wn	yes 

Displayed by &V	no 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S19 - AutoSync Options

-----------------------------------------------------------------------------------------------------------------------------
Description		Defines options for Hayes AutoSync operation.

			Note: NRZI coding is only valid in HDLC mode.

                        Note: This S-register is available in OPTIMA
                        products.

Type			bit mapped, Default value: 0 

Stored by &Wn	no 

Displayed by &V	no 

Bit Map

			Bit 	Meaning 
			-------------------------------------------------------------------------
			0 	reserved
			1	0 selects BSC (default) 
				1 selects HDLC
			2	0 disables HDLC address detection (default) 
				1 enables HDLC address detection
			3	0 selects NRZI bit encoding (default) 
				1 selects NRZ bit encoding
			4 	0 selects mark idle (default) 
				1 selects flag or sync idle
			5 	0 selects AutoSync (default) 
				1 selects AutoSync II
			6 	reserved
			7	reserved


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S25 - Detect DTR Change

-------------------------------------------------------------------------
Description             If &Q1 is in effect, then S25 is the delay in
                        seconds after a connection has been made (and
                        the modem has gone to the online state), but
                        before the modem examines the DTR lead. This
                        delay allows you sufficient time to disconnect
                        the modem from an asynchronous terminal to
                        attach the modem to a synchronous terminal,
                        without forcing the modem back to the command
                        mode.

                        If &Q4 is in effect and bit 5 of S19 is 0
                        (AutoSync selected), then S25 sets the time in
                        seconds that the modem pauses after a connection
                        is established. This gives the DTE time to reset
                        its serial port to 9600 bits/second, 8 data
                        bits, mark parity, and one stop bit. This
                        feature is not used with AutoSync II operation.

                        For any &Qn command in effect, if in the
                        dialing, handshaking, online, or Online Command
                        State, DTR excursions from ON to OFF that last
                        less than the time specified by S25, in 0.01 sec
                        increments, are ignored by the modem. (If &D3 is
                        in effect, it overrides the effect of S25 and
                        results in instantaneous effect of DTR ON to
                        OFF).

                        The value of S25 has no effect on recognition of
                        ON-to-OFF transitions of DTR while the modem is
                        in the idle state.

Type			value (seconds or centiseconds) 

Value range 		0 to 255, Default value: 5 

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S26 - RTS To CTS Delay Interval

-----------------------------------------------------------------------------------------------------------------------------
Description             If &R0 is selected, the modem waits the length
                        of time specified by S26 in 10 ms increments
                        before turning on CTS in response to an
                        off-to-on change in RTS. See &R command in
                        Chapter 4.

                        Note: This S-register is available in OPTIMA
                        products.

Type			value (centiseconds) 

Value range 		0 to 255, Default value: 1

Stored by &Wn	yes 

Displayed by &V	yes 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S30 - Inactivity Timeout

-----------------------------------------------------------------------------------------------------------------------------
Description             The modem enters the hang-up process whenever
                        both the DTE and the DCE are inactive for a time
                        greater than the value contained in this
                        register, in tens of seconds. This function is
                        disabled when the register contains the value 0,
                        which is the default.

			This register is ignored in leased-line operation. 

Type			value (decaseconds)

Value range 		0 to 255, Default value: 0 

Stored by &Wn	yes 

Displayed by &V	no 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S31 - XON Character

-----------------------------------------------------------------------------------------------------------------------------
Description             This register defines which ASCII character is
                        used as the XON character in software
                        (start/stop) flow control. This register does
                        not affect the character in used in transparent
                        flow control.

Type			value 

Value range 		0-255, Default value: 17 (DC1) 

Stored by &Wn	yes

Displayed by &V	no


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S32 - XOFF Character

-----------------------------------------------------------------------------------------------------------------------------
Description             This register defines which ASCII character is
                        used as the XOFF character in software
                        (start/stop) flow control. This register does
                        not affect the character used in transparent
                        flow control.

Type			value 

Value range 		0-255, Default value: 19 (DC3) 

Stored by &Wn	yes

Displayed by &V	no



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S36 - Negotiation Failure Treatment

-----------------------------------------------------------------------------------------------------------------------------
Description             When an error-control connection cannot be
                        negotiated between the two modems, this register
                        indicates which operating mode the modem will
                        use. Note that if negotiation is disabled
                        (S48=128), these fallback options are initiated
                        immediately.

                        In products supporting MNP 5, which negotiated
                        class is determined by the setting in S46. Bit 2
                        of that register is the master compression bit
                        which if on (values 2, 3, 138) will result in
                        MNP Class 5 negotiation and if off (values 0, 1,
                        136) results in MNP Class 4 negotiation.

Type			bit mapped

Value range 		0-7, Default value: 7

Stored by &Wn	yes 

Displayed by &V	yes

Bit map	
			Bit 	Meaning 
			----------------------------------------------------------------
			0 	0=hangup, 
				1=fall back according to bit 1 
			1	0=direct async, 
				1=first try ASB 
			2	0=do not try MNP, 
				1=first try MNP then according to bits 0 and 1. 
			3	reserved 
			4 	reserved 
			5 	reserved 
			6 	reserved 
			7 	reserved 


Value meanings
			S36	First Choice		Second Choice
			------------------------------------------------------------------
			0	Hang-up		N/A
			1	Async			Hang-up
			2	Hang-up		N/A
			3	Buffered Async	Hang-up
			4	MNP			Hang-up
			5	MNP			Async
			6	MNP			Hang-up
			7	MNP			Buffered Async


Cross Reference	S48 Feature Negotiation Action 
			S46 Protocol Selection



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S37 - Desired DCE Line Speed

-----------------------------------------------------------------------------------------------------------------------------
Description             During carrier handshake the modem attempts to
                        connect at the highest supported data rate that
                        does not exceed the value entered in this
                        register. This applies to originated and
                        answered calls; S37 sets the upper speed limit.

                        Lower speeds may be negotiated if the
                        appropriate Nn command is selected.

                        When doing a V.32, V.32 bis, or V.FC handshake,
                        the modem connects only at speeds enabled by
                        S109.

                        If Ans-A or Orig-A handshake behavior is
                        selected (defined for Nn command) and the speed
                        indicated by S37 is one of the set covered by
                        S109, then the speed must match one of the
                        speeds selected by S109 or when the modem enters
                        the handshake process the modem sets S86 to
                        value 16, hangs-up, and sends NO CARRIER result
                        code.

                        If the speed and modulation combination selected
                        by S37 and the corresponding Bn command is not
                        one of those affected by S109, then the
                        handshake proceeds normally. See the description
                        of S109 for the affected modulations.

                        If the DTE enters a reserved or undefined value
                        for S37, the modem returns ERROR and does not
                        change the value.

Type			value

Value range		see list below, Default value: 0 

Stored by &Wn	yes

Displayed by &V	yes

			Parameter 	Value Meanings
			------------------------------------------------
			0		Use Last AT Speed 
			1		Reserved (75) 
			2		Reserved (110)
			3		300
			4		Reserved (600) 
			5		1200 
			6		2400 
			7		4800 
			8		7200 
			9		9600 
			10		12000 
			11		14400 
			26		16800 
			12		19200 
			33		21600 
			29		24000 
			34		26400 
			15		28800


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S38 - Hang-up Timeout

-------------------------------------------------------------------------
Description             The following applies to calls during which data
                        may be buffered.

                        If the modem detects loss of carrier or a
                        clear-call message from the distant modem, or
                        the DTE requests that the call be cleared (by
                        ATH or DTR going off while &D2 is selected),
                        then the modem starts a timer at time specified
                        by S38 and does the following.

                        1.      If hanging up at user's request (ATH
                        command or DTR goes off), then the modem
                        discards the receive buffer and transmits
                        contents of transmit buffer. After this is done,
                        the modem conducts orderly shutdown of
                        error-control protocol (if any). If the contents
                        of the transmit buffer are sent before the S38
                        time limit, then the modem hangs up and returns
                        the OK result code. If the timer expires before
                        the contents are sent, then the modem hangs up
                        and returns the NO CARRIER result code. An S38
                        value of 0 forces the NO CARRIER result.

                        2.      If hanging up because of loss of
                        carrier, orderly shutdown initiated by other
                        side, or protocol failure, then the modem
                        discards the transmit buffer, goes on hook, and
                        sends the contents of receive buffer to the DTE
                        for the time set by the value of S38. When the
                        time limit is reached or the buffer contents are
                        sent to the DTE, the modem returns the NO
                        CARRIER result code.

                        If the modem is blocked from sending buffered
                        data to the DTE because of flow control, then
                        the modem continues to attempt to send the data
                        and terminates the attempt or the sending when
                        the timer expires.

                        This register does not affect AutoSync II
                        operation; buffered data is discarded.

Type			value (seconds) 

Value range 		0 to 255, Default value: 20 

Stored by &Wn	yes 

Displayed by &V	yes 

Parameter Values	0-254: Number of seconds to send buffered data before 
			clearing the call.

                        255: Modem sends all buffered data and then
                        clears the call (no time limit).

                        Note: If the connection is lost, the modem does
                        not attempt to send any more buffered data.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S43 - Current Line Speed

-----------------------------------------------------------------------------------------------------------------------------
Description             The value in this register indicates the line
                        speed of the last carrier established.

