Table of Contents
Table of Contents:

Index

Copyright notice

Modem Help

Overview of the Modem

Features of the Modem

Class 1 and Class 2 Fax Transmission

Fax Features

Using the Modem

Using Your 56K Capable Modem

Setting Up Communication Programs that Use the Modem

Starting and Stopping the Modem

Using Calling Credit Cards with the Modem

AT Command Summary

Issuing AT Commands

Command Syntax Overview

Readme Information

QuickTests

Using the Country Selection Application

A to Z, and , ? =

A: Answer

B: Select Standard

C: Carrier Control

D: Dial

E: Echo

F: Online Echo

H: Hook Control

I: Info Request

L: Speaker Volume

M: Speaker Control

O: Online

P: Pulse Dial

Q: Quiet

S: Select Register

T: Tone Dial

V: Verbose Response

W: Connect Message Control

X: Extended Results

Y: Space Disconnect

Z: Software Reset

#UD: Unimodem Diagnostics

,: Wait

=: Set Register

?: Query Register

&amp.A to &amp.Z

C: Carrier Detect

D: DTR Options

F: Factory Defaults Command

G: Guard Tone

K: Set DTE Flow Control

L: Leased Line Mode

M:  Comm Mode

N: Force Speed

P: Pulse Ratio

Q: Comm Mode

S: DSR Options

U: Enable Trellis Coding

V: View Active Configuration and User Profiles

W: Write Configuration

Y: Select Stored Profile on Powerup Option

Z: Store Number

to , %A to %Z and "A to "Z

A: MNP Block Size for Stream Mode

B: Send Break

K: Break Control

L: MNP Data Mode

N: MNP and V.42 Negotiation Behavior

Q: Set DTE Flow Control

T: Set Timer

V: MNP Result codes

%A: Define Auto Fallback Character

%C: MNP Compression Control

%E: Fast Rate Renegotiation and Automatic Retrain

"H: V.42bis Compression Control

"N: V.42bis Dictionary Size

"O: V.42bis Maximum String Length

Other AT commands

+MS: Select Modulation

-SSE: Digital Simultaneous Voice Data (DSVD)

*TH: V.34 Data Rate Aggressiveness

#CID: CallerId

S-Register Summary

S0 - Ring Answer

S1 - Ring Count

S2 - Escape Character

S3 - Carriage Return Character

S4 - Line Feed Character

S5 - Backspace Character

S6 - Blind Dial Wait Time

S7 - Carrier Wait Time

S8 - Comma Wait Time

S9 - Carrier Accept Time

S10 - Lost Carrier Hang-Up Time

S11 - DTMF Dialing Speed

S12 - Escape Code Guard Time

S24 - Calling Tone

S25 - Hang-Up Delay on DTR Dropouts

S28 - Line Speed Control Register

S30 - Disconnect Inactivity Timer

S32 - XON Character

S33 - XOFF Character

S49 - V.34 Settings for Phase 1 (V.8)

S50 - V.34 Symbol Rates

S51 - V.34 Settings (Reserved)

S52 - V.34 Settings for Data Signaling

S52 - V.34 and 56K Settings for Data Signaling

S53 - V.34 Settings for Signal Processing (Technical Support)

S60 - A-law/mu-law Selection

Understanding Bit-Mapped S-Registers

Hints and Tips for Improved Performance

Blocks Received in Error with Zmodem File Transfer

Low Throughput When Transmitting or Receiving a File

MNP 5 Versus V.42bis Performance

MNP 4 versus V.42 Performance

Call Waiting

Seeing "Double"

Modem Messages and Codes

Modem User Error Messages

MWME0001

MWME0002

MWME0003

MWME0004

MWME0005

MWME0006

MWME0007

MWME0008

MWME0009

MWMI0001

Modem Status Indicators


Index
Index:

AA - Auto Answer Status Light Indicator

CD - Carrier Detect Status Light Indicator

Connect Status Indicator

Dialing Status Indicator

DTR - Data Terminal Ready Status Light Indicator

HS - High Speed Status Light Indicator

Indicator Lights

Lamps, Status

LEDs

Lights, Status

MR - Modem Ready Status Light Indicator

OH - Off Hook Status Light Indicator

RD - Receive Data Status Light Indicator

SD - Send Data Status Light Indicator

Status Lights


Copyright notice

 IBM Software. (c) Copyright IBM Corp. 1992, 1995. All rights reserved. Licensed Material - Property of IBM.

This online manual is copyrighted, and all rights are reserved.  No part of this manual or the products it describes may be reproduced by any means or in any form, without prior written consent in writing from IBM.


Modem Help

Overview of the Modem

Features of the Modem

Using the Modem

AT Command Summary

S-Register Summary

Hints and Tips for Improved Performance

Modem Messages and Codes

Modem User Error Messages

Modem Status Indicators


Overview of the Modem

Readme Information

Using the Country Selection Application

QuickTests

  Your modem is a fax and data modem that runs in the  Windows operating environments.

The modem adapter and software provide the modem function. The modem adapter supports direct attachment to public switched telephone networks (PSTN) and supports selected world wide countries.  Refer to the Country Selection Application for your current list of supported countries.

The modem also supports the standard COM port interface and is compatible with the Hayes** AT command set.


Features of the Modem

Fax Features

Class 1 and Class 2 Fax

The data modem provides the following features:

• Standard asynchronous COM port interface (NS16550A UART compatible) operation

• Bell-103/212A,CCITT-V.21/V.22, V.22bis protocols with data from 300 to 2400 bps

• CCITT-V.32 protocols with data rates of 4800, 9600 uncoded, and 9600 bps Trellis coded (Optional)

• CCITT -V.32bis protocols with data rates of 4800, 7200, 9600, 12000, and 14400 bps (Optional)

• ITU-T V.34 protocols with data rates from 2400 to 33600 bps

• 56K Capable Modem

• Hayes AT command set compatibility

• Call progress monitor

• Autodial

• Class 1 and Class 2 Fax

• DTMF and Pulse dialing

• Asynchronous error recovery protocol

• Error correction via Microcom Network Protocol** (MNP**) classes 1-4

• Error correction via the V.42 error correction standard

• MNP class 5 for up to 2x data compression

• "Adaptive Rate Negotiation" which provides for "Fallback/Fallforward" as line quality deteriorates or improves.

• V.42bis for up to 4x data compression

• Functional upgrades via software


Class 1 and Class 2 Fax Transmission

Your modem supports fax modem transfer using both Class 1 and Class 2 fax. Your fax application determines the class fax you need.

Class 1 fax relies more on the fax application for control.  However, the applications that use Class 1 often provide additional compression and error correction capabilities, which may result in faster fax transmissions.


Fax Features

 These features are provided to your Windows fax applications:

• Group 3 fax transfers-provides 200x200 and 200x100 resolutions

• T4 protocol-manages resolution, coding patterns, page size, and transmissi on time for Group 3 faxes

• T30 protocol-manages the fax session and negotiates the functions supported by connected faxes

• Transmission speeds up to 14400 bps using V.17 protocol

• Transmission speeds up to 9600 bps using V.29 protocol

• Transmission speeds up to 4800 bps using V.27ter protocol

• Class 1 fax transmission**

• Class 2 fax transmission**

• Support for Windows TAPI FAX application interface

• Manual SEND and  RECEIVE

Note: 	Facsimile Disclaimer: United States Telephone Consumer Protection Act of 1991 (Facsimile Devices)-The Telephone Consumer Protection Act of 1991 makes it unlawful for any person to use a computer or other electronic device to send any message via a telephone facsimile machine unless such message clearly contains, in a margin at the top or bottom of each transmitted page or on the first page of the transmission, the date and time it is sent and an identification of the business, other entity, or individual sending the message and the telephone number of the sending machine or such business, other entity, or individual.  To program this information into your facsimile, you should refer to the documentation which accompanies your FAX software package.


Using the Modem

Starting and Stopping the modem

Setting Up Communications Programs that Use the Modem

Using Calling Credit Cards with the  Modem

Using your 56K Capable Modem

You can use the modem with your communications program(s) to access your favorite bulletin board or online system (such as Prodigy**, Compuserve**, America Online**, and others).


Using Your 56K Capable Modem

Your Modem contains 56K technology (56000 bps).  To take advantage of your modem's 56K technology, you must first make sure that your Internet Service Provider (ISP) supports a 56K modem protocol.

1. Contact your Internet Service Provider (ISP) and determine which 56K modem protocol they use.

2. Determine which 56K modem protocol your modem supports.  To view your modem's supported protocol(s), do the following:

a.Click the Start button , select Programs  then select ThinkPad Modem .

b.Click Modem .

c.Choose Options  from the Modem Status Window then choose Settings .

d.The available transfer speeds are displayed.  The 56K protocol(s) your modem supports is listed in parenthesis following the 56000 bps transfer setting.

e.If no 56000 bps transfer setting is listed, your modem's 56K technology is not currently enabled.

3. Your modem and your Internet Service Provider (ISP) must support the same 56K modem protocol or your maximum connection speed will be limited to V.34 technology.

Significantly higher Internet modem connection speeds up to 56kbps require all-digital transmission connections from your Internet Service Provider (ISP) to the line card in the central office to which your phone line is connected.

The actual connection rate may be limited by the quality of your telephone lines which may vary from location to location.

Current regulations limit maximum transfer rates to 53K (53000 bps).  While your modem contains 56K technology, typical maximum connect rates in the receive direction may be significantly less that 56K.

Currently, 56K capability is in the receive direction only (from the Internet Service Provider to your local modem).  The transmit or send direction (from your local modem to the Internet Service Provider) uses V.34 technology.

Note:  56K transfer rates are not available in all locations or countries.  You must check with your Internet Service Provider to determine if your area supports 56K transfer rates.


Setting Up Communication Programs that Use the Modem

To use the modem with communications programs that access a bulletin board or online system, configure the communications program to use the communications port (COM1 or COM2) to access the modem.


