Multitech 5634 Series User manual

AT Commands
S-Registers
Result Codes
for the
5634 Modem Series
MT5634IND
MT5634ZBA Series
MT5634ZBA-USB
MT5634ZBA-DID
MT5634ZLX Series
MT5634ZPX-ISA
MT5634ZPX-PCI Series
ISI5634PCI Series
A Reference Guide

Copyright and Technical Support
Multi-Tech Systems, Inc. PN (S000272E) 2
AT Commands Reference Guide
Products: MT5634IND, MT5634ZBA Series including USB and DID, MT5634ZPX-PCI Series, MT5634ZPX-ISA,
MT5634ZLX Series, ISI5634PCI.
PN S000272E, Version E
Copyright
This publication may not be reproduced, in whole or in part, without prior expressed written permission from Multi-
Tech Systems, Inc. All rights reserved. Copyright © 2002-5, by Multi-Tech Systems, Inc.
Multi-Tech Systems, Inc. makes no representations or warranties with respect to the contents hereof and specifically
disclaims any implied warranties of merchantability or fitness for any particular purpose. Furthermore, Multi-Tech
Systems, Inc. reserves the right to revise this publication and to make changes from time to time in the content hereof
without obligation of Multi-Tech Systems, Inc. to notify any person or organization of such revisions or changes.
Revisions
Revision Level Date Description
A 10/30/02 Initial release.
B 02/24/03 Change +PIG=0 to enable PCM upstream with default 1.
Add #CBS4. Add +VRID.
C10/01/03 The guide is now applicable to the ISI5634PCI.
D 11/17/03 This guide is now applicable to the MT5634ZPX-ISA. Explained the default for
the S-Register S0: the default for internal modems is 0 while the default external
modems is 1.
E 01/04/05 Removed \X command. Added &L for the MT5634IND. Added Index cross-
references. Changed font.
Trademarks
MultiModem and the Multi-Tech logo are Registered Trademarks of Multi-Tech Systems, Inc.
World Headquarters
Multi-Tech Systems, Inc.
2205 Woodale Drive
Mounds View, Minnesota 55112
Phone: [phone] or 800-328-9717
Fax: [phone]
Technical Support
Country By Email By Phone
France: [email protected] (33) 1-64 61 09 81
India: [e-mail] 91 (124) 6340778
U.K.: [e-mail] (44) 118 959 7774
U.S. and Canada: [e-mail] [phone]
Rest of the World: [e-mail] [phone]
Internet Address: http://www.multitech.com

Contents
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 3
Contents
Chapter 1 - AT Commands............................................................................................................................................5
Introduction ..............................................................................................................................................................5
List of General Commands .....................................................................................................................................6
List of V.92 Commands ...........................................................................................................................................7
List of Caller ID Commands ....................................................................................................................................7
List of Callback Commands ....................................................................................................................................7
List of Escape Commands ......................................................................................................................................8
List of DID Commands.............................................................................................................................................8
AT Commands Detail ...............................................................................................................................................9
Command: AT Attention Code ..........................................................................................................................9
Command: A Answer........................................................................................................................................9
Command: A/ Repeat Last Command ..............................................................................................................9
Command: Bn Communication Standard Setting .............................................................................................9
Command: DsDial............................................................................................................................................9
Command: %M Enable Dialing Message........................................................................................................10
Command: DS=n Dial Stored Telephone Number ..........................................................................................10
Command: En Echo Command ......................................................................................................................10
Command: FnEcho Online Data Characters..................................................................................................10
Command: HnDisconnect (Hang Up).............................................................................................................10
Command: InInformation Request .................................................................................................................10
Command: LnNot Applicable .........................................................................................................................10
Command: MnMonitor Speaker Mode ...........................................................................................................10
Command: NnModulation Handshake ...........................................................................................................11
Command: OnReturn to Online Data Mode ...................................................................................................11
Command: P Set Pulse Dial Default ...............................................................................................................11
Command: QnResult Codes Enable/Disable .................................................................................................11
Command: Sr=n Set Register Value...............................................................................................................11
Command: Sr? Read Register Value..............................................................................................................11
Command: T Set Tone Dial Default ................................................................................................................11
Command: VnResult Code Format................................................................................................................11
Command: WnResult Code Options..............................................................................................................11
Command: XnResult Code Selection.............................................................................................................12
Command: Zn Modem Reset.........................................................................................................................12
Command: &CnData Carrier Detect (DCD) Control.......................................................................................12
Command: &DnData Terminal Ready (DTR) Control ....................................................................................12
Command: &EnXON/XOFF Pacing Control...................................................................................................12
Command: &FnLoad Factory Settings ...........................................................................................................12
Command: &GnV.22bis Guard Tone Control.................................................................................................12
Command: &KnFlow Control Selection..........................................................................................................13
Command: &Ln Leased-Line Operation..........................................................................................................13
Command: &QnAsynchronous Communications Mode.................................................................................13
Command: &SnData Set Ready (DSR) Control.............................................................................................13
Command: &TnV.54 Test Commands ...........................................................................................................13
Command: &V Display Current Settings .........................................................................................................13
Command: &WnStore Current Configuration.................................................................................................13
Command: &Zn=x Storing a Dialing Command ..............................................................................................14
Command: \AnSelect Maximum MNP Block Size..........................................................................................14
Command: \BnTransmit Break.......................................................................................................................14
Command: \KnBreak Control .........................................................................................................................14
Command: \NnError Correction Mode Selection............................................................................................14
Command: \QnFlow Control Selection...........................................................................................................15
Command: \TnInactivity Timer .......................................................................................................................15
Command: \VnProtocol Result Code .............................................................................................................15
Command: -CnData Calling Tone..................................................................................................................15
Command: %A Adaptive Answer Result Code Enable ...................................................................................15
Command: %B View Numbers in Blacklist......................................................................................................15

Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 4
Command: %CnData Compression Control ..................................................................................................15
Command: %DCnAT Command Control .......................................................................................................15
Command: %DTnSet the Command Mode Time...........................................................................................16
Command: %EnFallback and Fall Forward Control .......................................................................................16
Command: %HnDirect Connect Enable.........................................................................................................16
Command: %RnCisco Configuration .............................................................................................................16
Command: %SnCommand Speed Response................................................................................................16
Command: $DnDTR Dialing ..........................................................................................................................16
Command: $EBnAsynchronous Word Length ...............................................................................................16
Command: $FC Quick Connect ......................................................................................................................16
Command: $LB Long Break............................................................................................................................16
Command: $MBn Modem Baud Rate .............................................................................................................17
Command: $RP Response Priority .................................................................................................................17
Command: $SBnSerial Port Baud Rate .........................................................................................................17
V.92 Commands .....................................................................................................................................................18
Command: +PCW=n Call Waiting Enable .....................................................................................................18
Command: +PIG=n PCM Upstream Enable ..................................................................................................18
Command: +PMH=n Modem on Hold Enable ...............................................................................................18
Command: +PMHF V.92 Modem Hook Flash ...............................................................................................18
Command: +PMHR=n Modem on Hold Initiate ................................................................................................18
Command: +PMHT=n Modem on Hold Timer ...............................................................................................19
Command: +PQC=n Quick Connect Control .................................................................................................19
Command: +DCS=x,y Select V.44 Data Compression................................................................................19
Command: +DR=n V.44 Data Compression Reporting .................................................................................19
Command: +DS44=n V.44 Data Compression.............................................................................................20
Command: +MS= Modulation Selection ........................................................................................................21
Caller ID Commands ..............................................................................................................................................22
Command: +VCID=n Caller ID Selection.......................................................................................................22
Command: +VDR=x,y Distinctive Ring Report .............................................................................................22
Command: +VRID Caller ID Query ................................................................................................................22
Callback Security Commands...............................................................................................................................23
Command: #CBAn Callback Attempts...........................................................................................................23
Command: #CBDn Callback Delay ...............................................................................................................23
Command: #CBF? Callback Failed Attempts Display ...................................................................................23
Command: #CBFR Callback Failed Attempts Reset .....................................................................................23
Command: #CBIn Local Callback Inactivity Timer.........................................................................................23
Command: #CBNy=x Store Callback Password............................................................................................23
Command: #CBPn Callback Parity................................................................................................................23
Command: #CBRy Callback Security Reset..................................................................................................23
Command: #CBSn Callback Enable/Disable.................................................................................................24
Command: #Pn Set 11-bit Parity ...................................................................................................................24
Command: #Sx Enter Setup Password..........................................................................................................24
Command: #S=x Store Setup Password .......................................................................................................24
Escape Sequence Commands ..............................................................................................................................24
Command: +++AT<CR> Escape Sequence..................................................................................................24
Command: %%%ATMTSMODEM<CR> Remote Configuration Escape Sequence...................................24
DID Commands ......................................................................................................................................................25
Command: *DS Start Protocol ........................................................................................................................25
Command: *DT Wait for Digit Time-Out Time.................................................................................................25
Command: *DD Digit Format .........................................................................................................................25
Command: *DN Number of DID Digits Expected..........................................................................................25
Command: *DW Busy-Out Timer at End of Call ............................................................................................26
About the Busy-Out Features and Functions .......................................................................................................26
Command: *DF Format for Reporting Incoming DID Number.........................................................................26
Chapter 2 - S-Registers ...............................................................................................................................................27
Chapter 3 - Result Codes ............................................................................................................................................30
Index .............................................................................................................................................................................31

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 5
Chapter 1 - AT Commands
Introduction
The AT commands are used to control the operation of your modem. They are called AT commands because the
characters AT must precede each command to get the ATtention of the modem.
AT commands can be issued only when the modem is in command mode or online command mode. The modem
is in command mode whenever it is not connected to another modem. The modem is in data mode whenever it is
connected to another modem and ready to exchange data. Online command mode is a temporary state in which
you can issue commands to the modem while connected to another modem. To put the modem into online
command mode from data mode, you must issue an escape sequence (+++) followed immediately by the AT
characters and the command, e.g., +++ to hang up the modem. To return to data mode from online command
mode, you must issue the command ATO.
To send AT commands to the modem you must use a communications program, such as the HyperTerminal
applet in Windows 98/95 and NT 4.0, or some other available terminal program. You can issue commands to the
modem either directly, by typing them in the terminal window of the communications program, or indirectly, by
configuring the operating system or communications program to send the commands automatically. Fortunately,
communications programs make daily operation of modems effortless by hiding the commands from the user.
Most users, therefore, need to use AT commands only when reconfiguring the modem, e.g., to turn autoanswer
on or off.
The format for entering an AT command is ATXn, where Xis the command and nis the specific value for the
command, sometimes called the command parameter. The value is always a number. If the value is zero, you
can omit it from the command; thus, AT&W is equivalent to AT&W0. Most commands have a default value,
which is the value that is set at the factory.
You must press ENTER (depending on the terminal program it could be some other key) to send the command
to the modem. Any time the modem receives a command, it sends a response known as a result code. The
most common result codes are OK, ERROR, and the CONNECT messages that the modem sends to the
computer when it is connecting to another modem.
You can issue several commands in one line, in what is called a command string. The command string begins
with AT and ends when you press ENTER. Spaces to separate the commands are optional; the command
interpreter ignores them. The most familiar command string is the initialization string, which is used to
configure the modem when it is turned on or reset, or when your communications software calls another modem.