Type			value, read only 

Value range 		0, 2-12, 15, 26, 29, 33, 34; Default value: 0 

Stored by &Wn	no 

Displayed by &V	no 

Values meanings	
			Parameter 	Value Meanings
			--------------------------------------------
			0		No Connection 
			1		Reserved (75) 
			2		110
			3		300 
			4		600
			5		1200 
			6		2400 
			7		4800 
			8		7200 
			9		9600 
			10		12000 
			11		14400 
			26		16800 
			12		19200 
			33		21600 
			29		24000 
			34		26400 
			15		28800


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S44 - Framing Technique

-------------------------------------------------------------------------
Description		Permits you to specify error-control connection type.

Type			value 

Value range 		2, 3: Default value: 3 

Stored by &Wn	yes 

Displayed by &V	no 
Parameter Values        2: Negotiate asynchronous only, if MNP attempt.
                        This can be used to force an MNP-2 connection
                        for tests.

                        3: Negotiate either synchronous (preferred) or
                        asynchronous if MNP.



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S46 - Protocol/Compression Selection

-----------------------------------------------------------------------------------------------------------------------------
Description             When &Q5 is selected, S46 permits you to select
                        whether or not to negotiate compression, and to
                        select the priority for negotiating protocols,
                        if any.

                        When negotiating MNP, the class negotiated is
                        determined by bit 1. MNP Class 5 is negotiated
                        if bit 1 is set, and MNP Class 4 is negotiated
                        if it is cleared.

Type			bit mapped 

Value range 		0 to 31, Default value: 2 

Stored by &Wn	yes 

Displayed by &V	yes 

Bit Map	
			Bit 	Value Meanings
			--------------------------------------------
			0	Ignored
			1	Enable compression 
			2	Ignored
			3	Ignored
			4	Prevent LAPM protocol 
			5	Ignored
			6	Ignored
			7	Ignored

Cross Reference S48 Feature Negotiation Action, S36 Negotiation
Fallback, Chapter 8.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S48 - Feature Negotiation Action

-------------------------------------------------------------------------
Description             V.42 Feature Negotiation has two phases:
                        detection and negotiation using XID frames.

                        This register permits you to disable the V.42
                        detection phase.

Type			bit mapped 

Value range 		0 to 7, 128-135, Default value: 7 

Stored by &Wn	yes 

Displayed by &V	yes 

Bit Map	
			Bit 	Value Meanings
                        ------------------------------------------------
			0	Not used
			1	Not used (XID negotiation always enabled) 
			2	Enable XON/Escape Detection Phase
			3	Not used
			4	Not used
			5	Not used
			6	Not used
			7	Force fallback

Cross Reference	S46 Protocol Selection, S36 Negotiation Fallback


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S49 - Buffer Low Limit

-------------------------------------------------------------------------
Description             This S-register, in conjunction with S50 (Buffer
                        High Limit) determines the number of characters
                        which are buffered in Automatic Speed Buffering
                        (ASB) and error-control modes before the DTE is
                        flow controlled. When the number of characters
                        in the buffer reaches the value set by this
                        register, the DTE is flowed on.

                        If the value of S49 is larger than the value of
                        S50, then the values are interchanged during the
                        next handshake. If the value of S49 equals the
                        value of S50, then the value of S49 is reduced
                        by one during the next handshake.

                        Note: This feature is available in 28.8
                        kbits/second modems.

Type			value 

Value range 		1 to 249, Default value: 64 

Stored by &Wn	yes 

Displayed by &V	yes 

Cross Reference	&Q5 Error Control Mode, 
                        &Q6 Automatic Speed Buffering Mode, S36
                        Negotiation Fallback Options, S50 ASB: High
                        Limit


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S50 - Buffer High Limit

-------------------------------------------------------------------------
Description             This S-register, in conjunction with S49 (Buffer
                        Low Limit) determines the number of characters
                        which are buffered in Automatic Speed Buffering
                        (ASB)and error-control modes before the DTE is
                        flow controlled. When the number of characters
                        in the buffer reaches the value set by this
                        register, the DTE is flowed off.

                        If the value of S49 is larger than the value of
                        S50, then the values are interchanged during the
                        next handshake. If the value of S49 equals the
                        value of S50, then the value of S49 is reduced
                        by one during the next handshake.

                        Note: This feature is available in 28.8
                        kbits/second modems.

Type			value 

Value range 		2 to 250, Default value: 192 

Stored by &Wn	yes 

Displayed by &V	yes 

Cross Reference	&Q5 Error Control Mode, 
                        &Q6 Automatic Speed Buffering Mode, S36
                        Negotiation Fallback Options, S49 ASB: Low Limit


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S70 - Maximum Number of Retransmissions

-----------------------------------------------------------------------------------------------------------------------------
Description             S70 sets the number of times the modem
                        retransmits a frame while using while using
                        error-control link layer protocol.
                        Retransmissions become necessary when data
                        errors introduced by noise disrupt the reception
                        of a frame. When the limit set by S70 is
                        reached, the modem hangs up. Raising this limit
                        may be necessary if, for example, telephone
                        lines are extremely noisy.

                        See also parameter N400 in CCITT Recommendation
                        V.42.

                        Note: This feature is available in
                        28.8kbits/second OPTIMA modems.

Type			value 

Value range 		1-255, Default value: 10 

Stored by &Wn	yes 

Displayed by &V	no 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S73 - No Activity Timeout

-----------------------------------------------------------------------------------------------------------------------------
Description             The modem sends an RR frame to the distant modem
                        after inactivity (no data sent or received) for
                        the time specified by S73. See also T402 in
                        CCITT recommendation V.42.

                        Note: This feature is available in 28.8
                        kbits/second OPTIMA modems.

Type			value (seconds) 

Value range 		1-255, Default value: 5 

Stored by &Wn	yes 

Displayed by &V	no 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S82 - Break Selection

-----------------------------------------------------------------------------------------------------------------------------
Description             This register determines how breaks are
                        transmitted during error-control and ASB calls.
                        The following options are provided.

                        In-sequence means a break is sent to the distant
                        end after any buffered data, without disrupting
                        the data being transmitted. Incoming data is
                        sent to the local DTE after any buffered data.

                        Expedited means breaks are sent to the distant
                        end or delivered to the DTE before any buffered
                        data, while maintaining the integrity of the
                        data.

                        Destructive means all buffered data is discarded
                        before the break is sent; the buffered data is
                        lost. Destructive implies expedited; the break
                        is sent instead of buffered data. Thus
                        destructive and expedited breaks occur if the
                        value of bit 2 is 1, independent of bit 1.

                        V.42 LAPM provides a means for the sending end
                        to tell the receiving end when a break is timed
                        or not. The receiving modem delivers breaks that
                        are timed according to the indication from the
                        distant modem.

                        When using LAPM, timed break duration's are in
                        increments of 10 ms. Timed breaks are sent with
                        duration equal to the closest time increment
                        that is not less than the duration received from
                        the DTE.

                        If a V.42 Alternative Procedure connection is
                        made then the modem only provides untimed
                        breaks; bit 0 is ignored. The procedure does not
                        include a means for timed breaks.

                        When using ASB, timed breaks are timed according
                        to the procedure described in V.14: breaks that
                        last M to 2*M + 3 bits are sent with duration
                        2*M + 3 bits. Longer breaks are sent with their
                        true duration. Less than M spacing bits from the
                        DTE are ignored, not treated as breaks. The
                        duration of untimed breaks is the larger of 180
                        ms or 2M + 3 bits (M is the length of a
                        character).

                        When using ASB, incoming breaks are delivered to
                        the DTE in sequence, after any other buffered
                        data.

                        Note: V.14 specifies how breaks are handled when
                        that recommendation is in use.

Type			bit mapped, Factory Default Value: 1

Stored by &Wn	yes 

Displayed by &V	no 

Bit Map
			Bit 	Value Meanings
			---------------------------------------------------
			7	0 = untimed, 
				1 = timed (for compatibility) 
			6	reserved
			5	reserved 
			4	reserved 
			3	reserved 
			2	0 = not destructive, 
				1 = destructive 
			1	0 = in sequence, 
				1 = expedited 
			0	0 = untimed, 
				1 = timed


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S86 - Connection Failure Cause Code

-----------------------------------------------------------------------------------------------------------------------------
Description             This read-only register indicates why a
                        connection failed or was otherwise concluded
                        (either the desired protocol was not negotiated,
                        carrier loss, normal hang-up, etc.). The modem
                        places a value in this register whenever a NO
                        CARRIER result code is returned. Although
                        several events may contribute to the connection
                        failure, S86 reports the first event which
                        caused the failure.

                        The value of S86 is set within 10 ms of the NO
                        CARRIER result code (the end of the trailing
                        Ctrl-J) and is unchanged until the next NO
                        CARRIER result code is sent to the DTE.