Starting and Stopping the Modem

 The modem starts automatically when  a Windows operating system is started.   When you open any application that requires a fax or data modem for communication (for example, WinFax Pro for Windows), the modem consumes  DSP resources on your modem adapter.  When you close the communications application, the modem frees the resources for other applications to use.  When you exit the operating system in which it is running, the modem stops.

 While the modem is running, it is invisible and does not appear on the desktop or in the window list. To display the modem and view the status window, click the ThinkPad Modem folder and then double-click the [image] icon.

For more information about the indicators on the modem, see Modem Status Indicators.


Using Calling Credit Cards with the Modem

The data modem supports use of the calling credit cards issued by the  following companies:

Carrier  	Dialing Sequence

MCI** 	ATDT9w18008888000 $credit card number$telephone number

  	ATDT9w18002385030$telephone number$credit card number

Sprint** 	ATDT9w18008778000$telephone number$credit card number

GTE** 	ATDT9w0telephone number$credit card number

AT&T** 	ATDT9w18002255288,,,,1,,,,telephone number$credit card number


AT Command Summary

The following chapter lists all AT commands that the Modem understands.

Issuing AT Commands

Command Syntax Overview

A: Answer

B: Select Standard

C: Carrier Control

D: Dial

E: Echo

F: Online Echo

H: Hook Control

I: Info Request

L: Speaker Volume

M: Speaker Control

O: Online

P: Pulse Dial

Q: Quiet

S: Select Register

T: Tone Dial

V: Verbose Response

W: Connect Message Control

X: Extended Results

Y: Space Disconnect

Z: Software Reset

#UD: Unimodem Diagnostics

,: Wait

=: Set Register

?: Query Register

&C: Carrier Detect

&D: DTR Options

&F: Factory Defaults Command

&G: Guard Tone

&K: Set DTE Flow Control

&L: Leased Line Mode

&M: Comm Mode

&N: Force Speed

&P: Pulse Ratio

&Q: Comm Mode

&S: DSR Options

&U: Enable Trellis Coding

&V: View Active Configuration and User

&W: Write Configuration

&Y: Select Stored Profile on Powerup

&Z: Store Number

\A: MNP Block Size

\B: Send Break

\K: Break Control

\L: MNP Data Mode

\N: MNP and V.42 Negotiation Behavior

\Q: Set DTE Flow Control

\T: Set Timer

\V: MNP Result codes

%A: Define Auto Fallback Character

%C: MNP Compression Control

%E: Fast Rate Renegotiation Control

"H: V.42bis Compression Control

"N: V.42bis Dictionary Size

"O: V.42bis Maximum String Length

-SSE: Digital Simultaneous Voice Over Data (DSVD)

*TH: V.34 Data Rate Agressiveness


Issuing AT Commands

The modem is automatically started in the "command state."  and is  ready to accept AT commands.  The modem returns to "command" state  whenever a connection is broken.  This would be the case when the other  end hangs up or you issue an ATH0 command.

When a "D" (Dial) or "A" (Answer) command is processed, the modem enters the "online" state.  When in this state, all characters sent to the modem are transmitted to the computer at the other end of the phone line.

If you need to issue AT commands while in the "online" state, you can enter the sequence "+++".  The modem will respond with "OK" and you may enter AT commands.  The connection remains intact, but you are in "command" state.  To go back to "online" state, enter "ATO."

AT commands can be issued to the modem by starting a communications program.  Some programs allow AT commands to be issued to the modem only through AT command initialization strings (Prodigy software is an example).  Others  allow a dynamic dialog with the modem through a display window and the computer keyboard.  This dialog can be useful when debugging AT command initialization strings for software that does not automatically recognize the modem.


Command Syntax Overview

For each AT command, a syntax description will be given. In that description, the following conventions are used.

The command prefix is "AT". This is distinct from the command itself.

An ellipsis, "...", may be replaced by any valid command or command sequence.

"[CR]" is a carriage return.

A bold face "n", n, represents a numeric value. A table will follow the syntax description indicating valid values for "n".


Readme Information

The Readme includes last minute information about the adapter and system software.  The Readme also provides:

• Installation information

• Information about what to do before you call for help

Be sure to read the Readme before calling for help.


QuickTests

QuickTests is an application that:

• helps you determine if features are installed correctly

• helps you detemine if features are functioning correctly

QuickTests runs in Windows and tests the following features:

The Modem QuickTest takes the telephone off-hook, which verifies that the modem is correctly installed and that the phoneline is properly connected.


Using the Country Selection Application

The Country Selection Application controls the legal and functional operation of the modem hardware.  It is used to specify the Public Switched Telephone Network (PSTN) that the equipment is attached to and must be set to the correct country by the user.  This selection tells the modem how to correctly operate.  The user will be notified if a country is selected for which the modem does not have a matching configuration file.  In this case, how the user proceeds will depend on the legal requirements of the country.

Many countries require certification of equipment to be attached to the PSTN.  Information on these requirements can be obtained from the local telephone authority.  If the country you are in requires certification to attach to the PSTN and that country configuration is unavailable on your system, then you may not legally use the modem.

If the country you are in does not require certification, then you should select a country setting which best matches the operations of that telephone network.  In addition to meeting legal requirements, the Country Selection controls functional operations.  These include pulse dialing (rotary dialing) settings, ring detection, and tone recognition such as dial tone, busy tone, etc.  In general, the modem may be used for calling by using DTMF (tone) dialing and blind dialing.  Blind dialing refers to not waiting for dial tone before dialing which may be configured in the application you are using.


A to Z, and , ? =

This section contains details of the AT commands from A to Z, and also the commands , ? and =.


A: Answer

The A command causes the modem to begin the answer process.

Syntax: AT...A [CR]


B: Select Standard

Selects the communication standard (CCITT or BELL) used by the  modem at 1200 bps or below.

Syntax: AT...Bn...[CR]

n	Usage
0,NULL	CCITT standard
1	Bell standard


C: Carrier Control

The C command enables the transmit carrier.

Syntax: AT...C1...[CR]


D: Dial

The D command causes the modem to enter the dialing state.  The parenthesis, hyphen, and space characters may be added to the dialed number for clarity.  Any other characters following the D command that are not dial modifiers (represented by x) cause a command error.

Syntax:

 AT...D x[CR] AT...D x;...[CR]

x	Usage
0-9	Numeric dialing digits
A-Z	Alpha dialing digits
# *	Special dialing digits
P	Pulse dial
R	Force answer mode
S=n	Dial stored number n, where n=0-3.
T	DTMF dial
W	Wait for dial tone
,	Wait for time specified in register S8
!	Perform hook flash
@	Wait for quiet answer
;	Return to command state
$	Wait for calling card tone


E: Echo

The E command turns the command echoing ON and OFF.

Syntax: AT...En...[CR]

n	Usage
0,NULL	Turns command echoing off.
1	Turns command echoing on.


F: Online Echo

The F command control is used by some modems to determine whether characters are echoed to the DTE (i.e. the PC) while the modem is in the online state. Your modem does not support the F0 option. However, because the F command may be issued by older communications software, F1 is supported to assure backwards compatibility.

Syntax: AT...F1...[CR]

n	Usage
0,NULL	Online character echo enabled. Not supported, returns "ERROR".
1	Online character echo disabled. Only allowable value.


H: Hook Control

The H command causes the modem to take the line on-hook or offhook.

Syntax: AT...Hn...[CR]

n	Usage
0,NULL	Places the line on-hook (hangs up) and causes a transition to the off-line command state.
1	Takes the line off-hook and turns on the speaker control if enabled.


I: Info Request

The I command presents modem identification information.

Syntax: AT...In...[CR]

n	Usage
0,NULL	Returns the product code, which indicates the maximum line speed supported. When V.34 is the maximum supported, the product code is "28,800".  When V.32bis is the  maximum supported, the product code is "14,400".
1	Returns "OK".
2	Returns "OK".
3	Returns the modem identifier.  The format is "IBM  Modem vx.x", where x.x is the version number.
4	Returns the product name.


L: Speaker Volume

The L command controls the volume of the speaker output.

Syntax: AT...Ln...[CR]

n	Usage
0, NULL	Sets the speaker volume to the minimum level.
1	Sets the speaker volume to a low level.
2	Sets the speaker volume to a medium level.
3	Sets the speaker volume to a high level.


M: Speaker Control

The M command controls the operation of the speaker.

Syntax: AT...Mn...[CR]

n	Usage
0,NULL	Speaker is always off.
1,2	Sets the speaker on until the data carrier is present during the handshaking mode. Then it is turned off.
3	Sets the speaker off during dialing and then on until the data carrier is detected.


O: Online

The O command causes the modem to return to the online state for a previously established connection.

Syntax: AT...On[CR]

n	Usage
0,NULL	Causes the modem to return to the online state.


P: Pulse Dial

The P command causes the modem to use pulse dialing for all subsequent numbers.

Syntax: AT...P[CR]


Q: Quiet

The Q command controls the result codes generated by the modem.

Syntax: AT...Qn...[CR]

n	Usage
0,NULL	Enables result codes.
1	Disables result codes.


S: Select Register

The S command selects one of the modem internal registers for future operations. Also see  S-Register Settings, the = command and the ?. command.

Syntax:

 AT...S...[CR] AT...Sn...[CR]

Note: 	n must be one of the S-Register numbers listed under S-Register Settings.  If n is omitted, then "n=0" is assumed.


T: Tone Dial

The T command causes the modem to use DTMF (tone) dialing for all subsequent numbers.

Syntax: AT...T[CR]


V: Verbose Response

The V command controls the display of result codes.

Syntax: AT...Vn...[CR]

n	Usage
0,NULL	Result codes are returned as digits.
1	Result codes are returned as text messages.


W: Connect Message Control

This command controls the format of CONNECT messages.