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 6
List of General Commands
Command Description
AT Attention Code
A Answer
A/ Repeat Last Command
B Communication Standard Setting – Bell or CCITT
D Dial
%M Enable Dialing Message
DS=nDial Stored Telephone Number
E Echo Command
F Echo Online Data Characters
H Disconnect (Hang Up)
I Information Request
L Not Applicable
M Monitor Speaker Mode
N Modulation Handshake
O Return to Online Data Mode
P Set Pulse Dial Default
Q Result Codes Enable/Disable
Sr=n Set Register Value
Sr? Read Register Value
T Set Tone Dial Default
V Result Code Format
W Result Code Options
X Result Code Selection
Z Modem Reset
&C Data Carrier Detect (DCD) Control
&D Data Terminal Ready (DTR) Control
&E XON/OFF Pacing Control
&F Restore Factory Settings (Configuration)
&G Select Guard Tone Control
&K Flow Control Selection
&L Leased-Line Operation
&Q Asynchronous Communication Mode (same as \N Error Correction Mode)
&S Data Set Ready (DSR) Control
&T Loopback Tests
&V Display Current Settings (Configuration and Stored Profiles)
&W Store Current Settings (Configuration and Stored Profiles)
&Zn=x Store Dialing Command
\A Select Maximum MNP Block Size
\B Transmit Break to Remote
\K Break Control
\N Error Correction Mode Selection
\Q Flow Control Selection
\T Inactivity Timer
\V Protocol Result Code
-C Data Calling Tone
%A Adaptive Answer Result Code Enable
%B View Numbers in Blacklist
%C Data Compression Enable/Disable
%DC AT Command Control
%DT “AT” Command Timer
%E Fallback and Fall Forward Control
%H Direct Connect Enable
%R Cisco Configuration
%S Response Speed
$D DTR Dialing
$EB Asynchronous Word Length
$LB Long Break
$RP Response Priority
$SB Serial Port Baud Rate

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 7
List of V.92 Commands
Command Description
+PCW=nCall Waiting Enable
+PIG=nPCM Upstream Enable
+PMH=nModem-on-Hold Enable
+PMHF V.92 Modem Hook Flash
+PMHR=nModem-on-Hold Initiate
+PMHTR=nModem-on-Hold Timer
+PQC=nQuick Connect Control
+DCS=x,y Select V.44 Data Compression
+DR=nV.44 Data Compression Reporting
+DS44=nV.44 Data Compression
+MS Modulation Selection
$FC Quick Connect
List of Caller ID Commands
Command Description
+VCID Caller ID Enable/Disable
+VDR=x,y Distinctive Ring Report “ERROR”
+VRID Allows query of modem’s last call received
List of Callback Commands
These commands are used with modems that support Callback Security
Command Description
#CBA Callback Attempts
#CBD Callback Delay
#CBF? Callback Failed Attempts Display
#CBFR Callback Failed Attempts Reset
#CBI Local Callback Inactivity Timer
#CBNy=x Store Callback Password
#CBP Callback Parity
#CBR Callback Security Reset
#CBS Callback Enable/Disable
#P Set 11-bit Parity
#SxEnter Setup Password
#S=xStore Setup Password

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 8
List of Escape Commands
Command Description
+++AT Escape Sequence
%%%ATMTSMODEM Remote Configuration Escape Sequence
List of DID Commands
Command Description
*DD Digit Format
*DF Format for Reporting Incoming DID Number
*DS Start Protocol
*DT Wait for Digit Time-Out Time
*DW Busy Out After Call Completion
*DN Number of DID Digits
*DW Busy Out After Call Completion
*DN Number of DID Digits