Type			value, read only 

Value range 		listed below, Default value: 0 

Stored by &Wn	no 

Displayed by &V	no 

Value Meanings	
			Value 	Meaning 
                        -------------------------------------------------
			1	Normal hang-up from FAX call
			2	Reserved 
			3	Reserved 
			4	Lost carrier
                        5       Feature negotiation failed to detect
                                presence of another error- control modem
                                at the remote end.
                        6       Other error-control modem did not
                                respond to feature negotiation message
                                sent by this modem.
                        7       Other modem is synchronous-only, this
                                mode is asynchronous only.
                        8       Modems could not find a framing
                                technique in common (async or sync).
			9	Modems could not find a common protocol.
                        10      Feature negotiation message sent by
                                remote modem is incorrect.
                        11      Synchronous information (data or flags)
                                not received from other modem. Modem
                                waits 30 seconds before hanging up.
			12	Normal disconnect initiated by remote modem.
                        13      Remote modem did not respond after many
                                transmissions of the same message. Modem
                                attempts connection 10 times before
                                giving up.
			14	Protocol violation occurred.
			15	Compression failure.
                        16      Speed indicated by S37 did not match any
                                of the speeds indicated by S109.
			17	Hang-up was due to S116 time out.
			18	Inactivity timer S30 caused hang-up.
			19	Long space disconnect hang-up.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S91 - Select Dial-up Line Transmit Level

-----------------------------------------------------------------------------------------------------------------------------
Description             This register selects the transmit carrier level
                        of the modem in dBm [into 600 ohms]. This
                        register is only functional in certain
                        International (non-US) products. The nominal
                        output level is between 0 and 1 dB less than the
                        indicated level and the actual level of any unit
                        does not exceed the indicated level by more than
                        1 dB.

			The value of this register is stored when written. 

			This register is locked (write commands do not change current value)
			while the modem is in the online states and normally locked in the 
			off-line command state. The register may be unlocked, changed, 
			and locked for the off-line command state by the following steps.

			Note: This feature is not available in all OPTIMA and ACCURA 
products.

			Step 1:	Turn off modem. (Remove cover first.)

                        Step 2: Operate the switch (inside modem cover)
                                intended to enable transmit level
                                adjustment. This is usually SW2 of a DIP
                                switch.

			Step 3:	Turn on modem.

                        Step 4: Write a new value to the register using
                                the syntax AT S91=nn<CR>.

			Step 5:	Turn off the modem.

			Step 6:	Move the switch to the disable position.

                        Step 7: Turn on the modem. The modem will now
                                operate with the new transmit level.

Type			value (- dBm) 

Value range 		0 through 15, Default value: 10 

Stored by &Wn	N/A

Displayed by &V	no 

			Note: The output level is not adjustable in the US.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S95 - Extended Result Code Bit Map

-------------------------------------------------------------------------
Description             The bits in this register may be set to force
                        some of the characteristics of the Wn command
                        ON. If any of the bits below are set to 1, then
                        the corresponding result code is enabled
                        regardless of the Wn or Xn (n > 1) command in
                        effect. Refer to the Wn and Xn commands for
                        additional information. This register does not
                        affect the result codes selected by the X0
                        command.
			
Type			bit mapped, Default value 	0

Stored by &Wn	yes 

Displayed by &V	no 

Bit Function 	
			Value 	Bit	Function 
                        -------------------------------------------------
                        1       0       CONNECT result code (verbose or
                                        numeric) indicates the line
                                        speed (rather than the DTE
                                        speed).
                        2       1       Append "/ARQ" to the verbose
                                        CONNECT result code if the
                                        protocol is not "NONE". Example:
                                        "CONNECT 9600/ARQ".
			4	2 	Enable the CARRIER result codes.
			8	3	Enable the PROTOCOL result codes.
			16	4 	reserved 
			32	5 	Enable the COMPRESSION result codes. 
			64	6 	reserved 
			128	7 	reserved


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S97 - V.32 Late Connecting Handshake Timing

-------------------------------------------------------------------------
Description             During a V.32 automode handshake, the answer
                        modem sends unscrambled binary ones (USB1) for
                        the time called Ta. The value of S97 sets the
                        duration of Ta. During the handshake, the
                        originate modem waits a time, Tc, to check for
                        USB1. Tc is Ta plus 0.1 s.
			
                        S97 only affects Ta and, indirectly, Tc. If an
                        answer mode modem is set to answer at 2400
                        bit/second, S97 has no impact on how long USB1
                        is transmitted. If the automode handshake
                        sequence repeats itself, as when V.21 and V.23
                        are included, then S97 affects all cycles. The
                        Factory Default favors the existing installed
                        base of modems.
			
                        S97 may have a value from 15 to 70. Each unit of
                        S97 corresponds to 0.1 s in Ta.
			
                        Set S97 to 15 (1.5 sec) when compatibility with
                        V.32 late connecting modems is a primary
                        requirement.

Type			value (15-70), Default value 	30 

Stored by &Wn	yes 

Displayed by &V	no 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S105 - Frame Size

-------------------------------------------------------------------------
Description             This value indicates the maximum link layer
                        frame information field size that is attempted
                        with the V.42 protocol. The value equals the log
                        (to the base 2) of the field size in octets. The
                        frame size is the smaller of the size indicated
                        by the value of S105 and any restrictions
                        imposed by the particular link layer protocol in
                        use.

Type			(log[size]/log[2]) 

Value range 		4 to 9, Default value: 8 

Stored by &Wn	yes 

Displayed by &V	no 

Values
			Value 	Bytes 
			-------------------
			4	16 
			5	32
			6 	64
			7	128
			8	256
			9	512


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S108 - Signal Quality Selector

-------------------------------------------------------------------------
Description             This register only affects V.32 bis and V.FC
                        connections.

                        Register S108 sets the signal quality required
                        for the modem to handshake at the highest
                        designated speed and for automatic rate
                        re-negotiation.

                        If the modem determines during carrier handshake
                        that the signal quality is less than that
                        specified by S108, the modem attempts to connect
                        at the next lower speed indicated by S109,
                        unless the N0 command is selected. If the N0
                        command is selected, only the speed indicated by
                        S37 may be used (during handshake).

                        The signal quality (such as MSE) that
                        corresponds to each S108 value depends on line
                        speed. That is, larger MSE values should be used
                        at lower line speeds. The appropriate measure of
                        signal quality may be a function of modulation
                        and coding used.

                        The bit error rate (BER) values that correspond
                        to S108 values are listed below. These BER
                        values are determined for the modem with an
                        average channel and Gaussian noise.

Type			value 

Value range 		0-3, Default value: 1

Stored by &Wn	yes 

Displayed by &V	yes

Values
			Value 	Bytes 
			-------------------------------------------------
			0	no limit (10-2 BER) 
			1	low quality (i0-4 BER) 
			2 	medium quality (10-5 BER) 
			3	high quality (10-6 BER)


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S109 - Carrier Speed Selector

-----------------------------------------------------------------------------------------------------------------------------
Description             Register S109 selects the speeds available for
                        V.32, V.32 bis and V.FC carrier handshake,
                        retrains, and rate re-negotiations.

                        Register S37 selects the highest carrier speed
                        that may be used during handshakes. If the N0
                        command is selected, the speed indicated by S37
                        and one of the speeds selected by S109 must
                        match; the modem connects only at that speed.

                        Register S37 and the N0 command do not affect
                        the modem speed while in V.32 bis mode during a
                        retrain or rate re-negotiation procedure.

                        Note: When doing a V.32, V.32 bis, or V.FC
                        handshake, the modem connects only at speeds
                        enabled by S109.

                        If Ans-A or Orig-A handshake behavior is
                        selected (defined for Nn command) and the speed
                        indicated by S37 is one of the set covered by
                        S109, then the speed must match one of the
                        speeds selected by S109 or when the modem enters
                        the handshake process the modem sets S86 to
                        value 16, hang-up, and sends NO CARRIER result
                        code. If the speed selected by S37 is not one of
                        those covered by S109, then the handshake
                        proceeds normally.

Type			bit mapped, Default value 	4094

Stored by &Wn	yes 

Displayed by &V	yes

Bit Map
			Bit 	Value 
			----------------------------------
			0	Reserved 
			1	4800 bits/second 
			2 	7200 
			3	9600
			4	12000 
			5	14400 
			6	16800 
			7	19200 
			8	21600 
			9	24000 
			10	26400 
			11	28800 
			12	reserved 
			13	reserved 
			14	reserved 
			15	reserved 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S110 - V.32/V.32 bis Selector

-------------------------------------------------------------------------
Description             The V.32 and V.32 bis carrier handshake
                        procedures are compatible. The rate sequence
                        contains bit combinations that specify which
                        procedure is used. Register S110 provides
                        control of that selection for those who want to
                        limit carrier handshake procedure to that
                        specified by V.32 or to disable automatic rate
                        re-negotiation (rate changes initiated by the
                        modem based on signal quality).

                        When the value of S110 is 0, the V.32 handshake
                        procedure is followed, rate re-negotiation
                        (which is allowed by V.32 bis) is disabled, and
                        the &U command determines whether or not trellis
                        coding is enabled.

                        When the value of S110 is 1, the V.32 bis
                        handshake is enabled, but not automatic
                        re-negotiation. The modem responds to a rate
                        re-negotiate request from the other end, but
                        tells the other end that only the current speed
                        is available.

                        When the value of S110 is 2, V.32 bis both
                        handshake and - automatic rate re-negotiation
                        are enabled.

Type			value 

Range			0-2, Default value: 2 

Stored by &Wn	yes 

Displayed by &V	yes 

Values
			Bit 	Value 
                        -------------------------------------------------
			0	V.32 enabled 
			1	V.32 bis enabled
                        2       V.32 bis and automatic rate re-negotiation
                                enabled

Note: V.32 bis enabled includes V.FC if supported by the modem.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S113 - Calling Tone Control

-------------------------------------------------------------------------
Description             The value in this register determines whether
                        calling tone is transmitted during call
                        origination. If calling tone is sent, it starts
                        after dialing has been completed and continues
                        until answer tone or carrier is detected from
                        the answering modem. Calling tones comply with
                        the requirements of V.25.