Syntax: AT...Wn...[CR]

n	Usage
0,NULL	Upon Connection, the modem reports only the DTE Speed (e.g. CONNECT 115200)
1,2	Upon Connection, the modem reports only the DCE Speed (e.g. CONNECT 33600)


X: Extended Results

The X command enables the call progress tone detection capabilities and affects the associated result codes.

Syntax: AT...Xn...[CR]

n	Usage
0,NULL	Busy and dial tone detection are disabled. Result codes 0-4 are enabled.
1	Busy and dial tone detection are disabled. Result codes 0-4, and line speed reporting via the "CONNECT xxxx" messages are enabled.
2	Busy detection is disabled; dial tone detection is enabled. Result codes 0-4, 6, and linespeed reporting via the "CONNECT xxxx" messages are enabled.
3	Busy detection is enabled; dial tone detection is disabled. Result codes 0-4, 7, and linespeed reporting via the "CONNECT xxxx" messages are enabled.
4	Busy and dial tone detection are enabled. Result codes 0-4, 6-7, and linespeed reporting via the "CONNECT xxxx" messages are enabled.


Y: Space Disconnect

The Y command controls the long-space disconnect capabilities of the modem. If enabled (Y1), when a continuous BREAK of at least 1.6 seconds is received, disconnect from line (go on-hook). When ATH0 command is received or DTR goes low, generate a 4-second BREAK before going on-hook.

Syntax: AT...Yn...[CR]

n	Usage
0,NULL	Disables the long-space disconnect feature.
1	Enables the long-space disconnect feature.


Z: Software Reset

The Z command causes the modem to reload a stored profile.

Syntax: AT...Zn[CR]

n	Usage
0,NULL	Recall stored profile 0.
1	Recall stored profile 1.
2	Recall factory defaults (See &F)


#UD: Unimodem Diagnostics

This command is provided for compliance with the Microsoft Unimodem  Diagnostics Command Specification.  Please refer to the documentation  provided by Microsoft on the internet for information about this command.


,: Wait

The comma (,) command causes the modem to wait for the time specified by the contents of register S8 in seconds before processing any more characters in the command buffer.

Syntax: AT... , ...[CR]


=: Set Register

The = command is used to set the value of the modem's internal registers. Refer to  S-Register Settings for more detail. The = command is usually coupled with the Sn command and is invoked as follows:

AT...S3=13...[CR]

If the = command is not coupled with the Sn command, then the previously selected register will be written. Some registers cannot be written by the user. An "ERROR" message will result for these registers.

Syntax:

 AT...Sn=x...[CR] AT...=x...[CR]

Note: 	n must be one of the S-Register numbers listed under S-Register Settings.  x is a number from 0-255.


?: Query Register

The ? command is used to read the value of the modem's internal registers. Refer to S-Register Settings for more detail.

AT...S0?...[CR]

If the ? command is not coupled with the Sn command, then the previously selected register will be read.

Syntax:

 AT...Sn?[CR] AT...?...[CR]

Note: 	n must be one of the S-Register numbers listed under S-Register Settings.


&amp.A to &amp.Z

This section contains details of the AT commands from &A to &Z.


C: Carrier Detect

The &C command determines how the carrier detect signal is generated by the modem.  The carrier detect signal is present in the UART register, called the Modem Status Register.

Syntax: AT...&Cn...[CR]

n	Usage
0,NULL	The state of remote modem's carrier is ignored. The carrier detect flag is always on.
1	The state of the remote modem's carrier is detected by the modem and reflected by the state of the carrier-detect status bit in the Modem Status Register.


D: DTR Options

The &D command controls the modem's response to the Data Terminal Ready (DTR) control bit.

Syntax: AT...&Dn...[CR]

n	Usage
0,NULL	Ignores DTR.
1	Return to command state when ON-to-OFF transition is detected on DTR.
2	Hang-up, disable auto-answer, and return to command state when ON-to-OFF transition is detected on DTR.
3	Perform a software reset when ON-to-OFF transition is detected on DTR. The modem is reset and the profile, as specified in &Y, is loaded.


F: Factory Defaults Command

The &F extended command tells the modem to restore the factory default values into the internal registers and control variables.  The factory default values are identified in the S-register descriptions under S-Register Settings.

Syntax: AT...&F....[CR]


G: Guard Tone

The &G extended command controls the guard tone selection for the V.22bis datapump. The guard tones are generated during the handshaking process when the modem is in answer mode.

Syntax: AT...&Gn...[CR]

n	Usage
0,NULL	Disables the V.22bis guard tones.
2	Enables the 1800hz V.22bis guard tone.


K: Set DTE Flow Control

The &K command selects the flow control method that your modem provides to your Data Terminal Equipment (DTE). Flow control is used to prevent loss of data between a modem and a communications application when the PC or communications application cannot keep up with a high data rate in the receive direction or when the modem is not ready to send any more data.

DTE flow control is equivalent to using RTS (Request to Send) and CTS=RFS (Clear To Send = Ready For Sending) for flow control:

• In the receive direction, the communications program often drops  RTS to indicate to the modem that it cannot receive more data at that time. When RTS is dropped (off), the modem stops the data flow in the receive direction. When RTS is turned back on, the modem resumes the transmission of data to the communications program.

• CTS is used for flow control in the transmit direction; that is, the modem drops CTS to indicate to the communications program that it cannot send any more data and therefore cannot receive any more data from the communications program for the purpose of transmission.

Note: 	When using DTE flow control, dropping RTS causes the modem to stop the data flow in the receive direction only; data flow in the transmit direction is not affected.

Note: 	The &K command is mapped to the \Q command.

Syntax: AT...&Kn...[CR]

n	Usage
0,NULL	Flow control disabled.
1	Enables RTS/CTS hardware flow control.
2	Reserved
3	Enables RTS/CTS hardware flow control.
4	Enables XON/XOFF software flow control.
5	Enables transparent XON/XOFF software flow control.


L: Leased Line Mode

The modem is designed to work only on the public switched telephone network (PSTN). Support for leased line operation is not provided.

Syntax: AT...&Ln...[CR]

n	Usage
0,NULL	Selects switched-network line mode.


M:  Comm Mode

The &M extended command selects the communications mode. For your modem, only &M0 (asynchronous) mode is supported.

Syntax: AT...&Mn...[CR]

n	Usage
0,NULL	Selects asynchronous communications


N: Force Speed

The &N extended command controls the interpretation of register S28. This command applies only to V.34, V.32bis, and V.32. It is ignored by the V.22bis modem.

If &N1 is specified and S28 contains a non-zero value, then the modem will connect only at the speed specified by the S28 register. If this is not possible, the modem will hang up.

If &N1 is specified and S28 contains zero (S28=0), then the modem will connect only at the COM port speed specified by the UART, which is generally set by the communications application. If the COM port speed is set higher than the maximum supported line rate (for example, setting a port speed of 19200 bps while using the V.32bis modem which has a maximum line speed of 14400 bps), then the modem will connect at the maximum supported line rate.

Note: 	In case of V.34, &N1 enforces the same speed in transmit and receive directions.

Warning: 	Setting &N1 should be used for testing purposes only and only if the remote modem is forced to use the same speed. Note that the modem may encounter difficulty hanging up if &N1 is specified. If this happens, using ATH0 will cause the modem to hang up.

If &N0 is specified, the modem will connect with a transmit and receive data rate neither of which will exceed the line speed specified in register S28.

Syntax: AT...&Nn...[CR]

n	Usage
0,NULL	S28 specifies the maximum allowable data rate
1	S28 specifies the only allowable data rate (force speed)


P: Pulse Ratio

The &P command is present for compatibility purposes. It does not change the make/break ratios.

Syntax: AT...&Pn...[CR]

n	Usage
0,NULL	Returns "OK", but has no affect on timings.
1	Returns "OK", but has no affect on timings.


Q: Comm Mode

The &Q extended command selects the communications mode. For your modem, only &Q0 (asynchronous) mode is supported.

Syntax: AT...&Qn...[CR]

n	Usage
0,NULL	Selects asynchronous communications.


S: DSR Options

The &S extended command controls the operation of the DSR status bit. The DSR status is found in the UART Modem Status Register.

Syntax: AT...&Sn...[CR]

n	Usage
0,NULL	DSR is always ON while the modem is loaded.
1	DSR is turned on just after handshaking is completed and turned off when the hangup process is started.


U: Enable Trellis Coding

The &U extended command enables or disables the trellis coded data scheme in the V.32 and V.32bis modem. It has no affect on other datapumps. If issued while in online command state, it does not take affect until the next connection is established.

Syntax: AT...&Un...[CR]

n	Usage
0,NULL	Enable Trellis coding in V.32/V.32bis
1	Disable Trellis coding in V.32/V.32bis


V: View Active Configuration and User Profiles

The &V extended command displays active and stored profiles, and stored telephone numbers. Inputs from the DTE are ignored while the view information is being sent to the DTE.

Syntax: AT...&Vn...[CR]

Note: 	The format of the data output is as follows:

ACTIVE PROFILE

&Yn En Qn Vn \Vn P &Dn &Cn &Sn Yn Ln Mn Xn &G B &Un

\An \Kn \Ln \Nn &Kn \Tn %An %Cn %En "Hn "Nn "On

S0=nn S2=nn S3=nn S4=nn S5=nn S6=nn S7=nn

S8=nn S9=nn S10=nn S11=nn S12=nn S25=nn S28=nn

STORED PROFILE 0

En Qn Vn \Vn P &Dn &Cn &Sn Yn Ln Mn Xn &G B &Un

\An \Kn \Ln \Nn &Kn \Tn %An %Cn %En "Hn "Nn "On

S0=nn S2=nn S3=nn S4=nn S5=nn S6=nn S7=nn

S8=nn S9=nn S10=nn S11=nn S12=nn S25=nn S28=nn

STORED PROFILE 1

En Qn Vn \Vn P &Dn &Cn &Sn Yn Ln Mn Xn &G B &Un

\An \Kn \Ln \Nn &Kn \Tn %An %Cn %En "Hn "Nn "On

S0=nn S2=nn S3=nn S4=nn S5=nn S6=nn S7=nn

S8=nn S9=nn S10=nn S11=nn S12=nn S25=nn S28=nn

TELEPHONE NUMBERS

PHONE0=nn

PHONE1=nn

PHONE2=nn

PHONE3=nn


W: Write Configuration

The &W extended command saves the active modem configuration. The following registers are saved in nonvolatile storage: S0, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S14, S18, S21, S22, S23, S25, S27, S28. In addition, the following command parameters are stored: , , , , , %A, %C "Hn "Nn "On. The initial value of each of these profiles is defined by the &F command.