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 9
AT Commands Detail
Command: AT Attention Code
Values: n/a
Description: The attention code precedes all command lines except A/ and escape sequences.
Command: A Answer
Values: n/a
Description: Answer an incoming call before the final ring.
Command: A/ Repeat Last Command
Values: n/a
Description: Repeat the last command string. Do not precede this command with AT. Do not press ENTER
to execute.
Command: Bn Communication Standard Setting
Values: n= 0-3, 15, 16
Default: 1 and 16
Description: B0 Select ITU-T V.22 mode when modem is at 1200 bps
B1 Select Bell 212A when modem is 1200 bps.
B2 Deselect V.23 reverse channel (same as B3).
B3 Deselect V.23 reverse channel (same as B2).
B15 Select V.21 when modem is at 300 bps.
B16 Select Bell 103 when modem is at 300 bps.
Command: DsDial
Values: s= dial string (phone number and dial modifiers)
Default: none
Description: Dial telephone number s, where smay be up to 40 characters long and include these
characters: 0-9, *, #, A, B, C, D
Can also include these Dial String Modifiers: L, P, T, W, S, comma (,), semicolon (;), !, @, ^,
and $.
Dial String Characters and Modifiers
0-9 DTMF digits 0 to 9.
*The 'star' digit (tone dialing only).
#The 'gate' digit (tone dialing only).
A-D Some countries may prohibit sending of these digits during dialing (tone dialing
only)
LRedial last number. (Must be placed immediately after ATD.)
PSelects pulse dialing until a Tis encountered. Affects current and subsequent
dialing. Some countries prevent changing dialing modes after the first digit is
dialed.
TSelects tone dialing until a Pis encountered. Affects current and subsequent
dialing. Some countries prevent changing dialing modes after the first digit is
dialed.
WWait for a new dial tone before continuing to dial. (X2, X4, X5, X6, or X7 must be
selected).
S=n Dial the number stored in the directory (n = 0 to 3). (See &Z.)
,Pause during dialing for set set in in register S8.
;Return to command mode after dialing. Place at the end of dial string.
!Hook Flash. Causes the modem to go on-hook for a time defined by the value of
S29, then off-hook again. Country requirements may limit the time imposed.
@Wait for quiet answer (silence). Causes the modem to wait for a ring back, then 5
seconds of silence before processing the next part of the command. If silence is
not detected, the modem returns a NO ANSWER code.
^Toggles the calling tone between enable/disable. Applicable to current dial
attempt only.
$ Detect AT&T call card “bong” tone. The character should follow the phone
number and precede the user’s call card number:
ATDT1028806127853500$123456789

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 10
Ignored Characters
( ) Ignored: may be used to format the dial string.
-Ignored: may be used to format the dial string.
<space> Ignored: may be used to format the dial string.
<i> Invalid character: will be ignored.
Command: %M Enable Dialing Message
Values: 0, 1
Default: 0
Description: Enables dialing message. It will display when the ATDL=n command is used and dialing
from memory or DTR dialing.
0 = Disabled - turns dialing message off
1 = Enabled - turns dialing message on
Command: DS=n Dial Stored Telephone Number
Values: n= 0, 1, 2
Default: none
Description: Dials a number previously stored in the directory by the &Zn=x command. Ex: ATDS=2.
Command: En Echo Command
Values: n= 0 or 1
Default: 1
Description: E0 Disables echo command.
E1 Enables echo command.
Command: FnEcho Online Data Characters
Values: n = 0, 1
Default: 1
Description: F0 Enables online data character echo. (Not supported.)
F1 Disables online data character echo (included for backward compatibility).
Command: HnDisconnect (Hang Up)
Values: n= 0 or 1
Default: 0
Description: H0 The modem goes on-hook (hangs up).
H1 The modem goes off-hook (makes the phone line busy).
Command: InInformation Request
Values: n= 0–5, 9, 11
Default: None
Description: I0 Displays default speed and controller firmware version.
I1 Calculates and displays ROM checksum (e.g., B399).
I2 Checks ROM and verifies the checksum, displaying OK or ERROR.
I3 Displays default speed and controller firmware version.
I4 Displays firmware version for data pump (e.g., 17)..
I5 Displays the board ID: software version, hardware version, and the country ID in
hexidecimal format (e.g., s0503a01V, 0,34).
I7 Displays release information and V.92 capabilities.
I9 Displays the country code in decimal format (e.g., 52).
I11 Displays diagnostic information for the last modem connection, such as DSP and
firmware version, link type, line speed, serial speed, type of error correction/data
compression, number of past retrains, etc.
Command: LnNot Applicable
Command: MnMonitor Speaker Mode
Values: n = 0, 1, 2, or 3
Default: 1
Description: M0 Speaker always off.
M1 Speaker on until carrier signal detected.
M2 Speaker always on when modem is off-hook.
M3 Speaker on until carrier is detected, except while dialing.

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 11
Command: NnModulation Handshake
Values: n = 0 or 1
Default: 1
Description: N0 Modem performs handshake only at communication standard specified by S37 and the
Bcommand.
N1 Modem begins handshake at communication standard specified by S37 and the B
command. During handshake, fallback to a lower speed can occur.
Command: OnReturn to Online Data Mode
Values: 0, 1, 3
Default: None
Description: O0 Exits online command and returns to data mode (see +++AT escape sequence).
O1 Issues a retrain and returns to online data mode.
O3 Issues a rate renegotiation and returns to data mode.
Command: P Set Pulse Dial Default
Values: P, T
Default: T
Description: Configures the modem for pulse (non-touch-tone) dialing. Dialed digits are pulsed until a T
command or dial modifier is received.
Command: QnResult Codes Enable/Disable
Values: n= 0 or 1
Default: 0
Description: Q0 Enables result codes.
Q1 Disables result codes.
Q2 Dumb Answer Mode (also known as No Response Answer). Q2 sets the answer
mode to be handled without responses and echo turned off; however, the originate
mode remains intelligent.
Command: Sr=n Set Register Value
Values: r= S-Register number; n varies
Default: None
Description: Sets the value of the register Srto the value of n, where nis entered in decimal format:
Example: S0=1.
Command: Sr? Read Register Value
Values: r= S-Register number
Default: None
Description: Reads the value of the register Srand displays it in 3-digit decimal form. Example: S2?
gives the response 043.
Command: T Set Tone Dial Default
Values: P, T
Default: T
Description: Configures the modem DTMF (touch-tone) dialing. Dialed digits are tone dialed until a P
command or dial modifier is received.
Command: VnResult Code Format
Values: n= 0 or 1
Default: 1
Description: V0 Displays result codes as digits (short form or terse).
V1 Displays result codes as words (long-form or verbose).
Command: WnResult Code Options
Values: n = 0, 1, 2
Default: 2
Description: W0 CONNECT result code reports serial port speed, disables protocol result codes.
W1 CONNECT result code reports serial port speed, enables protocol result codes.
W2 CONNECT result code reports line speed, enables protocol result codes.