                        Use of calling tone is regulated in certain
                        countries. In countries where calling tone is
                        required, S113 is not implemented in the modem.
                        That is, if calling tone is turned on, then S113
                        always has value 1 and if the command S113=0 is
                        sent, then the modem returns OK but does not
                        change the value.

Type			value 

Value range 		0-1, Default value: 0 

Stored by &Wn	yes 

Displayed by &V	no 

Parameter Values	0 calling tone is not sent 
			1 calling tone is sent



+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S121 - Use of DTR

-------------------------------------------------------------------------
Description             Register S121 selects how the time indicated by
                        the value of S25 affects the recognition of
                        changes in the state of DTR. The behavior
                        defined for value 1 allows the modem to be used
                        with a system that does not provide a DTR
                        signal.

                        Note: This feature is not supported in all
                        OPTIMA and ACCURA products.

Type			value 

Value range 		0-1, Default value: 0 

Stored by &Wn	yes 

Displayed by &V	no 

Values                  0 - Normal DTR state and state change behavior
                        as defined by &Dn commands.

                        1 - If DTR is off, it is ignored (does not need
                        to be on to maintain a connection). If DTR goes
                        from off to on, it is ignored. If DTR goes from
                        on to off, obey &Dn command. This value is not
                        intended inhibit autoanswer.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S141 - Detection Phase Timer

-------------------------------------------------------------------------
Description             This register sets the V.42 detection phase
                        timeout, T400, which determines how long a modem
                        waits for an Originator Detection Pattern (ODP)
                        or Answerer Detection Pattern (ADP) before
                        abandoning its attempt to establish an
                        error-correcting connection. The action to take
                        if the error-correcting attempt is abandoned is
                        determined by the value of S36.
			
                        An originating modem waits for the time
                        indicated by the value of S141 to detect an ADP
                        pattern. An answering modem waits for the
                        indicated time to detect the ODP pattern. If the
                        answering modem receives ODP, then the answer
                        modem sends the ADP pattern and waits for flags
                        for up to twice the T400 time. If flags are not
                        detected, then the modem hangs-up.

Type			value (centiseconds) 

Value range 		10-255, Default value: 85 (850 ms) 

Stored by &Wn	yes 

Displayed by &V	no 


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S142 - Online Character Format

-----------------------------------------------------------------------------------------------------------------------------
Description             S142 determines the DTE-DCE character format the
                        modem uses while in the online state and using
                        V.14, V.42, V.42bis, or ASB interface
                        procedures. S142 does not affect the DTE-DCE
                        character format when the modulation type is FSK
                        and ASB is not in use.

Type			value 

Value range 		0-5, Default value: 0 

Stored by &Wn	yes 

Displayed by &V	yes 

Values
			Bit 	Online state character format
                        -------------------------------------------------
			0	8N1 (this also covers all 7x1 formats) 
			1	8E1 
			2	8O1 
			3	8M1 (same as 8N2) 
			4	8S1 
			5	Format of last command.


                        The effect of S142 depends on the DTE Interface
                        protocol used, as described below.

                        V.14 - The modem sends and receives characters
                        in the selected format. This preserves parity
                        bits during transmission.

                        V.42 and V.42bis - The modem sends and receives
                        octets as prescribed by V.42, and absorbs and
                        generates parity bits of 11-bit characters
                        locally. While this procedure does not transmit
                        parity bits between DCEs, it does conform to
                        V.42.
			
                        ASB - The modem buffers octets but sends
                        selected parity to other DCE, using V.14
                        procedure. The modem receives the selected
                        parity from other DCE and passes it on to local
                        DTE. This procedure passes parity bits between
                        the DCEs and allows detection of line errors as
                        parity errors.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S144 - Autobaud Speed Group Selection

-----------------------------------------------------------------------------------------------------------------------------
Description             Depending on your computer model and the year it
                        was made, your modem supports a set of DTE
                        speeds. For the highest possible DTE speed
                        obtained through speed negotiation, select the
                        value of S144 that best describes your computer.
                        The default is for this S- register. is 0.

Type			value 

Value range 		0-2, Default value: 0 

Stored by &Wn	yes 

Displayed by &V	no 

Value Speeds            0 - Standard DTE Speed, Use S144 =0, if your
                        computer is not an NEC PC-9800 series. S144=0
                        supports the following DTE speeds: 300, 600,
                        1200, 2400, 4800, 7200, 9600, 12000, 14400,
                        19200, 38400, and 57600 bits/second.

                        Set 1 - DTE Speeds for NEC PC-9800 Series
                        Computers, Use S144 =1, if your computer is an
                        NEC PC-9800 series model which supports the
                        following DTE speeds: 300, 600, 1200, 2400,
                        4800, 9600, 20800, 31200, 41600 and 62400
                        bits/second.

                        Set 2 - DTE Speeds for NEC PC-9800 Series
                        Computers, Use S144 =2, if your computer is an
                        NEC PC-9800 series model which supports the
                        following DTE speeds: 300, 600, 1200, 2400,
                        4800, 9600, 19200, 38400, and 51200 bits/second.

                        As a general guideline, the DTE speeds
                        designated as Set 1 are supported by NEC PC-9800
                        series models, manufactured prior to 1993. The
                        DTE speeds designated as Set 2 are supported by
                        NEC-9800 series models, manufactured during or
                        after 1993. Refer to your computer's user
                        documentation to determine which set your
                        computer supports.

                        Note: The speeds available with value 0 may be
                        limited by selections made in the feature table.

                        Note: The commands %Nx (x = 0,1,2) also set S144
                        to value x.


=========================================================================
Chapter 7
Modem States


*************************************************************************
Modem Functions

Hayes modems provide auto dial and auto answer functions in addition to
transmission and reception of data signals. The modem goes off hook,
dials numbers, connects to a distant modem (handshakes), modulates data
from a local DTE for transmission, and demodulates received signals from
a distant modem. The modem also provides many auxiliary functions,
including several types of tests. The AT command set facilitates control
and observation of modem functions.


*************************************************************************
Major States

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Idle State

In the Idle State, the modem is not communicating with a distant end,
and, if not in dumb mode, is ready to accept commands. The modem is
usually on hook while in the Idle State, but may be off hook. The modem
goes into the Idle State directly after it's powered-on. See Chapter 13.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Dialing State

In the Dialing State the modem may be waiting for dial tone, sending
dialing signals, pausing, or some other dialing operation. The modem
enters the dialing state as a result of executing the D command. Refer
to the Dialing Process in Chapter 8 for more information.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Handshaking State

In the Handshaking State the modem may be sending answer tone, waiting
for answer tone, or handshaking with another modem. The modem enters
Handshaking State when one of the following occurs:

*	Dialing Process
*	Modem autoanswer
*	DTR OFF-to-ON transition when &Q3 is in effect
*	Power is turned on in the dumb leased-line mode. 

The handshaking process can be running in the originate mode or the
answer mode. Refer to the &Dn command in Chapter 4 and the "Handshaking
Process" in Chapter 8 for more information.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Online State

In the Online State the modem sends and receives data with a distant
modem. The modem may enter the Online State from the Handshaking State
as a result of the Handshaking Process or from the Online Command State
as a result of the On command. Signals from the DTE are treated as data
and transmitted to the distant end. Refer to the O command in Chapter 4
and Online State in Chapter 8 for more information.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Online Command State

In the Online Command State the modem will maintain the connection with
the distant modem, but it treats DTE signals as commands. The modem may
enter the Online Command State as a result of the Hayes Patented Escape
Process with guard time or as a result of a DTR ON-to-OFF transition
when certain combinations of &Dn and &Qn are in effect. The Online
Command State only exists in the Smart Mode. Refer to the &Dn and &Qn
commands in Chapter 4, and the "Hayes Patented Escape Process with guard
time " and "Online Command State" in Chapter 8.


=========================================================================
Chapter 8
Processes and Procedures


This Chapter describes basic modem processes and procedures.


**************************************************************************************************
Answering Process

The answering process is used to answer a call. The process may be
started by the A command, by turning DTR on, by the modem detecting a
certain number of ring events, or by power going on in the dumb
leased-line mode.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Entry

Enter Answer Mode from Idle State if:

*       The A command is sent to the modem while &Q0, &Q1, or &Q4 is in
        effect.

*       A ring signal is detected, &Q0, &Q1, or &Q4 is in effect, S0>0,
        and S1>=S0. If &D2 is in effect, then DTR must also be ON. If
        DTR goes ON after the ring for which S1>=S0, then the answer
        process begins after the end of the next ring following the RING
        result code.

*       A ring signal is detected, &Q2 or &Q3 is in effect, S0>0,
        S1>=S0, and DTR goes on after the first ring. The answer process
        begins after the end of the ring for which S1>=S0 following the
        RING result code. If DTR goes ON after the ring for which
        S1>=S0, then the answer process begins after the end of the next
        ring following the RING result code.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Exit

Exit the answering process as follows:

*	Exit to Handshaking state if Answering process is completed.

*	Exit to Hard Reset if &D3 and DTR go on-to-off.

*	Exit to hang-up process if:

*	Key press abort (if enabled by &Q command). Result code: NO CARRIER

* 	&D2 and DTR goes on-to-off. Result code: OK

*	(&Q1 or &Q4) and &D0 and DTR go on-to-off. Result code: OK

*	(&Q2 or &Q3) and DTR go on-to-off Result code: OK

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Execution Time

The steps listed below take a maximum of 10 ms to execute. (More time
may be taken by the handshaking process.)