Syntax: AT...&Wn...[CR]

n	Usage
0,NULL	Store profile 0
1	Store profile 1


Y: Select Stored Profile on Powerup Option

The &Y extended command determines which stored profile is established upon modem power up or hard reset.

Syntax: AT...&Yn...[CR]

n	Usage
0,NULL	Select stored profile 0 on powerup.
1	Select stored profile 1 on powerup.
2	Select factory defaults on powerup.


Z: Store Number

The &Z extended command saves up to four separate phone numbers (dial strings) to permanent storage.  The &Z command may be followed by the dial string (75 character maximum) or be of the form &Zn=dial string, where n is in the range 0-3.  n is the identifier for the phone number to save. x is the dial modifier. This command may not be followed by additional commands.

Syntax:

 AT...Z &x[CR] AT...&Zn= x[CR]

x	Usage
0-9	Numeric dialing digits
A-D	Alpha dialing digits
# *	Special dialing digits
P	Pulse dial
R	Force answer mode
T	DTMF dial
W	Wait for dial tone
,	Wait for time specified in register S8
!	Perform hook flash
@	Wait for quiet answer
;	Return to command state after number is dialed


to , %A to %Z and "A to "Z

This section contains details of the AT commands from to , %A to %Z, and "A to "Z.


A: MNP Block Size for Stream Mode

The \A extended command sets the block size for MNP** stream mode.

Syntax: AT...\An...[CR]

n	Usage
0,NULL	Negotiates for a maximum block size of 64 bytes in receive direction and uses a fixed block size of 64 bytes in transmit direction.
1	Negotiates for a maximum block size of 256 bytes in receive direction, but uses a fixed block size of 128 bytes in transmit direction.
2	Negotiates for a maximum block size of 256 bytes in receive direction, but uses a fixed block size of 192 bytes in transmit direction.
3	Negotiates for a maximum block size of 256 bytes in receive direction, but uses a fixed block size of 256 bytes in transmit direction.
4	Negotiates for a maximum block size of 256 bytes in receive direction, but uses variable-size blocks in transmit direction (up to 256 bytes, so-called adaptive packet assembly).


B: Send Break

 The \B extended command causes the modem to transmit a break signal. This command is valid only in online command mode.

 Syntax: AT...\B...[CR]


K: Break Control

This command controls the actions to be taken by your modem upon reception of a break signal from either the DTE or from a remote modem.  The DTE may generate a break either through the UART hardware or by using the \B command.  Parameters 1-3 generate identical behavior for a non-ECL connection. The default is \K3.

Syntax: AT...\Kn...[CR]

n	Usage
0,NULL	When a break is received from the DTE and the modem is online, the modem escapes to command mode but a break is not sent to the the remote modem.  When a break is received from the remote modem, it is reported immediately and is nondestructive to any buffered data.
1	Breaks cause destruction of any buffered data, and they are reported immediately. The escaped state is not entered when a break is received from the DTE.
2	Breaks are nondestructive, and the break is reported immediately. The escaped state is not entered when a break is received from the DTE.
3	Breaks are nondestructive, and the break is queued in sequence with any buffered data and is reported in turn. The escaped state is not entered when a break is received from the DTE.


L: MNP Data Mode

The \L extended command selects a preference for stream mode or block mode operation during MNP** connections. In MNP negotiation, block mode takes precedence over stream mode. The mode may not be changed once an MNP session is established.

Syntax: AT...\Ln...[CR]

n	Usage
0,NULL	Preference for stream mode (variable block size based on \A command)
1	Preference for block mode (fixed block size of 260 bytes)


N: MNP and V.42 Negotiation Behavior

The \N extended command selects the MNP** and V.42 operational behavior.  Data compression is only possible when an ECL is established. MNP is capable of using either MNP Class 5 or V.42bis compression. V.42 is capable of using V.42bis compression only. V.42bis is controlled with the "H0 command. MNP Class 5 compression is controlled with the %C0 command. MNP and V.42 are both capable of operating without data compression.

Syntax: AT...\Nn...[CR]

n	Usage
0, 1, NULL	MNP** and V.42 are disabled.
2	Enables MNP, and only an ECL connection is acceptable.  If the MNP negotiations fail or the auto fallback character is received, then hang up.
3	Enables MNP and falls back to an non-ECL connection if the MNP negotiations fail or the auto fallback character is received.
4	Enables V.42 error correction, and only a V.42 ECL connection is acceptable. If the V.42 negotiations fail, then hang up.
5	Enables V.42 error correction, and falls back to a non-ECL connection if the V.42 negotiations fail.
6	Enables V.42 error correction, and falls back to an MNP connection if the V.42 negotiations fail.  If MNP negotiations fail, then hang up.
7	Enables V.42 error correction, and falls back to an MNP connection if the V.42 negotiations fail.  If the MNP negotiations fail or the auto fallback character is received, then fall back to a non-ECL connection.


Q: Set DTE Flow Control

The \Q command selects the flow control method that your modem provides to your Data Terminal Equipment (DTE). Flow control is used to prevent loss of data between a modem and a communications application when the PC or communications application cannot keep up with a high data rate in the receive direction or when the modem is not ready to send any more data.

DTE flow control is equivalent to using RTS (Request to Send) and CTS=RFS (Clear To Send = Ready For Sending) for flow control:

• In the receive direction, the communications program often drops  RTS to indicate to the modem that it cannot receive more data at that time. When RTS is dropped (off), the modem stops the data flow in the receive direction. When RTS is turned back on, the modem resumes the transmission of data to the communications program.

• CTS is used for flow control in the transmit direction; that is, the modem drops CTS to indicate to the communications program that it cannot send any more data and therefore cannot receive any more data from the communications program for the purpose of transmission.

Note: 	When using DTE flow control, dropping RTS causes the modem to stop the data flow in the receive direction only; data flow in the transmit direction is not affected.

Note: 	The \Q command is mapped to the &K command.

Syntax: AT...\Qn...[CR]

n	Usage
0,NULL	Flow control Disabled.
1	Returns ERROR
2	Returns ERROR
3	Enables RTS/CTS hardware flow control


T: Set Timer

 The \T extended command controls the operation of the inactivity timer.

Syntax: AT...\Tn...[CR]

n	Usage
0,NULL	The timer is disabled.
1-90	The timer is set to 1-90 minutes.


V: MNP Result codes

The \V extended command enables result codes of the form CONNECT xxxx/ECL.

Syntax: AT...\Vn...[CR]

n	Usage
0,NULL	Disables MNP** result codes.
1	Enables MNP result codes.


%A: Define Auto Fallback Character

The %A extended command defines a character to be used to abort the MNP** negotiation process.  The auto fallback character is a 7-bit character with no parity.  The auto fallback character should not be set to the ASCII SYN character (decimal 22).  This causes the MNP negotiation to be aborted for valid MNP frames.  The default is %A0, which disables the auto fallback feature.

 Syntax: AT...%An...[CR]

n	Usage
0-127	Defines the ASCII decimal code to be used as the auto fallback character by MNP.


%C: MNP Compression Control

 The %C extended command controls the data compression to be negotiated in MNP** class five. This command may be issued at anytime, but will only take effect at the establishment of the next connection.

Syntax: AT...%Cn...[CR]

n	Usage
0,NULL	No data compression.
1	Data compression is enabled for MNP** class five.


%E: Fast Rate Renegotiation and Automatic Retrain

Fast Rate Renegotiation and Automatic Retrain are mechanisms that allow two modems to respond to a change in line quality during a data connection. Rate renegotiation only requires the negotiation of new data rates. In contrast to retrain, rate renegotiation requires no retraining of the modem's receivers and is therefore much faster. Both rate renegotiation and retrain can be initiated by the call or answer modem. During a rate renegotiaton, a data rate can increase (fall forward) or decrease (fallback).

Note: 	 During a V.34 connection, the modem allows different data rates in transmit and receive directions (asymmetric data rates), provided the remote modem has the same capability; the V.32bis and V.32 Standards do not support asymmetric data rates.

The %E command controls the modem's response to a change in line quality and to requests for retrain or fallback/fall forward by the other end. This command affects only V.34, V.32bis, and V.32.

When line quality is insufficient to sustain the current connect speed, the modem initiates a fallback, provided that Fast Rate Renegotiation is enabled. If the latter is not the case, the modem initiates a retrain, provided that Automatic Retrain is enabled. If neither Fast Rate Renegotiation nor Automatic Retrain is enabled, the protocol layer may terminate the connection due to severe errors. The modem keeps falling back as needed until it reaches the lowest supported speed. If the line quality deteriorates further while connected at the lowest speed, the modem hangs up.

If the quality of the line increases, the modem may initiate a fall forward, if Fast Rate Renegotiation is enabled and the connection is either V.34 or V.32bis. Fall forward is not supported by the V.32 specification.

If a rate renegotiation is initiated by the remote modem, the modem responds with a rate renegotiation response, provided that rate renegotiation is enabled; otherwise, the modem responds with a retrain.

Syntax: AT...%En...[CR]

n	Usage
0,Null	Disable Fast Rate Renegotiation and Auto Retrain.
1	Disable Fast Rate Renegotiation and enable Auto Retrain.
2	Enable Fast Rate Renegotiation and Auto Retrain.