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 12
Command: XnResult Code Selection
Values: n = 0–7
Default: 4
Description: X0 Basic result codes (e.g., CONNECT); does not look for dial tone or busy signal.
X1 Extended result codes (e.g., CONNECT 46000 V42bis); does not look for dial tone or
busy signal.
X2 Extended result codes with NO DIALTONE; does not look for busy signal.
X3 Extended result codes with BUSY; does not look for dial tone.
X4 Extended result codes with NO DIALTONE and BUSY.
X5 Extended result codes with NO DIALTONE and BUSY.
X6 Extended result codes with NO DIALTONE and BUSY.
X7 Basic result codes with NO DIALTONE and BUSY.
Command: Zn Modem Reset
Values: n = 0 or 1
Default: None
Description: Z0 Resets modem to profile saved by the last &W command.
Z1 Same as Z0.
Command: &CnData Carrier Detect (DCD) Control
Values: n = 0, 1, or 2
Default: 1
Description: &C0 Forces the DCD circuit to be always high.
&C1 DCD goes high when the remote modem’s carrier signal is detected, and goes low
when the carrier signal is not detected.
&C2 DCD drops on disconnect for time set by S18, then goes high again (for some PBX
phone systems).
Command: &DnData Terminal Ready (DTR) Control
Values: n = 0, 1, 2, or 3
Default: 2
Description: &D0 Modem ignores the true status of the DTR signal and responds as if it is always on.
&D1 If DTR drops while in online data mode, the modem enters command mode, issues
an OK, and remains connected.
&D2 If DTR drops while in online data mode, the modem hangs up. If the signal is not
present, the modem will not answer or dial.
&D3 If DTR drops, the modem hangs up and resets as if an ATZ command were issued.
Command: &EnXON/XOFF Pacing Control
Values: n = 12 or 13
Default: 12
Description: &E12 Disables XON/XOFF pacing.
&E13 Enables XON/XOFF pacing. (&K4 must also be set.)
Note: &E13 has no effect if hardware control (&K3) is selected.
Command: &FnLoad Factory Settings
Values: n = 0
Default: None
Description: &F0 Loads factory settings as active configuration.
Note: See also the Z command.
Command: &GnV.22bis Guard Tone Control
Values: n = 0, 1, or 2
Default: 0
Description: &G0 Disables guard tone.
&G1 Sets guard tone to 550 Hz.
&G2 Sets guard tone to 1800 Hz.
Note: The &G command is not used in North America.

Chapter 1 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (PN S000272E) 13
Command: &KnFlow Control Selection
Values: n = 0, 3, or 4
Defaults: 3
Description: &K0 Disables flow control.
&K3 Enables CTS/RTS hardware flow control.
&K4 Enables XON/XOFF software flow control.
Command: &Ln Leased-Line Operation
Note: This command applies to the MT5634IND (Industrial Temperature Modem)
Values: n= 0, 1, or 2
Defaults: 0
Description: &L0 The modem is set for standard dial-up operation.
&L1 The modem is set for leased line operation in originate mode.
&L2 The modem is set for leased line operation in answer mode.
Note: For &L1 and &L2, there is a 30-second window between power up and the starting of
the leased line handshake. During this time, you can turn off the command, if desired.
Command: &QnAsynchronous Communications Mode
Values: n = 0, 5, 6, 8, or 9
Default: 5
Description: &Q0 Asynchronous with data buffering. Same as \N0.
&Q5 Error control with data buffering. Same as \N3.
&Q6 Asynchronous with data buffering. Same as \N0.
&Q8 MNP error control mode. If MNP error control is not established, the modem falls
back according to the setting in S36.
&Q9 V.42 or MNP error control mode. If neither error control is established, the modem
falls back according to the setting in S36.
Command: &SnData Set Ready (DSR) Control
Values: n = 0 or 1
Default: 0
Description: &S0 DSR is always high (on).
&S1 DSR goes high only during a connection.
Command: &TnV.54 Test Commands
Values: n = 0, 1, 3 or 6
Default: None
Description: &T0 Abort. Stops any test in progress.
&T1 Initiates local analog loopback test.
&T3 Initiates local digital loopback test.
&T6 Initiates remote digital loopback test.
Note: To stop a test, use the escape sequence (+++AT) before typing &T0.
Command: &V Display Current Settings
Values: n/a
Description: Displays the active modem settings, including the callback security settings if callback
security is enabled. If the setup password has been entered, it also displays the callback
security passwords.
Command: &WnStore Current Configuration
Values: n = 0, 1
Default: 1
Description: &W0 Stores current modem settings in nonvolatile memory and causes them to be loaded
in place of the factory defaults at power-on or following the ATZ command. See also
the &F command.
&W1 Clears user default settings from nonvolatile memory and causes the factory defaults
to be loaded at power-on or following the ATZ command.