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process Steps

*	Set speaker volume according to Ln and Mn commands.

*	If &Q2 or &Q3 is in effect, turn off CTS.

*	If &Q1 or &Q4 is in effect, and S0>0, turn off CTS.

*	Go off hook.

*	Turn on OH LED.

*	Go to handshaking process, answer mode.


**************************************************************************************************
Carrier Detection

Carrier detection while the modem is in the online state is governed by
the times specified by registers S9 and S10. The CD LED is the carrier
detected indicator. If the carrier signal goes off, the CD LED goes off
within 20 ms. If the carrier returns, the CD LED turns on within 20 ms
after the carrier has been on continuously for the time specified by S9.

If the carrier remains off for the time specified by S10, then the modem
hangs up. If S10 is set to 255, the time is considered to be infinite;
the modem does not hang up due to loss of carrier signal.

Various algorithms may be used by a modem to detect carrier, in addition
to estimating received signal power. When any of these algorithms
indicate carrier is not being received, the S9 and S10 time intervals
are used to determine when to clear the call.

See also the &Cn command in Chapter 4 for RLSD behavior.


**************************************************************************************************
Dialing Process

The dialing process causes the modem to go off hook, wait for dial tone,
and send the dial digits or execute the dial modifiers in the dial
string. The process may be started by a command from the DTE, or by DTR
going on while the &Q2 command is in effect.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Execution Time

The dialing process requires the time to send the dialing signals and
execute any dial modifiers. See the individual commands and dial
modifiers for execution times.

The modem enters the dialing process if:

*	D command is entered (if the command is valid)

*       &Q2 and DTR comes on and ringing has not been detected (i.e.,
        S1=0) In this case, stored number 0 is dialed.

The modem exits the dialing process as follows:

*	Hard Reset if &D3 and DTR go on-to-off.

*	Handshaking State if dialing process is completed.

*	Idle State if a semicolon dial modifier is executed.

*	Hang-up Process if:

*	Key press abort (not &Q2 or &Q3). Result code: NO CARRIER

*	(not &Q2 or &Q3) and &D2 and DTR go on-to-off Result code: OK

*	(&Q1 or &Q4) and &D0 and DTR go on-to-off Result code: OK

*       (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR go on-to-off Result
        code: OK

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process Steps

Step 1:		If the modem is off hook, go to Step 11.

Step 2:		Set speaker volume according to Ln and Mn commands.

Step 3:		If &Q2 or &Q3 is in effect, turn off CTS.

Step 4:		If &Q1 or &Q4 is in effect, and S0>0, turn off CTS.

Step 5:		Go off hook and turn on OH LED.

Step 6	:	If &J1 is in effect, operate auxiliary relay.

Step 7:		If &L1 is in effect, go to handshaking process, originate mode. 

Note: Dial digits and dial modifiers are ignored in leased-line mode
                (&L1 in effect).

Step 8:         If &Q3 is in effect, go to handshaking process,
                originate mode.

Step 9:         If (X2 or X4) is in effect, then look for 1 second of
                dial tone within 5 seconds. If no dial tone in 5
                seconds, go to hang-up process with NO DIALTONE result
                code. If dial tone is detected, proceed.

Step 10 If X0, X1, or X3 is in effect, then wait for time indicated by
                S6, then proceed. This is blind dialing.

Step 11:        Do the following four steps until all of the dial digits
                and dial modifiers have been executed, then go to Step
                12.

		(a)	Examine next dial digit or dial modifier.

                (b)     If a dial modifier, then execute. If the dial
                        modifier is the semicolon then go to the idle
                        state and continue execution of the command
                        line.

                (c)     If a dial digit and tone dialing, send DTMF tone
                        with duration indicated by S11 and wait for time
                        indicated by S11 before going on to next dial
                        digit or modifier.

                (d)     If a dial digit and pulse dialing, send the
                        indicated number of pulses. Each pulse consists
                        of opening the line relay (break) and closing
                        the line relay (make) for the times determined
                        by which &Pn command is in effect. Wait for
                        interdigit delay time before going on to the
                        next dial digit or dial modifier.

                Note: Dial digits A, B, C and D cannot be sent by
                      dial pulses and are ignored.

Step 12:        If one of the dial modifiers was R, go to handshaking
                process, answer mode. Otherwise go to handshaking
                process, originate mode.


**************************************************************************************************
Hayes Improved Escape Sequence with Guard Time

The Hayes Improved Escape Sequence with Guard Time (U.S. Patent
#4,549,302) is used when the modem is on-line and you need to enter
commands to the modem without disconnecting. The escape sequence with
guard time protects you against losing the connection while you are
sending commands to your modem.

A guard time must precede and follow the sequence of escape characters
so that, should the same characters need to be transmitted in a message,
the modem will not accidentally switch to command state. The default
guard time is 1 second.

The escape sequence character and the guard time interval can be changed
by assigning different values to registers S2 (for the escape character)
and S12 (for the guard time).

To use the escape sequence with guard time:


Step 1:		Pause a little longer than the guard time.

Step 2:		Type +++.

Step 3:         Pause again a little longer than the guard time. (These
                pauses help the modem to distinguish the escape sequence
                from your message.)

Step 4:		Enter any necessary commands to the modem.

Step 5:         When you are ready to resume your call to a remote
                system, type ATO <CR>. The modem will return to the
                on-line state.


**************************************************************************************************
Handshaking Process

When the modem is sending answer tone, receiving answer tone, or
handshaking with another modem, it is said to be in the handshaking
state. The handshaking process can be run in either the originate or
answer mode and is designed to follow both domestic (Industry Standard
103, 212A), international (e.g., ITU-T [formerly CCITT]
recommendations), and proprietary procedures. In the originate mode, if
X3 or X4 command is in effect, the modem will monitor for a busy signal
after dialing.

The handshaking process is timed twice by the time specified by register
S7. If answer tone is not detected within the specified time after the
handshake process starts, the process will exit to the hang up process.
The timer is reset when answer tone is detected. If the modem does not
finish handshaking with the distant end within the specified time, the
modem exits to the hang up process.

The line speed at which the modem will attempt to connect is determined
by the Nn and Bn commands, the last AT speed, the value of S37, the
selected &Q command, S108, S109, S110. If all of these have their
default values, then the modems will attempt a line speed that is
determined by their AT speeds according to the table below. If S37 is
not zero, then S37 selects the maximum line speed. (Refer to the S37
definition for more details.)

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Execution Time

The process either completes within twice the time specified by S7 or it
aborts. Timing of answer tone transmission is determined by the
applicable modem technical requirements. The process may abort; the time
limits are discussed below.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Entry

The modem enters the handshaking process if:

*       From dialing or answering processes. If &S1 is in effect,
        turns DSR on.

*	From Idle State by On command if off-hook.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Exit

The modem exits from handshaking process to:

*	Hard Reset if &D3 is in effect and DTR goes on-to-off.

*       Online state if Handshaking is successful. Result code CONNECT.
        If &C1 is in effect, RLSD goes on after connect result code.

*	Hang up process if:

*       Answer tone is not detected within the time specified by S7; NO
        CARRIER result code.

*       If X3 or X4 is in effect and busy signal is detected before
        answer tone; BUSY result code.

*       Modem handshake is not completed in time specified by S7. Result
        code NO CARRIER.

Note:   Modem handshake time out begins after answer tone or carrier is
        detected and is a separate use of S7.

*	&Q2 or &Q3 and DTR goes on-to-off. Result code OK

*	(not &Q2 or &Q3) and key press abort. Result code: NO CARRIER

*	(not &Q2 or &Q3) and &D2 and DTR goes on-to-off Result code: OK

*	(&Q1 or &Q4) and &D0 and DTR goes on-to-off Result code: OK

*       (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR goes on-to-off
        Result code: OK

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process Steps

Step 1:         Start a timer at time specified by S7. If in originate
                mode, then go to Step 2. If in answer mode, go to Step 5.

Step 2:         If X3 or X4 is in effect and busy tone is detected, then
                exit to hang up process with BUSY result code. If answer
                tone or carrier is detected, then go to Step 3. If
                neither tone is detected before the timer times out,
                then exit to hang-up process with NO CARRIER result
                code.

Step 3:         Start a timer at time specified by S7. If carrier is
                detected, then turn on CD LED and go to Step 4. If
                carrier is not detected before the timer times out, then
                exit to hang-up process with NO CARRIER result code.

Step 4:         If &S1 is in effect, then turn on DSR. Continue with
                modem handshake. If modem handshake completes before the
                timer times out, then go to Step 7. Otherwise go to
                hang-up process with NO CARRIER result code.

Step 5:         Wait 2 seconds. If &S1 is in effect, then turn on DSR.
                Send answer tone. Start a timer at time specified by S7
                and go to Step 6.

Step 6:         Turn on CD light and complete modem handshake after
                carrier is detected. Send CARRIER and PROTOCOL result
                codes (if enabled) after the carrier and protocol
                negotiations complete, go to Step 7. If timer times out
                before modem handshake is completed, then exit to
                hang-up process with NO CARRIER result code.

Step 7:         Send CONNECT result code and set response speed to equal
                the line speed. If &C1 is in effect, turn on RLSD. Go to
                online state.