"H: V.42bis Compression Control

The "H extended command controls the data compression to be negotiated for with V.42bis.  This command may be issued at anytime but will only take effect on the next connection.

Syntax: AT..."Hn...[CR]

n	Usage
0,NULL	V.42bis Disabled
1	V.42bis enabled for transmission only
2	V.42bis enabled for reception only
3	V.42bis enabled for both transmission and reception


"N: V.42bis Dictionary Size

The "N extended command controls the dictionary size to be negotiated for with V.42bis.  This command may be issued at anytime, but will take effect only on the next connection.

Syntax: AT..."Nn...[CR]

n	Usage
0,NULL	512 Entries
1	1024 Entries
2	2048 Entries


"O: V.42bis Maximum String Length

The "O extended command controls the maximum string length to be negotiated for with V.42bis.  This command may be issued at anytime, but will take effect only on the next connection.

Syntax: AT..."On...[CR]

n	Usage
32,NULL	32 character maximum string length
6..250	6 to 250 character maximum string length


Other AT commands

This section contains details of commands not covered in preceding sections.


+MS: Select Modulation

The +MS command specifies the modulation to use in originating or answering a connection.

Syntax: AT...+MS=n

n	Modulation
3	V.23
11	V.34


-SSE: Digital Simultaneous Voice Data (DSVD)

The -SSE command controls the modem's Digital Simultaneous Voice Data (DSVD) function.  When this function is enabled, a call is placed (via ATDT) to another modem that is also enabled for DSVD, and a connection is established, the users can talk to each other over their microphone and speakers while still maintaining their normal data traffic.

Syntax: AT...-SSE[=]n...[CR]

n	Usage
0,NULL	Disable DSVD
1	Enable DSVD


*TH: V.34 Data Rate Aggressiveness

The *TH command determines a margin for the signal-to-noise ratio (SNR) in the V.34 modem. This margin affects the selection of line speeds of the V.34 modem. Increasing n by 1 requires an SNR improvement by 1 dB for the same data rate, unless the SNR is still high enough for that data rate.

If you experience difficulty connecting or staying connected, you may want to set n to a higher value to select a less aggressive data rate than for the default *TH4. A reduction of the line speed may in fact improve throughput, as there will be fewer packet errors during an ECL connection.

V.34 allows changing the SNR margin on the fly, that is, by issuing *TH commands from the online command state. This allows you to check the effect of the margin on throughput.

Example:  *TH7 sets the SNR margin 3 dB higher than the default setting, *TH4.

Syntax: AT *THn...[CR]

Range:  n=2...8


#CID: CallerId

The #CID command controls the CallerId function.  If you subscribe to CallerId services and the party calling you does not have CallerId blocked, the #CID command enables the modem to provide caller identification information.

Syntax: AT...#CID=n...[CR]

n	Usage
0	Disables CallerId (default)


S-Register Summary

Select the following for information about the internal S-registers, their default, range, units, and usage.

Note: 	Certain registers are bit-mapped. If a register is bit-mapped, it is so noted in the register description.

S0 - Ring Answer

S1 - Ring Count

S2 - Escape Character

S3 - Carriage Return Character

S4 - Line Feed Character

S5 - Backspace Character

S6 - Blind Dial Wait Time

S7 - Carrier Wait Time

S8 - Comma Wait Time

S9 - Carrier Accept Time

S10 - Lost Carrier Hang-Up Time

S11 - DTMF Dialing Speed

S12 - Escape Code Guard Time

S24 - Calling Tone

S25 - Hang-Up Delay on DTR Dropouts

S28 - Line Speed Control Register

S30 - Disconnect Inactivity Timer

S32 - XON Character

S33 - XOFF Character

S49 - V.34 Settings for Phase 1 (V.8)

S50 - V.34 Symbol Rates

S51 - V.34 Settings (Reserved)

S52 - V.34 and 56K Settings for Data Signaling

S53 - V.34 Settings for Signal Processing (Technical Support)

S60 - A-law/mu-law Selection


S0 - Ring Answer

Range :	0-255

Default :	0

Units :	Number of rings

Description:  S0 contains an integer representing the number of rings to allow before going off-hook (when in auto answer mode).  When S0 contains a non-zero value, the Modem DSP software is in auto answer mode.


S1 - Ring Count

Range :	0-255

Default :	0

Units :	Number of rings

Description:  S1 contains the ring count.


S2 - Escape Character

Range :	0-255

Default :	43

Units :	ASCII character

Description:  S2 contains the ASCII code for the escape character.  If S2 contains a value greater than 127, then the escape sequence is disabled.  The default 043 is the "+" character.


S3 - Carriage Return Character

Range :	0-127

Default :	13

Units :	ASCII Character

Description:  S3 contains the ASCII code for the carriage return.  The character contained in S3 is used for the command line terminator and for output line terminator.


S4 - Line Feed Character

Range :	0-127

Default :	10

Units :	ASCII Character

Description:  S4 contains the ASCII code for the line feed.  The character contained in S4 is used for the output line terminator for text output (V1).


S5 - Backspace Character

Range :	0-32

Default :	8

Units :	ASCII Character

Description:  S5 contains the ASCII code for the backspace character.  The character contained in S5 is used for editing an input line and is echoed back to the DTE to overwrite a character.


S6 - Blind Dial Wait Time

Range :	2-255

Default :	2

Units :	seconds

Description:  S6 contains the amount of time to wait (in seconds) after going off-hook, before dialing.  This allows time for dial tone to be applied to the line.


S7 - Carrier Wait Time

Range :	1-255

Default :	60

Units :	seconds

Description:  S7 contains the amount of time to wait for a data carrier.  If a carrier is detected, a "CONNECT" result is returned, otherwise a "NO CARRIER" result occurs.


S8 - Comma Wait Time

Range :	1-255

Default :	60

Units :	seconds

Description:  S8 contains the amount of time to wait for a comma command or dial modifier.


S9 - Carrier Accept Time

Range :	1-255

Default :	6

Units :	1/10 seconds

Description:  Carrier must be present for the amount of time specified in S9 before the modem will accept it. Increasing S9 lessens the chance of false carrier detect on noisy telephone lines.


S10 - Lost Carrier Hang-Up Time

Range :	1-255

Default :	14

Units :	1/10 seconds

Description:  S10 contains the amount of time to wait between loss of the carrier and hang-up.


S11 - DTMF Dialing Speed

Range :	50-255

Default :	95

Units :	milli-seconds

Description:  S11 contains the duration (ms) and inter-digit delay for DTMF tone dialing.


S12 - Escape Code Guard Time

Range :	0-255

Default :	50

Units :	1/50 seconds

Description:  The escape sequence for entering the online command state (usually "+++", see S2)  is recognized only if no data is sent from the communications program to the modem during a guard time before and after the escape sequence. The guard time is specified by S12.


S24 - Calling Tone

Range :	0-1

Default :	0

Units :	None

Description:  S24 enables/disables modem calling tone.  ATS24=1 enables tone, ATS24=0 disables tone. Enabling calling tone may make it easier for the modem you are calling to detect that this is a data call if the remote modem uses a voice/data/fax discriminator.


S25 - Hang-Up Delay on DTR Dropouts

Range :	0-255

Default :	5

Units :	1/100 seconds

Description:  S25 is the threshold time for accepting a DTR drop. DTR must stay off for the time in S25 before the modem will accept the off state. If DTR goes off and on again before the S25 timer expires (DTR dropout), the modem ignores DTR. The &D command determines the action the modem takes when "DTR off" is accepted.


S28 - Line Speed Control Register

Range :	0-50

Default :	0

Units :	None

Description:  S28 specifies the maximum line speed (data rate on telephone line) of the local modem. The line speed used will be the maximum speed supported by both modems not exceeding the speed specified by this register. For the V.34 modem, S28 limits the line speed in both transmit and receive directions. Line speeds are given in bits per second (bps). At speeds not exceeding 2400 bps (that is, for V.22bis or older modem protocols), the speed specified in S28 is the only possible speed.

Please note that the line speed depends on the choice of the modem protocol. For example, if V.32bis is selected in the Options Menu of the modem window or if the remote modem supports only V.32bis, speeds above 14400 bps will not be supported.

When the default setting &N0 is used, S28 is the maximum allowed line speed. When &N1 is used, however, S28 is the only allowed line speed.

Warning:  The setting &N1 (force speed) should  be used only for testing purposes and only if the remote modem is forced to use the same speed. For more information, see &N.

The following table provides the possible settings of S28 and the corresponding line speeds. For each speed, the possible modem protocols are listed in parentheses.

Value  	Maximum Line Speed (bps)

00 	The modem uses the COM port speed set by the communications application as the maximum line speed. The COM port speed is obtained from the UART divisor latch setting.

01-05 	Reserved.

06 	  300 bps (V.21)

07 	Reserved.

08 	 1200 bps (V.22bis/V.22)

09 	 2400 bps (V.22bis)

10 	 4800 bps (V.34/V.32bis/V.32)

11 	 7200 bps (V.34/V.32bis)

12 	 9600 bps (V.34/V.32bis/V.32)

13 	12000 bps (V.34/V.32bis)

14 	14400 bps (V.34/V.32bis)

15 	16800 bps (V.34)

16 	19200 bps (V.34)

17 	21600 bps (V.34)

18 	24000 bps (V.34)

19 	26400 bps (V.34)

20 	28800 bps (V.34)

21 	31200 bps (V.34)

22 	33600 bps (V.34)

23 	29333 bps (56kbps)

24 	30000 bps (56kbps)

25 	30666 bps (56kbps)

26 	32000 bps (56kbps)

27 	33333 bps (56kbps)

28 	34000 bps (56kbps)

29 	34666 bps (56kbps)

30 	36000 bps (56kbps)

31 	37333 bps (56kbps)

32 	38000 bps (56kbps)

33 	38666 bps (56kbps)

34 	40000 bps (56kbps)

35 	41333 bps (56kbps)

36 	42000 bps (56kbps)

37 	42666 bps (56kbps)

38 	44000 bps (56kbps)

39 	45333 bps (56kbps)

40 	46000 bps (56kbps)

41 	46666 bps (56kbps)

42 	48000 bps (56kbps)

43 	49333 bps (56kbps)

44 	50000 bps (56kbps)

45 	50666 bps (56kbps)

46 	52000 bps (56kbps)

47 	53333 bps (56kbps)

48 	54000 bps (56kbps)

49 	54666 bps (56kbps)

50 	56000 bps (56kbps)


S30 - Disconnect Inactivity Timer

Range :	0-540

Default :	0 (disabled)

Description:   S30 sets the length of time, in tens of seconds, that the modem remains connected when no data is sent or received.  The time resets when data is transmitted.  In error-correcting mode, received data also resets the timer.