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Command: &Zn=x Storing a Dialing Command
Values: n = 0–3. Callback security disabled. 0, 1 used by MultiModemZPX/ZLI.
0, 1, 2 used by MultiModemZBA.
0–29. Callback security enabled.
x = Stored telephone number
Default: None
Description: Stores dialing command x in memory. Dial the stored number using the command ATDS=n.
See also the #CBSn command.
Command: \AnSelect Maximum MNP Block Size
Values: n = 0, 1, 2, or 3
Default: 3
Description: \A0 64-character maximum.
\A1 128-character maximum.
\A2 192-character maximum.
\A3 256-character maximum.
Command: \BnTransmit Break
Values: n = 0–9 in 100 ms units
Default: 3
Description: In non-error-correction mode only, sends a break signal of the specified length to a remote
modem. Works in conjunction with the \K command.
Command: \KnBreak Control
Values: n = 0–5
Default: 5
Description: Controls the modem’s response to a break received from the computer, the remote modem,
or the \B commnd. The response is different for each.
Data mode. Modem receives the break from the computer:
\K0 Enters online command mode, no break sent to the remote modem.
\K1 Clears data buffers and send break to the remote modem.
\K2 Same as \K0.
\K3 Sends break immediately to the remote modem .
\K4 Same as \K0.
\K5 Sends break to the remote modem in sequence with the transmitted data.
Data mode. Modem receives the break from the remote modem:
\K0 Clears data buffers and sends break to the computer.
\K1 Same as \K0.
\K2 Sends break immediately to the computer.
\K3 Same as \K2.
\K4 Sends break to the computer in sequence with the received data.
\K5 Same as \K4.
Online command mode. Modem receives a \Bn command from the computer:
\K0 Clears data buffers and sends break to the remote modem.
\K1 Same as \K0.
\K2 Sends break immediately to the remote modem.
\K3 Same as \K2.
\K4 Sends break to the remote modem in sequence with the transmitted data.
\K5 Same as \K4.
Command: \NnError Correction Mode Selection
Values: n = 0–5, or 7
Default: 3
Description: \N0 Non-error correction mode with data buffering (same as &Q6).
\N1 Direct mode.
\N2 MNP reliable mode. If modem cannot make MNP connection, it disconnects.
\N3 V.42/MNP auto-reliable mode. The modem attempts first to connect in V.42 error
correction mode, then in MNP mode, and finally in non-error-correction (buffer)
mode with continued operation.
\N4 V.42 reliable mode.If the modem cannot make a V.42 connection, it disconnects.
\N5 V.42, MNP, or non-error correction (same as \N3).
\N7 V.42, MNP, or non-error correction (same as \N3).

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Command: \QnFlow Control Selection
Values: n = 0, 1, or 3
Default: 3
Description: \Q0 Disables flow control (same as &K0).
\Q1 XON/XOFF software flow control (same as &K4).
\Q2 CTS-only flow control. Not supported.
\Q3 RTS/CTS hardware flow control (same as &K3).
Command: \TnInactivity Timer
Values: n = 0, 1–255
Default: 0
Description: \Tn Sets the time (in minutes) that the modem waits after the last character is sent or
received before it disconnects. A value of zero disables the timer. Applies only in
buffer mode.
Note: You can also set the inactivity timer by changing the value of S30.
Command: \VnProtocol Result Code
Values: n = 0, 1, or 2
Default: 1
Description: \V0 Disables the appending of the protocol result code to the DCE speed.
\V1 Enables the appending of the protocol result code to the DCE speed.
\V2 Same as \V1.
Command: -CnData Calling Tone
Values: n = 0 or 1
Defaults: 0
Description: -C0 Disables V.25 data calling tone to deny remote data/fax/voice discrimination.
-C1 Enables V.25 data calling tone to allow remote data/fax/voice discrimination.
Command: %A Adaptive Answer Result Code Enable
Values: n = 0 or 1
Default: 0
Description: The %A command controls whether the DATA and FAX result codes will be sent by the
modem. The modem must be in fax mode for this command to work. Also, the modem must
be set to +FAA=1, which enables the modem to distinguish between a fax and a data call.
When these commands are enabled, the modem sends DATA to the computer when it
detects data tones, and FAX when it detects fax tones. These strings are used by some
servers to select the appropriate communication program.
%A0 Disables adaptive answer result codes.
%A1 Enables adaptive answer result codes.
Note: For descriptions of the +FAA= and other fax commands, see the Multi-Tech Fax Class
2.1 Developer’s Guide.
Command: %B View Numbers in Blacklist
Values: n/a
Description: If blacklisting is in effect, AT%B displays the numbers for which the last call attempted in the
previous two hours failed. In countries that do not require blacklisting, the ERROR result
code appears.
Command: %CnData Compression Control
Values: n = 0 or 1
Default: 1
Description: %C0 Disable sV.42bis/MNP 5 data compression.
%C1 Enables V.42bis/MNP 5 data compression.
Command: %DCnAT Command Control
Values: n = 0 or 1
Default: 0
Description: %DC0 The modem responds to AT commands.
%DC1 The modem ignores AT commands.
Note: The modem will respond to AT%DC for 10 seconds after it is turned on.