Notes:

a)      See the "Carrier Detection Process" and CD light behavior for
        details of CD LED operation.

b) 	See RLSD lead behavior for details of its operation.

c)      Result codes passed to the hang-up process are sent to the DTE
        at the end of the process.

d)      The handshake process is restarted if the &L1 command is in
        effect and S7 times out.

e) 	The following events aborts all handshake process steps:

        i)      (&Q0, &Q1, or &Q4) and key press abort. Result code is
                NO CARRIER.

        ii)     (&Q0 or &Q1 or &Q4) and &D2 and DTR goes on-to-off.
                Result code is OK.

        iii)    (&Q1 or &Q4) and &D0 and DTR goes on-to-off. Result code
                is OK.

        iv)     (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR goes
                on-to-off. Result code is OK.

        v)      Exit to Hard Reset if &D3 is in effect and DTR goes
                on-to-off. No result code.


************************************************************************
Hang-up Process

The hang-up process readies the modem for the idle state. Result codes
passed to the process are sent to the DTE at the end of the process.
This process completes in 1.5 to 2 sec plus any processing time, which
is implementation dependent.


************************************************************************
Resets

There are several levels of reset, depending on what triggered the
action. You can view the resets as the following sequence: (1) self
test, (2) EEPROM tests, (3) read switch settings, (4) establish profile
and other actions.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Power On Reset

When the modem power is turned on, the reset process starts at Step 1,
below. A hard reset, caused by DTR going off while &D3 is selected,
starts the reset process at Step 2, below. The Z command starts the
process at Step 3, below.

At the end of a power on reset, the modem will have loaded the profile
specified by the &Yn command.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Hard Reset

A hard reset is initiated by DTR going on-to-off while &D3 is in effect.
When a hard reset occurs, the modem performs the following actions:

Step 1:		Hangs up.

Step 2:		Turns on the HS and MR LEDs.

Step 3:         Copies into the active profile area the stored profile
                that is specified by the &Yn command.

Step 3:         The hard reset process ends with the modem going to the
                idle state, on hook. No result code is sent to the DTE.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Execution Time

A hard reset shall be completed in 2 seconds or less as may be required
by the product implementation.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Soft Reset

The reset initiated by the Z command may be called a soft reset. See the 
command description of the actions started by the command.


*************************************************************************
Key Press Abort

Key Press Abort refers to the aborting of an answering, dialing, or
handshake process as a result of the DTE sending any character to the
EIA-232D interface of the modem. The modem recognizes and responds to
any such received character within 500 ms and goes to the hang-up
process. The result code depends on the process being aborted. Refer the
"Dialing", "Answering", and "Handshaking Processes" sections in this
Chapter.


*************************************************************************
Online State

The online state is the modem state wherein a modem is able to send and 
receive modulated data signals to and from a remote modem.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Entry

Enter the Online State from O0 or O1 commands or from handshaking states.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Exit

The modem exits to online command state if:

Note: OPTIMA products support &Q1, &Q2 and &Q3.

*       Not (&Q1 or &Q2 or &Q3 or &Q4) and the Hayes Patented Escape
        Sequence with guard time completes. Result code is OK.

*       (&Q0 or &Q1 or &Q4) and &D1 and DTR goes on-to-off. Result code
        is OK.

The modem exits to hang-up process state if:

*       (not &Q2 or &Q3) and &D2 and DTR goes on-to-off. Result code is
        OK.

*	(&Q1 or &Q4) and &D0 and DTR goes on-to-off. Result code is OK.

*       (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR on-to-off. Result
        code is OK.

*       Carrier signal is lost. See "Carrier Detection". Result code is
        NO CARRIER.


***********************************************************************
Online Command State

The Online Command State is used to give the modem commands while
holding a connection to the distant end. While in this state, data
cannot be sent or received. The distant end receives continuous mark
signal. Characters from the DTE are treated as commands.

Received data patterns, RDL requests, and equalizer retrain requests
from the distant end are honored while the modem is in the Online
Command State.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Entry

*       Enter Online Command State from the online state if in Smart
        Mode, (not &Q2 or &Q3) is in effect, DTR goes ON-to-OFF, and DTR
        remains OFF for more than the time indicated by register S25.

*       Enter Online Command State from the online state if in Smart
        Mode, (not &Q2, &Q3, or &Q4) is in effect, and the Hayes
        Patented Escape Sequence with guard time is performed from the
        DTE at the Line Speed. Refer to "Hayes Patented Escape Sequence
        with guard time" in this Chapter.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Exit

*	Exit to Hard Reset if &D3 and DTR goes on-to-off.

*	Exit to online state if:

*	O command is entered. Result code is CONNECT.

*       O1 command is entered and retrain is successful. Result code is
        CONNECT.

*	Exit to idle state if:

*       O1 command is entered and retrain is not successful. Result code
        is NO CARRIER.

*       Exit to idle state if carrier is lost for the time specified by
        S10. Result code is NO CARRIER.

*	Exit to hang-up process if:

*       (not &Q2 or &Q3) and &D2 and DTR goes on-to-off. Result code is
        OK.

*	(&Q1 or &Q4) and &D0 and DTR goes on-to-off. Result code is OK.

*       (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR goes on-to-off.
        Result code is OK.


************************************************************************
Response To Ringing

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
General

The RI lead follows the presence of a ringing input. The S1 register
value is incremented after the end of each ring detected. Unless result
codes are inhibited by the Qn command or the modem is in the command
editing or execution state, the RING result code is sent to the DTE
after the end of each burst of power that is deemed to be a valid ring
signal. Valid ring signal depends on country.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
RI Lead

The RI lead is turned on immediately after ringing is detected and
remains on until 600 ms of no ringing is detected. This means that short
off intervals between ring-events are ignored. It also means that the
ringing indications are stretched by 600 ms.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S1 Register.

The S1 register is incremented immediately after the RI lead is turned
off. S1 is reset after 8 seconds if S1 has not been incremented
meanwhile.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
RING Result Code.

The RING result code shall be issued after S1 is incremented.


************************************************************************
RDL Process

If the modem is in the online state with &T4 in effect, then when it
detects an RDL request from the distant end it sends the acknowledgment
signal (defined in V.22 and V.22 bis) to the distant end and starts
repeating all received data back to the distant end. The RDL process is
said to be operating while the modem is repeating received data back to
the distant end. Received data is not sent to the DTE and the MR light
is flashed while the RDL process is operating.

When the RDL termination signal is received from the distant end, the
modem acknowledges the signal and returns to normal online operation.

Because the RDL requester is in the Online Command State, that modem may
also accept any commands that are otherwise valid in that context,
including the &T0 command that terminates the RDL process.

Because the grantor is in the online state, that modem also responds to
the Hayes Patented Escape Sequence with guard time, thereby allowing
that modem to issue the &T0 or other command.

Timing of remote digital request and acknowledgment signals is specified
in ITU-T V.22.


=========================================================================
Chapter 9
FAX Functions


*************************************************************************
Introduction

Group 3 facsimile (FAX) service, based on ITU-T recommendations T.4 and
T.30 [2,4], is widespread.

Note: References are listed at the end of this chapter.

Hayes modems may include Group 3 FAX capability. Control of FAX modems
is by means of the DTE to DCE interface specifications for modems, known
as Class 1[1]. Class 1 provides a set of primitive commands and result
codes [1]. The DTE must provide T.30 session management and T.4 image
handling.

This Chapter contains specifications for the features and performance of
Hayes facsimile modems based on Class 1 interface commands and
responses. New commands, S-registers, and result codes for FAX are
included.

This Chapter describes how the functions work; not which functions are
included in particular products. Individual product requirements need to
indicate which functions are required for products.


*************************************************************************
Philosophy

The modem provides a separation of data and FAX commands. In particular,
data commands that affect the definition of certain characters (S3, S4,
etc.), determine how many rings to detect before automatic answering
(S0), and set the response behavior (E, Q, and V) which affect both FAX
and data behavior. All other commands that determine the modem behavior
while on line apply only to data calls. The FAX command +FCLASS
determines whether the modem is currently in the data or FAX mode.

The behavior of DTE Interface control leads and lamps while the modem is
in a FAX mode is the same as when in the data mode. That is, there is no
special behavior for the FAX modes.


Data and FAX parameters are stored, loaded, and reset as follows:

*       The &F command restores Factory Default values of all data and
        FAX parameters.

*       The Zn commands clear any call, load the appropriate set of data
        parameters, and set +FCLASS = 0. The Zn commands do not change
        any other FAX parameters.

*       The &Wn commands store data parameters. FAX parameters are not
        stored; most FAX programs send FAX parameters to a modem before
        using the modem for a call.

The modem is in data mode when +FCLASS equals 0, the default value for
this parameter. When the value of +FCLASS is 1 the modem is in a FAX
mode.


*************************************************************************
Modem FAX Modes

As mentioned above, a modem may be used in one of three modes:

*	smart AT
*	switched smart
*	switched Dumb.

Note: OPTIMA products support the switched Dumb Mode feature.

The FAX mode is a subset of the smart AT, switched mode of operation.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
FAX Class 1 Mode

When the value of the parameter +FCLASS is 1, the modem is in the FAX
Class 1 mode. In this mode all data commands, plus the commands,
behavior, and responses defined in [1] are valid.


*************************************************************************
DTE Interface Leads

The following circuits are required.

*	Signal ground 
*	Transmitted data 
*	Received data.

The following circuits are optional.