S32 - XON Character

Range :	0-255

Default :	17

Description:   S32 sets the value of the XON character.


S33 - XOFF Character

Range :	0-255

Default :	19

Description:   S33 sets the value of the XOFF character.


S49 - V.34 Settings for Phase 1 (V.8)

Range :	n.a.

Default :	1

Description:  S-Register S49 (bit-mapped) contains settings for Phase 1 of the V.34 start-up. During this phase, which is specified in the ITU-T V.8 Recommendation, the two modems negotiate a layer-1 protocol such as V.34 or V.32bis. When the remote modem supports V.32bis only, the modem automatically selects the V.32bis protocol.

Value  	Bit     Description

01	Bit 0 - Disables V.8 call indicator.

02	Bit 1 - Disables V.8 protocol.

04	Bit 2 - Disables V.34 and V.32bis protocols.

08	Bit 3 - Disables V.34 protocol.

--	Bits 4 to 7 are reserved.


S50 - V.34 Symbol Rates

Range :	n.a.

Default :	0

Description:  The V.34 Standard supports 6 symbol rates (or modulation rates) from 2400 to 3429 symbols/second. In general, higher symbol rates allow higher line speeds (in bits/second). Based on measurements of your telephone channel, the V.34 modem automatically selects the symbol rate allowing the highest line speed. When a particular symbol rate is not suitable for reliable reception, it will automatically be disabled in the receive direction. As an example, some transatlantic connections do not provide enough bandwidth (in Hertz) for the highest symbol rates.

The modem also supports different symbol rates in the transmit and receive direction (asymmetric symbol rates).

By setting certain bits in the S50 register (bit-mapped),  you can manually disable individual symbol rates for reception. If asymmetric symbol rates are disabled, disabling a symbol rate for reception will also disable that symbol rate for transmission. In case of problems during the V.34 start-up (particulary when the local office is at a long distance from your telephone port), disabling of 3429 or 3200 symbols/second may help. Since the problem may be located in the remote modem, disabling a high symbol rate and at the same time disabling asymmetric symbol rates may solve the problem.

Value	Bit      Description
01	Bit 0 - Disables 2400 symb/s receive symbol rate.
02	Bit 1 - Disables 2743 symb/s receive symbol rate.
04	Bit 2 - Disables 2800 symb/s receive symbol rate.
08	Bit 3 - Disables 3000 symb/s receive symbol rate.
16	Bit 4 - Disables 3200 symb/s receive symbol rate.
32	Bit 5 - Disables 3429 symb/s receive symbol rate.
64	Bit 6 - Disables asymmetric symbol rates.
128	Bit 7 - Reserved.
Note:  These values are additive. For example, setting S50=16+32=48 disables reception at 3200 and 3429 Symb/second.


Asymmetric symbol rates allow the remote and local modems' receivers to independently choose their optimum receive symbol rates.


S51 - V.34 Settings (Reserved)

Range :	n.a.

Default :	0

Description:  Reserved.


S52 - V.34 Settings for Data Signaling

Range :	n.a.

Default :	2

Description:  S52 (bit-mapped) controls certain modes of V.34 data transmission.  The V.34 Standard allows different line speeds in transmit  and receive direction. (asymmetric data rates).

Value	Bit      Description
01	Bit 0 - Disables asymmetric data rates for V.34.
02	Bit 1 - Disables auxiliary channel for V.34.
04	Bit 2 - Disables V.34 data rates above 28.8 kbps
	Bit 3 - Reserved
	Bits 4-7 - Reserved


S52 - V.34 and 56K Settings for Data Signaling

Range :	n.a.

Default :	2

Description:  S52 (bit-mapped) controls certain modes of V.34 and 56K data transmission.  The V.34 Standard allows different line speeds in transmit  and receive direction. (asymmetric data rates).

Value	Bit      Description
01	Bit 0 - Disables asymmetric data rates for V.34.
02	Bit 1 - Disables auxiliary channel for V.34.
04	Bit 2 - Disables V.34 data rates above 28.8 kbps
	Bit 3 - Reserved
16	Bit 4 - Disables use of proprietary interface for 56Kbps operation
32	Bit 5 - Disables use of the V.90 interface for 56Kbps operation
	Bits 6-7 - Reserved


Asymmetric data rates (or line speeds) allow the remote and local modems' receivers to independently choose their optimum receive data rates.


S53 - V.34 Settings for Signal Processing (Technical Support)

Range :	n.a.

Default :	0

Description:  The appropriate signal processing functions are selected automatically by the V.34 modem. However, it may sometimes be useful (for example, when trouble-shooting) to disable certain functions. You can disable functions manually by setting bits in the  (bit-mapped) S53 register. Please note that setting one of bits 0 to 4 disables the corresponding function in receive direction only. In other words, bits 0 to 4 affect the transmit signal of the remote V.34 modem.

Value	Bit     Description
01	Bit 0 - Disable requests for power reduction.
02	Bit 1 - Disable requests for strong pre-emphasis.
04	Bit 2 - Disable requests for (non-linear) constellation warping.
08	Bit 3 - Disable requests for constellation shaping.
16	Bit 4 - Disable requests for trellis-enhanced precoding.
	Bits 5-7 - Reserved


S60 - A-law/mu-law Selection

Range :	0-1

Default :	Based on current country selection

Units :	None

Description:  Different countries provide different analog-to-digital and digital-to-analog line conversion methods for their telephone networks. Your modem has been configured to use the most common type for your country. If you are having difficulty establishing a 56k connection when you are calling a 56k-enabled Internet Service Provider, you may want to try changing this value.  You can query the value in this register to determine the default type for the currently selected country. Please note that there are many other possible and more likely causes for having difficulty establishing 56k connections. Please read the Using Your 56k Capable Modem section of the Modem Help for more information.

Value	Description
0	mu-law
1	A-law


Understanding Bit-Mapped S-Registers

S-registers have a width of 8 bits (1 byte). Hence, they can assume values between 0 and 127 decimal. Certain S-registers are bit-mapped; that is, each of the 8 bits of an S-register can be individually turned on (1) or off (0). Bit 0 is always the least significant bit and bit 7 is the most significant bit (Hayes** and PC notation). Each of the 8 bit positions has a corresponding decimal value. The desired value for a bit-mapped S-register is obtained by adding up the decimal values corresponding to all bits to be turned on.

Example   When you set S50=32, bit 5 (value 32) is turned on and the 3429 Symb/second receive symbol rate of the V.34 modem is disabled. When you want to turn on several bits, the corresponding decimal values can be added up. For example, S50=32+64=96 disables 3429 Symb/second (bit 5, value 32) and asymmetric symbol rates (bit 6, value 64).


Hints and Tips for Improved Performance

For hints and tips about the modem, select the following:

 Blocks Received in Error with Zmodem File Transfer

 Low Throughput When Transmitting or Receiving a File

 MNP 5 Versus V.42bis Performance

 MNP 4 versus V.42 Performance

 Call Waiting

 Seeing "Double"

 Using Calling Credit Cards with the Modem


Blocks Received in Error with Zmodem File Transfer

Normally with an error correcting protocol like MNP 4 or V.42, a user would expect that no frame would be received in error when using a file transfer protocol like Zmodem or Ymodem.  However, the modem can be delivering data to the PC so fast that it overruns buffers in the PC and makes it appear to Zmodem that a data block has been received in error.

You can solve the problem by getting a more efficient communications program or a faster PC.  You can also solve the problem by using flow control.  Set your application to use hardware flow control and then use the "AT" command to turn on flow control in the modem.  The advantage of flow control is that it can compensate for slow or overloaded PCs and for inefficient applications and will guarantee no data is lost.  The disadvantage is that you may receive data at a slower rate because the modem is forced to wait on the PC and the communications software.

If you use hardware flow control, ensure that you set your PC communications program to use hardware flow control.


Low Throughput When Transmitting or Receiving a File

In your PC the UART (Universal Asynchronous Receiver Transmitter) is the piece of hardware that connects your PC to your modem. Communications software talks to a communications driver that in turn talks to the UART hardware.

If you are experiencing throughput problems, a driver of this type may improve the situation for all operations at 14,400 bps (also know as V.32bis) or higher.


MNP 5 Versus V.42bis Performance

If you are getting an MNP5 connection, and you are transferring already compressed files (such as "ZIP" files), you can improve performance by disabling MNP5 with the "AT%C0" command.  MNP5 will expand compressed files and will slow down throughput.  V.42bis will not slow down throughput for any kind of file transfer.

You can disable MNP 5 with the "AT%C0" command.


MNP 4 versus V.42 Performance

Use MNP4 instead of V.42 to improve throughput.  The MNP4 protocol is 2% more efficient than the V.42 protocol.  The advantage of V.42 over MNP is that it can do selective packet rejection.  Your modem currently does not support selective packet rejection. Thus, for your modem, MNP 4 is always a marginally better performer.


Call Waiting

Many local telephone companies offer a "Call Waiting" service that informs you when a call is coming in when you are already using the phone line. You normally hear a "beep" in the middle of a conversation.