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Command: %DTnSet Command Mode Time
Values: 0-255 in 1 second increments
Default: 0
Description: Sets the length of time that the command mode will be disabled when set for %DC1 (the
modem ignores AT commands).
Command: %EnFallback and Fall Forward Control
Values: n = 0, 1, or 2
Default: 2
Description: %E0 Disables fallback and fall-forward.
%E1 Enables fallback, disables fall-forward.
%E2 Enables fallback and fall-forward.
Command: %HnDirect Connect Enable
Values: n = 0, 1
Default: 0
Description: %H0 Sets callback security to normal operation.
%H1 All callback security calls will be direct connect regardless of whether the password
or phone number has the -character.
Command: %RnCisco Configuration
Values: n = 0, 1
Default: 0
Description: %R0 Disables Cisco configuration.
%R1 Sets E0, Q1, &D0, \N0, $SB9600, and %S1 for operation with a Cisco router.
Command: %SnCommand Speed Response
Values: n = 0, 1
Default: 0
Description: %S0 Sets modem to respond to AT commands at all normal speeds.
%S1 AT commands accepted at 115200 bps only. Other speeds are ignored.
Command: $DnDTR Dialing
Values: n = 0 or 1
Default: 0
Description: $D0 Disables DTR dialing.
$D1 Dials the number in memory location 0 when DTR goes high.
Command: $EBnAsynchronous Word Length
Values: n = 0 or 1
Default: 0
Description: $EB0 Enables 10-bit mode.
$EB1 Enables 11-bit mode.
Command: $FC Quick Connect
Values: n = 0, 1, or 2
Default: 1
Description: $FC0 - Sets quick connect at 1200 baud
$FC1 - No quick connect
$FC2 - Sets quick connect at 2400 baud
Command: $LB Long Break
Values: 0-255 in 10 ms increments
Default: 30 (300 ms break)
Description: Sets the length of a long break transmitted by the modem if set up by the modem.

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Command: $MBn Modem Baud Rate
Values: 75, 300, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 33600
Default: 33600
Description: Presets the transmission baud rate for originate operations (i.e., the speed of the modem’s
transmissions over the telephone lines when originating a call). With speed conversion,
transmission speed can be a different baud rate than the serial port speed.
When the modem receives a call from another modem, it automatically switches its phone
line transmission speed to match the calling mode. However, if the MultiModem originates a
call to another modem that is unable to connect at the MultiModem’s baud rate, it
automatically drops to the lower baud rate in an attempt to match that modem’s speed. For
example, if the MultiModem is set for 19200 baud and calls a modem with a top speed of
2400 baud, it drops to 2400 baud.
AT$MB75 = V.23
AT$MB300 = 300 bps
AT$MB1200 = 1200 bps
AT$MB2400 = 2400 bps
AT$MB4800 = 4800 bps
AT$MB9600 = 9600 bps
AT$MB14400 = 14400 bps
AT$MB19200 = 19200 bps
AT$MB28800 = 28800 bps
AT$MB33600 = 33600 bps
Command: $RP Response Priority
Values: n = 0, 1
Default: 1
Description: Configures whether an incoming ring or an AT command will have priority.
$RP0 - AT command will have priority
$RP1 - Incoming call (ring) will have priority
Command: $SBnSerial Port Baud Rate
Values: n = speed in bits per second
Default: 57600
Description: $SB300 Set serial port to 300 bps.
$SB1200 Set serial port to 1200 bps.
$SB2400 Set serial port to 2400 bps.
$SB4800 Set serial port to 4800 bps.
$SB9600 Set serial port to 9600 bps.
$SB19200 Set serial port to 19200 bps.
$SB38400 Set serial port to 38400 bps.
$SB57600 Set serial port to 57600 bps.
$SB115200 Set serial port to 115200 bps.
$SB230400 Set serial port to 230400 bps. (V.92 models only)