*	Request to send (for flow control) 
*	Clear to send 
*	Data terminal ready 
*	Received line signal detector 
*	Ring indication.

Hayes modems provide the usual 
DTE Interface leads, which include the 
required and optional leads listed above.


*************************************************************************
General FAX Operation

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
FAX Commands and Responses

All FAX messages have the prefix +F. The three types of messages are
action commands, responses, and parameters. Commands are sent from the
DTE to the DCE. Responses are messages from the DCE to the DTE.
Parameter values may be passed in either direction. The DTE may set
values; the DCE may report Values.

Parameters are assigned values by commands of the form +FPARM=value,
where PARM means any parameter name. Current parameter values can be
read by the DTE using commands of the form +FPARM?. The DCE responds
with a string of values or lines of information text.

The +FCLASS parameter sets the basic mode of the modem as mentioned
above. The parameter values are:

+FCLASS 	Meaning
----------------------------------
0	data mode
1	FAX Class 1

The +F parameters may be changed while the modem is in data mode and off
line.

Invalid FAX commands and FAX commands that cannot be executed cause an
ERROR result code.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
FAX Identification Responses

The +FMI? command invokes the following information text.

	Hayes Microcomputer Products, Inc.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
FAX Commands in Data Mode

The only Class 1 command that is valid in data mode is +FCLASS.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Escape From On-line State

The FAX commands always return to command state after execution. 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

DTE Interface Speed
FAX Class 1 requires the DTE Interface speed to exceed the line speed.
See [1] 5.3 for details. Bi-directional flow control is used to regulate
the flow of data between the DTE and the DCE (modem).


************************************************************************
FAX Class 1

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
General

A FAX Class 1 DCE can establish calls, and can send and receive data
strings using one of several modulation and protocols. The DTE must
prepare all transmitted character strings and analyze all received data
strings. The DCE handles flags and frame check sequences when such are
required.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Commands

All of the Class 1 commands and responses defined in [1] are implemented
in Hayes FAX Class 1 modems.

Reference 1 includes V.17 and other modulations. If the modem does not
provide a modulation, then the modem returns the ERROR result code to
any command that invokes the missing modulation.

The value of register S86 is set to 1 if a hang-up occurs while the
modem is in the FAX mode.

FAX Class 1 action commands are valid only while the modem is off hook.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Answer Handshake

A Class 1 modem provides limited handshake capability. The modem goes
off hook and sends the V.21 signals specified in [1]. Answering may be
initiated by the A command or by the value of S0 exceeding 1 and ringing
being detected by the modem.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

FAE Automatic Data/FAX Handshake

Description             When the modem is configured for Class 1
                        operation (+FCLASS=1), the +FAE command may be
                        used to invoke automatic determination of data
                        or FAX incoming calls, and use of the DATA and
                        FAX result codes. The +FAE command is valid for
                        all +FCLASS values, but affect modem behavior
                        only when +FCLASS=1.

                        If +FAE=0, then incoming calls must be answered
                        by DTE commands and the modem do not use the FAX
                        or DATA result codes.

                        If +FAE=1 and the modem answers a call, the type
                        of calling station may be determined by
                        detection of calling tone or by probing during
                        handshake.

                        If it is determined that the calling station is
                        a FAX machine or modem, then the answering modem
                        sends flag idle signal (V.21 modulation) and
                        sends the FAX result code to the DTE. The DTE
                        then sends the appropriate Class 1 commands to
                        the modem to complete the call.
			
                        If it is determined that the calling station is
                        a data modem, the answering modem completes the
                        handshake, set +FCLASS=0, sends the DATA result
                        code to the DTE, and then sends the normal data
                        call result codes to the DTE to complete the
                        call setup.

                        If +FAE=1, then the silent period after an
                        answer modem goes off hook is 4 seconds instead
                        of the usual 2 seconds. This allows time to
                        detect a FAX calling tone before sending answer
                        tone.

                        +FAE is reset to value 0 when a Z or &F command
                        is executed.

Type			parameter command 

Value range 		0,1, Default value: 0 

Stored by &Wn	no 

Displayed by &V	no 

Values			+FAE=0 DATA/FAX discrimination disabled. 
			+FAE=1 DATA/FAX discrimination enabled.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Result Codes

Reference [1] names the following result codes, which can be used in numeric 
or verbose format.

Numeric 	Verbose 	Meaning 
-------------------------------------------------------------------------
0 		OK 		Ready for another command.
1 		CONNECT 	The modem is entering the data transfer state.
3               NO CARRIER      The modem is ready for a command; the
                                modem may not be on hook.
4               ERROR           Last command could not be executed;
                                modem is ready for another command.

The connect result code is always CONNECT without regard for the
modulation speed, which is selected by the DTE.

All other modem commands and result codes are allowed.

If the DCE detects a received tone different from that specified by a
+FRM or +FRH command, the DCE sends the result code +FCERROR to the DTE
and returns to command state. The numeric equivalent to +FCERROR is +F4.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Flow Control

Local DC1, DC3 flow control is always enabled if +FCLASS=1 and the modem
has a call established. In addition, if RTS is on when the command
+FCLASS=1 is issued, then RTS/CTS flow control is also invoked.

This procedure for managing flow control is used because FAX Class 1
specifies the use of DC1, DC3 flow control and allows other mechanisms,
but does not make any provision for selecting flow control. FAX Class 1
software does not use the &Kn commands.


*************************************************************************
Data Commands and Registers

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Commands

The &F command sets all data and FAX parameters to their Factory Default 

Values. The only parameter for Class 1 is +FCLASS; its default value is
0. You must set +FCLASS=1 to enable Fax Class 1 mode.

The Zn commands load the appropriate set of data parameters and do not
change any FAX parameters.

The &Wn commands store data parameters. FAX parameters are not stored;
most FAX programs send FAX parameters to a modem before using the modem
for a call.

All data commands (the commands that do not begin with +F) are valid
when the modem is in either data or FAX mode. However, the following
data configuration commands affect only the data mode.

Bn Cn Nn Yn &Bn &Gn &Mn &On &Qn &Rn &Un &Xn

When the modem is in the FAX mode (+FCLASS=1), the &Cn command invokes
the RLSD behavior associated with the &Q5 command.

The Mn command determines when the speaker is turned on and off. When in
the FAX mode, on until carrier means on until the initial CONNECT result
code for Class 1. The speaker is actually turned off within 5 ms before
or after the response is sent.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Special Call Setup Conditions

Leased Line - FAX modem operation on leased lines is not supported.

Reverse Modes - The &A command and R dial modifier are valid for FAX
calls.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
S-registers

The following S-registers do not affect the modem behavior while in the
FAX mode.

S18 S26 S30 S36 S37 S44 S45 S46 S48 S49 S50 S53 S55 S57 S69-S82 S84 
S93 S94 S95

Register S47 is set to 0 when the modem is online in the FAX mode. The
register normally indicates the type of data connection that has been
established.

Register S85 is set to 0 after a FAX call has been established.

Register S86 is set to 1 if a hangup occurs while the modem is in the
FAX mode. The value 1 is a new value for S86.

The modem does not accept V.25bis commands while in the FAX mode. Since
selection of the FAX mode requires use of an AT command, the modem has
to be in AT command mode before issuing the +FCLASS=1 command.

The HS light is on while the modem is in the FAX mode.

The SD and RD lights indicate DTE Interface activity, as they do in the
data mode.


**************************************************************************************************
References

1. "Asynchronous Facsimile DCE Control Standard (Class 1)", document
ANSI\EIA\TIA-578-1990.

2. "Standardization of Group 3 Facsimile Apparatus for Document
Transmission", CCITT Recommendation T.4, 1984.

3. "Facsimile Coding Schemes and Coding Control Functions for Group 4
Facsimile Apparatus", CCITT Recommendation T.6, 1988.

4. "Procedures for Document Facsimile Transmission in the General
Switched Telephone Network", CCITT Recommendation T.30, 1984.


=========================================================================
Chapter 10
Dumb Mode


*************************************************************************
General

A modem is often used in dumb mode to support specific applications,
especially synchronous applications, where the modem is powered-up and
utilized without asynchronous DTE equipment for control. The modem is
first configured in the Smart Mode using commands which are then stored
in a profile by the &Wn command.


*************************************************************************
Dumb Mode Characteristics

Dumb mode observes the following characteristics:

1.	The modem ignores all AT Commands.

2.	Keypress abort is disabled.

3.	Escape Sequences are ignored.

4.	Result Codes, Info-text, and any other non-user-data are suppressed.

5.      The CTS signal is not controlled by previous &Rn settings, but
        rather, operates more closely to the Industry Standard and ITU-T
        specifications for dumb modems as follows:

        a.      CTS is OFF until the modem is ready to pass user data.
                CTS then goes ON, and stays ON until the modem goes back
                on-hook. Exception: CTS is off during retrain and rate
                re-negotiation.

        b.      In Synchronous modes, the CTS signal follows the state
                of RTS. See also S26 for a definition of the amount of
                delay between RTS and CTS.

	c. 	In Asynchronous modes, CTS is not affected by RTS.

        d.      CTS is not affected by local or remote loopback test
                states, except to be off during retrain and rate
                re-negotiation.

6.	There is not an Online Command State.

7.      See &Dn description for dumb mode response to changes in state
        of DTR.

*************************************************************************
Making Calls

The modem answers calls while in dumb mode according to which &Qn
command is in effect and if register S0 was set to a non-zero value
(before entering dumb mode).