This service can cause the modem to have low throughput, errors, and even to disconnect.  When using the modem, disable call waiting. Contact your local phone company to determine how to disable call waiting.  However, it is generally done on a "per call" basis by preceding your dialing digits with the digits "*70".  So, if you want to set up a dialing string that also disables call waiting, try "ATDT*70,,555-1212" where "555-1212" is the number of the remote computer you wish to connect with. The commas between "*70" and "555-1212" cause the dialer to pause a few seconds to ensure the line is ready for the rest of the dialing digits.


Seeing "Double"

When the commands and words you type appear twice or "double", change the setup of your communications program.  Turn "local echo" off or set it for "full duplex mode".  See the manual for your communications program for instructions.


Modem Messages and Codes

The results from executed AT commands and status from the Modem DSP software are reported to the host communications software as result codes and text messages.  Reporting of the result codes is controlled by the Q command and the result code format is controlled by the V command.  The X command and the  command control which result codes will be used.

The following table provides a summary the numeric and text result codes generated by the AT command set.

Number	Text Form and Explanation
0	OK. Acknowledges the execution of a command.
1	CONNECT. Indicates that a connection has been established with a remote modem at a speed of 0-600 bps.
2	RING.  Indicates that an incoming call has been detected.
3	NO CARRIER. Indicates a failure to connect (handshaking state) or a loss of carrier (online state).
4	ERROR. Indicates an error condition in the command buffer being executed. Possible causes include 1) Invalid command sequence entered or 2) Command line too long (exceeds 40 characters).
5	CONNECT 1200. Indicates that a connection has been established with a remote modem at a speed of 1200 bps.
6	NO DIALTONE. Indicates that dial tone detection was attempted but not recognized. Enabled by X2 and X4.
7	BUSY. Indicates that a busy signal was detected during the call establishment.  Enabled by X2 and X4.
8	NO ANSWER. Indicates that the required period of silence was not detected during the "wait for quiet answer" timeout period specified by modem register S7.  This occurs when an @ dial modifier is used.
10	CONNECT 2400. Indicates that a connection has been established with a remote modem at a speed of 2400 bps.
15	HOST DRIVER TIMEOUT. Indicates that the PC is not responding to interrupts from the modem adapter.
16	NO ACTIVITY. Sets the length of time, in tens of seconds, that the modem will stay online before disconnecting when no data is sent or received. In synchronous mode, the timer is inoperative.
19	CONNECT ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42.
20	CONNECT ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42.
24	DELAYED. Indicates that a connection has been delayed.
25	CONNECT 1200/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 1200 bits per second.
26	CONNECT 1200/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 1200 bits per second.
30	CONNECT 2400/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 2400 bits per second.
31	CONNECT 2400/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 2400 bits per second.
32	BLACKLISTED. Valid only outside the US and Canada.  Indicates that no further call to this number are allowed.
33	CONNECT 4800. Indicates that a connection has been established with a remote modem at a speed of 4800 bps.
34	CONNECT 4800/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 4800 bits per second.
35	CONNECT 4800/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 4800 bits per second.
37	CONNECT 7200. Indicates that a connection has been established with a remote modem at a speed of 7200 bps.
38	CONNECT 7200/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 7200 bits per second.
39	CONNECT 7200/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 7200 bits per second.
41	CONNECT 9600. Indicates that a connection has been established with a remote modem at a speed of 9600 bps.
42	CONNECT 9600/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 9600 bits per second.
43	CONNECT 9600/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 7200 bits per second.
45	CONNECT 12000. Indicates that a connection has been established with a remote modem at a speed of 12000 bps.
46	CONNECT 12000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 12000 bits per second.
47	CONNECT 12000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 12000 bits per second.
49	CONNECT 14400. Indicates that a connection has been established with a remote modem at a speed of 14400 bps.
50	CONNECT 14400/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 14400 bits per second.
51	CONNECT 14400/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 14400 bits per second.
53	CONNECT 16800. Indicates that a connection has been established with a remote modem at a speed of 16800 bps.
54	CONNECT 16800/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 16800 bits per second.
55	CONNECT 16800/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 16800 bits per second.
57	CONNECT 19200. Indicates that a connection has been established with a remote modem at a speed of 19200 bps.
58	CONNECT 19200/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 19200 bits per second.
59	CONNECT 19200/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 19200 bits per second.
61	CONNECT 21600. Indicates that a connection has been established with a remote modem at a speed of 21600 bps.
62	CONNECT 21600/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 21600 bits per second.
63	CONNECT 21600/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 21600 bits per second.
64	CONNECT 24000. Indicates that a connection has been established with a remote modem at a speed of 24000 bps.
65	CONNECT 24000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 24000 bits per second.
66	CONNECT 24000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 24000 bits per second.
67	CONNECT 26400. Indicates that a connection has been established with a remote modem at a speed of 26400 bps.
68	CONNECT 26400/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 26400 bits per second.
69	CONNECT 26400/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 26400 bits per second.
71	CONNECT 28800. Indicates that a connection has been established with a remote modem at a speed of 28800 bps.
72	CONNECT 28800/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 28800 bits per second.
73	CONNECT 28800/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 28800 bits per second.
74	CONNECT 29333. Indicates that a connection has been established with a remote modem at a speed of 29333 bps.
75	CONNECT 29333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 29333 bits per second.
76	CONNECT 29333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 29333 bits per second.
77	CONNECT 30000. Indicates that a connection has been established with a remote modem at a speed of 30000 bps.
78	CONNECT 30000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 30000 bits per second.
79	CONNECT 30000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 30000 bits per second.
80	CONNECT 30666. Indicates that a connection has been established with a remote modem at a speed of 30666 bps.
81	CONNECT 30666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 30666 bits per second.
82	CONNECT 30666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 30666 bits per second.
83	CONNECT 31200. Indicates that a connection has been established with a remote modem at a speed of 31200 bps.
84	CONNECT31200/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 31200 bits per second.
85	CONNECT 31200/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 31200 bits per second.
86	CONNECT 32000. Indicates that a connection has been established with a remote modem at a speed of 32000 bps.
87	CONNECT 32000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 32000 bits per second.
88	CONNECT 32000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 32000 bits per second.
89	CONNECT 33333. Indicates that a connection has been established with a remote modem at a speed of 33333 bps.
90	CONNECT 33333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 33333 bits per second.
91	CONNECT 33333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 33333 bits per second.
92	CONNECT 33600. Indicates that a connection has been established with a remote modem at a speed of 33600 bps.
93	CONNECT 33600/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 33600 bits per second.
94	CONNECT 33600/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 33600 bits per second.
95	CONNECT 34000. Indicates that a connection has been established with a remote modem at a speed of 34000 bps.
96	CONNECT 34000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 34000 bits per second.
97	CONNECT 34000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 34000 bits per second.
98	CONNECT 34666. Indicates that a connection has been established with a remote modem at a speed of 34666 bps.
99	CONNECT 34666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 34666 bits per second.
100	CONNECT 34666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 34666 bits per second.
101	CONNECT 36000. Indicates that a connection has been established with a remote modem at a speed of 36000 bps.
102	CONNECT 36000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 36000 bits per second.
103	CONNECT 36000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 36000 bits per second.
104	CONNECT 37333. Indicates that a connection has been established with a remote modem at a speed of 37333 bps.
105	CONNECT 37333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 37333 bits per second.
106	CONNECT 37333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 37333 bits per second.
107	CONNECT 38000. Indicates that a connection has been established with a remote modem at a speed of 38000 bps.
108	CONNECT 38000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 38000 bits per second.
109	CONNECT 38000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 38000 bits per second.
110	CONNECT 38666. Indicates that a connection has been established with a remote modem at a speed of 38666 bps.
111	CONNECT 38666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 38666 bits per second.
112	CONNECT 38666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 38666 bits per second.
113	CONNECT 40000. Indicates that a connection has been established with a remote modem at a speed of 40000 bps.
114	CONNECT 40000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 40000 bits per second.
115	CONNECT 40000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 40000 bits per second.
116	CONNECT 41333. Indicates that a connection has been established with a remote modem at a speed of 41333 bps.
117	CONNECT 41333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 41333 bits per second.
118	CONNECT 41333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 41333 bits per second.
119	CONNECT 42000. Indicates that a connection has been established with a remote modem at a speed of 42000 bps.
120	CONNECT 42000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 42000 bits per second.
121	CONNECT 42000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 42000 bits per second.
122	CONNECT 42666. Indicates that a connection has been established with a remote modem at a speed of 42666 bps.
123	CONNECT 42666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 42666 bits per second.
124	CONNECT 42666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 42666 bits per second.
125	CONNECT 44000. Indicates that a connection has been established with a remote modem at a speed of 44000 bps.
126	CONNECT 44000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 44000 bits per second.
127	CONNECT 44000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 44000 bits per second.
128	CONNECT 45333. Indicates that a connection has been established with a remote modem at a speed of 45333 bps.
129	CONNECT 45333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 45333 bits per second.
130	CONNECT 45333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 45333 bits per second.
131	CONNECT 46000. Indicates that a connection has been established with a remote modem at a speed of 46000 bps.
132	CONNECT 46000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 46000 bits per second.
133	CONNECT 46000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 46000 bits per second.
134	CONNECT 46666. Indicates that a connection has been established with a remote modem at a speed of 46666 bps.
135	CONNECT 46666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 46666 bits per second.
136	CONNECT 46666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 46666 bits per second.
137	CONNECT 48000. Indicates that a connection has been established with a remote modem at a speed of 48000 bps.
138	CONNECT 48000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 48000 bits per second.
139	CONNECT 48000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 48000 bits per second.
140	CONNECT 49333. Indicates that a connection has been established with a remote modem at a speed of 49333 bps.
141	CONNECT 49333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 49333 bits per second.
142	CONNECT 49333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 49333 bits per second.
143	CONNECT 50000. Indicates that a connection has been established with a remote modem at a speed of 50000 bps.
144	CONNECT 50000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 50000 bits per second.
145	CONNECT 50000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 50000 bits per second.
146	CONNECT 50666. Indicates that a connection has been established with a remote modem at a speed of 50666 bps.
147	CONNECT 50666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 50666 bits per second.
148	CONNECT 50666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 50666 bits per second.
149	CONNECT 52000. Indicates that a connection has been established with a remote modem at a speed of 52000 bps.
150	CONNECT 52000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 52000 bits per second.
151	CONNECT 52000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 52000 bits per second.
152	CONNECT 53333. Indicates that a connection has been established with a remote modem at a speed of 53333 bps.
153	CONNECT 53333/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 53333 bits per second.
154	CONNECT 53333/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 53333 bits per second.
155	CONNECT 54000. Indicates that a connection has been established with a remote modem at a speed of 54000 bps.
156	CONNECT 54000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 54000 bits per second.
157	CONNECT 54000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 54000 bits per second.
158	CONNECT 54666. Indicates that a connection has been established with a remote modem at a speed of 54666 bps.
159	CONNECT 54666/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 54666 bits per second.
160	CONNECT 54666/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 54666 bits per second.
161	CONNECT 56000. Indicates that a connection has been established with a remote modem at a speed of 56000 bps.
162	CONNECT 56000/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 56000 bits per second.
163	CONNECT 56000/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 56000 bits per second.
170	CONNECT 38400. Indicates that a connection has been established with a remote modem at a speed of 56000 bps.
171	CONNECT 38400/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 56000 bits per second.
172	CONNECT 38400/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 56000 bits per second.
173	CONNECT 57600. Indicates that a connection has been established with a remote modem at a speed of 56000 bps.
174	CONNECT 57600/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 56000 bits per second.
175	CONNECT 57600/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 56000 bits per second.
176	CONNECT 115200. Indicates that a connection has been established with a remote modem at a speed of 56000 bps.
177	CONNECT 115200/ECL. Indicates that a connection has been established with an error correcting link using MNP or V.42 at 56000 bits per second.
178	CONNECT 115200/ECLC. Indicates that a connection has been established with an error correcting link, with data compression, using MNP or V.42 at 56000 bits per second.