Note: Only OPTIMA modmes support dumb mode operation.

The modem originates calls when DTR goes ON if &Q2 has been selected, by
dialing the number associated with &Z0.

The modem goes off hook and starts originate handshake when DTR goes ON
if &Q3 has been selected.


************************************************************************
The Dumb Strap

You have movable jumpers or a DIP switch to select whether the modem
powers-up in Smart Mode or in Dumb Mode. The modem determines the mode
during a power up or reset.

Note: Only OPTIMA modems have a dumb strap.

Whenever the traditional Hayes Smartmodem enclosure design is used to
house a modem controlled by this specification, you are able to detach
the modem front cover and adjust the position of the dumb strap. Refer
to your modem's User Guide for the method to select this feature.


=========================================================================
Chapter 11
DTE Interface


*************************************************************************
General

The pin numbers mentioned below are for the 25-pin interface connector.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Clock Leads (pins 15, 17, 24)

Note: The Clock lead is available in OPTIMA products.

Transmit signal element timing (pin 15) and receive signal element
timing (pin 17) provide timing information to the DTE. Both leads are
OFF (marking state) unless &Q1-&Q3 is in effect and the modem is in the
Online or Online Command State. If &Q1-&Q3 and &X1 are in effect, the
transmit clock (pin 24) from the DTE provides the transmit clock source
while the modem is in the Online or Online Command State.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Clear to Send (CTS) - pin 5

Clear To Send indicates that the modem is ready to accept data from the
DTE for transmission to the remote modem.

If an OPTIMA modem is in the Dumb Mode, CTS is OFF in all states except
online state and comes ON at the end of the handshaking process.

If the modem is in the Smart Mode, CTS follows the rules described
below:

*	In the Idle, On-Line Command, and Analog Loopback States, CTS is ON.

*	In the Dialing and Handshaking States, and during the Answer Process:

*	CTS is ON if &Q0, &Q5, or &Q6 is in effect.

*	CTS is OFF if &Q2 or &Q3 is in effect.

*       If &Q1 or &Q4 is in effect, CTS is OFF if S0 is not zero and ON
        if S0 is zero.

*	In the on-line state:

*	If &Q0 is in effect, CTS is ON.

*       If &Q1 is in effect, CTS goes OFF when the online state is
        entered for the time specified by S25 (in seconds). Then CTS
        goes ON if &R1 is in effect and tracks RTS if &R0 is in effect.

*       If &Q2 or &Q3 is in effect, CTS is ON if &R1 is in effect and
        tracks RTS if &R0 is in effect.

*       If &Q4 is in effect CTS goes OFF for the time specified by S25
        (in seconds) when the online state is entered. Then CTS follows
        the Hayes AutoSync specification. Refer to the AutoSync
        specification 100-00085 for more information.

*       CTS goes OFF if carrier is lost from the remote modem and
        &Q1-&Q4 is in effect. It comes ON again when carrier is
        recovered if &R1 is in effect, or once RTS comes ON if &R0 is in
        effect.

*       If &Q5 or &Q6 is in effect, CTS is ON unless used for hardware
        flow control, which is selected by &K3.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Data Set Ready (DSR) - pin 6

Data Set Ready is an indicator of modem status to the DTE.

The &Sn commands select the behavior of DSR, except if the modem is 
operating in one of the synchronous modes or in AutoSync mode. 

If &Q1-&Q4 is in effect, DSR acts as if &S1 is in effect regardless of
the actual setting. DSR goes off if CD light goes off.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Data Terminal Ready (DTR) - pin 20

Data Terminal Ready is used for both call initiation, call termination,
suppressing Autoanswer, and initiating a hard reset. The modem's actual
response to DTR or a change in DTR depends on the &Dn and &Qn commands
in effect and may also depend on S25 and S94. Some modem functions are
affected by the level of DTR, while other functions may be affected by a
transition in DTR. Also, DTR may affect the TR indicator.

In addition to the information below, consult the &Dn and &Qn commands. 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
High Speed (HS) - pins 12 and 23

The High Speed leads both indicate the same state as the HS light. In
the Online Command or Idle States, HS is ON when the AT Speed is greater
than or equal to 4800 bits/second, and is off otherwise. In the online
state, HS is ON when the Line Speed is greater than or equal to 4800
bits/second, and is OFF otherwise. In the Handshaking State, HS may
change after the CONNECT result code is sent to the DTE.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Receive Data (RD) - pin 3

The received data lead conveys data from the modem to the DTE.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Ring Indicator (RI) - pin 22

Ring Indicator indicates the presence of a ringing signal on the
telephone line. When the modem is off hook or in an analog loopback test
(&T1 or &T8), RI is off. If the modem is in the idle state and a valid
ring signal is detected, RI comes on within 300 ms after initial signal
detection and remains on until no more than 50 ms after the signal
stops.

If &Q4 (Hayes AutoSync) is in effect, and the online state is active, RI
goes off when the end of frame byte has been transmitted and the
transmitter is entering the idle state. RI goes high when the DTE
(application) sends the next byte of data to the modem.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Received Line Signal Detector (RLSD) - pin 8

Received Line Signal Detector (RLSD) indicates the state of the remote
modem's received carrier according to the &Cn and &Qn commands in
effect. Refer to &Cn command definition in Chapter 4.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Request to Send (RTS) - pin 4

Request to Send, used to condition the modem for data transmission, is
ignored when the modem is in online command, idle, dialing, or
handshaking state. Once handshaking is complete and the online state is
reached, RTS is tracked (except during carrier recovery) and only if
&Q1-&Q3 is in effect, and &R0 is in effect. If RTS goes on, CTS is
turned on after the time delay specified by S26 (in 1/100 seconds) plus
a maximum of 10 ms. If RTS goes off, CTS is turned off immediately, plus
a maximum of 10 ms.

If &Q4 (Hayes AutoSync) is supported and in effect, and the modem is in
the on-line state, RTS is used to force the modem receiver to reset and
go into hunt mode. This is used in bisync (BSC) mode when the
application detects the end of frame.

RTS is ignored by the modem if one of the asynchronous DTE Interface
modes is selected (e.g., &Q0, &Q5, or &Q6).

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Send Data (SD) - pin 2

The send data lead conveys data from the DTE to the modem.


=========================================================================
Chapter 12
Modem LEDs


The information in this Chapter applies to Hayes external modems.


*************************************************************************
AA - Auto Answer

AA indicates the states of S-register S0 and the ringer detector system.
If S0=0, AA will be OFF while the absence of a ringer signal is
detected, and AA will be ON while a valid ringer signal is being
detected. If S0>0, AA is ON when no ring signal is detected, and AA is
OFF while a valid ringer signal has been detected. Refer to "Ring
Indicator" in Chapter 11.


*************************************************************************
CD - Carrier Detection

CD indicates the state of the modem's carrier detector system. CD is off
in the idle state. In the handshaking state, CD comes on after the
CONNECT result code is sent to the DTE. Once the online state is
entered, CD tracks detected carrier within 20 ms (LED ON means carrier
power detected).

CD is not affected by the value of S9 or the &Cn command. Refer to
"Carrier Detection" in Chapter 8.


*************************************************************************
HS - High Speed

HS and the HS leads of the DTE Interface (pins 12 and 23) indicate the
same state. In the Online Command or Idle States, HS is ON when the AT
Speed is greater than or equal to 4800 bits/second, and is off
otherwise. In the online state, HS is ON when the line speed is greater
than or equal to 4800 bits/second, and is OFF otherwise. In the
Handshaking State, HS may change after the CONNECT result code is sent
to the DTE.



*************************************************************************
MR - Modem Ready

MR indicates if a power up test fails or if a self test is currently
active. On power up, if the RAM read/write test fails, MR goes OFF and
the modem stops further activity. If RAM passes but the computed PROM
checksum is incorrect, MR attempts to flash at a rate of 853 ms ON, 853
ms OFF (+10%) while preventing additional activity. If both tests pass,
MR remains ON.

When a self test (&T1, &T3, &T6-&T8) is running, MR also flashes at the
above rate until the test is terminated and while the RDL process is
operating.


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OH - Off Hook

OH shows the state of the line relay. OH is off while the modem is on hook.


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RD - Receive Data

RD represents the serial data sent to the DTE from the modem over the RD
line (pin 3). RD is off when the signal represents a mark.


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SD - Send Data

SD represents the serial data sent to the modem from the DTE over the TD
line (pin 2). SD tracks the signal on Pin 2 of the DTE Interface within
1 ms. A mark signal on Pin 2 corresponds to the LED being off and SD is
off when the DTE is not sending characters to the modem.


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TR - Terminal Ready

TR indicates the state of the DTR line (pin 20). If &Q0 and &D0 are in
effect, TR remains on regardless of the state of DTR. Otherwise, TR
tracks the state of DTR. In the Idle State or Online Command State, TR
tracks DTR within 50 ms. While in the Online State, tracking is within
10 ms.


=========================================================================
Chapter 13
Relays


This chapter describes modem relay functionality.


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Line

The line relay is used to switch the modem on or off the telephone line.
When the relay contacts are closed, the modem is off hook. Otherwise it
is on hook. During pulse dialing, the line relay switches between the
open and closed states at a rate in effect by the &Pn option (select
make/break ratio).


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Phone

The phone relay is used to switch the modem's phone jack on or off the
telephone line. The relay contacts are closed while the modem is on
hook; opened while off hook.