Modem User Error Messages

In the case of a modem failure, one or more of the following error messages and other information needed by IBM in diagnosing the problem will be found in the MWMERROR.LOG file located in the \MWW\MODEM subdirectory

For more information about the Modem user error messages, select the following:

MWME0001

MWME0002

MWME0003

MWME0004

MWME0005

MWME0006

MWME0007

MWME0008

MWME0009

MWMI0001


MWME0001

Explanation:  Modem Internal Error.

Response:  Record the information in the error dialog box and report it to the service contact listed in your installation manual.


MWME0002

Explanation:  The modem phone line is already in use.

Response:  Another application is currently using the phone line.  If the modem ended prematurely due to a trap, this error might be encountered.  In this case, reboot (restart) the operating system in which the modem is running (Windows) and try again.


MWME0003

Explanation:  The phone handset is already in use.

Response:  Another application is currently using the handset.  If the modem ended prematurely due to a trap, this error might be encountered.  In this case, reboot (restart) the operating system in which the modem is running (Windows) and try again.


MWME0004

Explanation:  The Communications port is already in use.

Response:  Another application is currently using the COM port.  If the modem ended prematurely due to a trap, this error might be encountered.  In this case, reboot (restart) the operating system in which the modem is running (Windows) and try again.


MWME0005

Explanation:  The DSP is overcommitted.

Response:  Stop an application (such as MIDI) and restart the modem.  There are not enough resources available on the DSP to fulfill the request.


MWME0006

Explanation:  The modem cannot locate the needed DSP files.

Response:  Make sure the MWPATH environment variable under Control Panel/System  contains the path to all of the modem DSP files.


MWME0007

Explanation:  The specified modem speed/protocol is not installed.

Response:  In order to start this modem speed, the user must purchase an upgrade.


MWME0008

Explanation:  The Manager is not loaded.

Response:  Start the Manager Daemon, then try to start the modem.


MWME0009

Explanation:  Selected Country Does Not Match the DAA Coupler.

Response:  The modem has detected that the country specified in the Country Selection application does not match the DAA (external coupler) connecting your machine to the phone line. Make sure that the country selected matches the installed coupler.


MWMI0001

Explanation:  Modem Help is not available.

Response:  The modem cannot find the MWMWIN.HLP help file.


Modem Status Indicators

The following provides information about the status indicators on The modem window.

Indicator  	Description

MR 	Indicates that the modem is loaded and operational. This light should be on at all times after the modem is initialized.

DTR 	Usually indicates that a communications application is active.

SD 	Indicates that the modem is transferring data from your computer to the remote system.  When data is being transferred at fast data rates, this light may appear to be ON steadily.

RD 	Indicates that the modem is transferring data from the remote system to your computer.  When data is being transferred at fast data rates, this light may appear to be ON steadily.

OH 	Indicates that the modem phone line is off-hook (in use).

CD 	When ON, the modem has detected a remote modem's carrier signal.

AA 	Indicates that the modem is set up to automatically answer incoming calls.

HS 	Indicates that the modem is set up to connect at a line speed greater than 2400 bps.

In addition to the status indicators, the modem user interface provides status about the state of the connection to the remote modem. The following states are indicated on the user interface:

Ready  	No connection exists.

Dialing  	A dial command has been issued, but a connection has not been completed.

Negotiating  	The remote modem has answered and the modems are attempting to negotiate a connection.

Connect  	The two modems have completed negotiation and a connection has successfully been achieved.

When the status is Connect, additional status about the connection is given. The values given are:

Speed  	The line speed of the connection.  Typically this is 46666, 45333, 44000, 41333, 40000, 38666, 36000, 32000, 30666, 33600, 28800, 14400, 9600, 2400, 1200 or 300 bits per second.

Protocol  	V.34, V.32bis or V.22bis, V.80

Error Correction  	MNP, V.42 or blank (for an asynchronous connection)

Compression  	MNP 5, V.42bis or blank for no compression


Modem Ready


Data Terminal Ready


Send Data


Receive Data


Off Hook


Carrier Detect


Auto Answer


High Speed


Discrimination is the process of monitoring an incoming telephone call to determine whether the call is destined for a voice application, a data modem application, or a fax modem application.


Peripheral hardware refers to devices attached to the DSP to provide functions such as switching capability or signal conversion.


A digital signal processor (DSP) is a special-purpose microprocessor designed specifically to handle processing of real-time signals.


A DSP task is a program running in the DSP under Modem/OS that performs a particular function or process.  Multiple tasks may be run on the DSP under control of Modem/OS.


The Operating System (Modem/OS) is the real-time, multitasking DSP program that allows concurrent processing of virtual hardware tasks. Modem/OS schedule the DSP tasks to maximize concurrency.


Device drivers are programs that enable the application programs running on the PC to communicate with a specific peripheral device; for example, MIDI audio devices, wave audio devices, fax modem, data modem, telephone answering machine, or a CD-ROM drive.


The following terms are trademarks of IBM:

Operating System/2 	OS/2

IBM 	PC


personal computer (PC)


The manager is PC-based software that manages DSP resources and provides a hardware-independent interface layer between the device drivers and the underlying hardware.


DSP resources refer to the system resources available for use by the DSP and include DSP register space, memory (instruction store and data store), bandwidth on the ISA bus, and the number of MIPS that can be processed.


Millions of instructions per second (MIPS) are one characteristic of a DSP used to measure performance.


The Media Control Interface (MCI) is a Microsoft** Windows standard interface used for controlling internal and external media devices.


Musical instruments digital interface (MIDI) is a standard for the communication of musical control information from MIDI devices.


Waveform audio refers to a stream of digitized audio samples produced by an audio source.  It is synonymous with digital audio.


pulse code modulated (PCM)


telephone answering machine (TAM)


Contention refers to a situation in which two or more device drivers are trying to load and use DSP resources at the same time.  Without dynamic resource allocation, contention results in an error situation in which one or more of the device drivers cannot load.  This would return an error to the application that requested the functions provided by the device drivers.


Level of service refers to the quality of the function provided by the device driver. For example, the modem device driver can operate at 3 levels of services which correspond to modem transfer rates of 2400 bps, 14 400 bps, and 28 000 bps.


The CCITT standards body is now known as ITU-T.


MNP is a registered trademark of Microcom, Inc.


Hayes is a trademark of the Hayes Microcomputer Products, Inc.


The following terms are trademarks of their respective companies in the United States or other countries:

This term...  	Is a trademark of...

Sound Blaster 	Creative Labs

Microsoft 	Microsoft Corporation

Hayes 	Hayes Microcomputer Products, Inc.

Microcom Network Protocol 	Microcom, Inc.

MNP 	Microcom, Inc.

Compuserve 	Compuserve, Inc. and H and R Block, Inc.

America Online 	America Online, Inc.

Prodigy 	Prodigy Services Company

ReelMagic 	Sigma Designs


The following terms are trademarks of their respective companies in the United States or other countries:

WinFax Pro 	Delrina Technology Inc.

ProComm Plus 	Datastorm Technologies Inc.

Sprint 	Sprint Communications Company

MCI 	Microwave Communications Inc.

AT&T 	American Telephone and Telegraph Co.

GTE 	General Telephone Company


Concurrency refers to the number of applications that use the DSP that can run at the same time.


Direct Memory Access (DMA) is a technique used to transfer data directly between memory and hardware devices.  DMA transfers occur without the CPU acting as an intermediary and are preferred when using high-speed applications.


Interrupt Request (IRQ) is a software code sent to the CPU that controls programming activity or system resources.


Central Processing Unit (CPU) is the part of the computer that includes circuits that control the interpretation and execution of instructions.


Power on reset (POR) requires that you shut down the operating system and then turn off the system power. Then turn the system power on and restart the system.


Error Corrected Link.


Motion Picture Experts' Group