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V.92 Commands
Command: +PCW=n Call Waiting Enable
Values: n = 0, 1, or 2
Default: 0
Description: Controls the action to be taken upon detection of a call waiting tone in V.92 mode. Values
specified by this command are not modified when an AT&F command is issued.
+PCW=0 Toggles V.24 Circuit 125 and collects Caller ID if enabled by +VCID
+PCW=1 Hangs up
+PCW=2 Ignores V.92 call waiting
+PCW=? Displays the allowed values
+PCW? Displays the current value
Command: +PIG=n PCM Upstream Enable
Values: n = 0 or 1
Default: 1
Description: Controls the use of PCM upstream during V.92 operation. PCM upstream allows faster
upload speeds to a V.92 server.
+PIG=0 Enable PCM upstream
+PIG=1 Disable PCM upstream
+PIG=? Displays the allowed values
+PIG? Displays the current value
Command: +PMH=n Modem on Hold Enable
Values: n = 0 or 1
Default: 1
Description: Controls if modem on hold procedures are enabled during V.92 operation. Normally
controlled by a modem on hold program. Values specified by this command are not modified
when an AT&F command is issued.
+PMH=0Enables V.92 modem on hold
+PMH=1Disables V.92 modem on hold
+PMH=?Displays the allowed values
+PMH? Displays the current value
Command: +PMHF V.92 Modem Hook Flash
Values: n/a
Default: n/a
Description: Causes the DCE to go on-hook for a specified period of time, and then return off-hook for at
least a specified period of time. The specified period of time is normally one-half second, but
may be governed by national regulations. “ERROR” is returned if MOH is not enabled.
Command: +PMHR=n Modem on Hold Initiate
Values: n = 0–13
Default: 0
Description: +PMHR is an action command that causes the modem to initiate MOH with the central site
modem. It returns the following values to indicate negotiated values. Valid only if MOH is
enabled and the modem is off-hook or in data mode. Otherwise, ERROR will be returned.
+PMHR=0 Deny MOH request
+PMHR=1 Grant MOH request with 10 second timeout
+PMHR=2 Grant MOH request with 20 second timeout
+PMHR=3 Grant MOH request with 30 second timeout
+PMHR=4 Grant MOH request with 40 second timeout
+PMHR=5 Grant MOH request with 1 minute timeout
+PMHR=6 Grant MOH request with 2 minute timeout
+PMHR=7 Grant MOH request with 3 minute timeout
+PMHR=8 Grant MOH request with 4 minute timeout
+PMHR=9 Grant MOH request with 6 minute timeout
+PMHR=10 Grant MOH request with 8 minute timeout
+PMHR=11 Grant MOH request with 12 minute timeout
+PMHR=12 Grant MOH request with 16 minute timeout
+PMHR=13 Grant MOH request with indefinite timeout
+PMHR=? Displays the allowed values
+PMHR? Displays the current value

Chapter 1 – AT Commands
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Command: +PMHT=n Modem on Hold Timer
Values: n = 0–13
Default: 0
Description: Determines if the modem will accept a V.92 Modem on Hold request; sets the MoH timeout.
+PMHT=0 Deny MOH request
+PMHT=1 Grant MOH request with 10 second timeout
+PMHT=2 Grant MOH request with 20 second timeout
+PMHT=3 Grant MOH request with 30 second timeout
+PMHT=4 Grant MOH request with 40 second timeout
+PMHT=5 Grant MOH request with 1 minute timeout
+PMHT=6 Grant MOH request with 2 minute timeout
+PMHT=7 Grant MOH request with 3 minute timeout
+PMHT=8 Grant MOH request with 4 minute timeout
+PMHT=9 Grant MOH request with 6 minute timeout
+PMHT=10 Grant MOH request with 8 minute timeout
+PMHT=11 Grant MOH request with 12 minute timeout
+PMHT=12 Grant MOH request with 16 minute timeout
+PMHT=13 Grant MOH request with indefinite timeout
+PMHT=? Displays the allowed values
+PMHT? Displays the current value
Command: +PQC=n Quick Connect Control
Values: n = 0, 1, 2, or 3
Default: 3
Description: Controls the V.92 shortened Phase 1 and Phase 2 startup procedures (Quick Connect).
When line conditions are stable, quick connect results in shortened connect times; however,
significant fluctuation in line conditions from call to call can result in longer connect times, in
which case it may be advisable to disable quick connect.
+PQC=0 Enables Short Phase 1 and Short Phase 2 (Quick Connect)
+PQC=1 Enables Short Phase 1
+PQC=2 Enables Short Phase 2
+PQC=3 Disables Short Phase 1 and Short Phase 2
+PQC=? Displays the allowed values
+PQC? Displays the current value
Command: +DCS=x,y Select V.44 Data Compression
Values: x = 0 or 1 (V.42bis)
y = 0, 1, or 2 (V.44)
Default: 1, 2
Description: Selects V.42bis/V.44 data compression.
+DCS=0,0 V.42bis and V.44 data compression are both disabled.
+DCS=0,1 V.42bis is disabled; V.44 data compression is acceptable.
+DCS=0,2 V.42bis is disabled; V.44 only when connected to a V.92 server.
+DCS=1,0 V.42bis is acceptable; V.44 data compression is disabled.
+DCS=1,1 V.42bis is acceptable; V.44 data compression is acceptable.
+DCS=1,2 V.42bis is acceptable; V.44 only when connected to a V.92 server.
+DCS=? Displays the allowed values.
+DCS? Displays the current value.
Command: +DR=nV.44 Data Compression Reporting
Values: n = 0 or 1
Default: 0
Description: Enables or disables the V.44 data compression report. If the compression report is enabled,
the +DR:<type> intermediate result code reports the current DCE-DCE data compression
type. It is issued after the Error Control Report (+ER) and before the final result code (e.g.,
CONNECT). The intermediate result code descriptions are shown after the command -
descriptions.
+DR=0 Disables the V.44 compression report.
+DR=1 Enables the V.44 compression report.
+DR=? Displays the allowed values.
+DR? Displays the current value.
+DR: NONE Data compression not in use.
+DR: V42B V.42bis is in use in both directions.
+DR: V44 V.44 is in use in both directions.

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Command: +DS44=nV.44 Data Compression
Values: See description
Default: See description
Description: Controls the V.44 data compression function.
The command syntax is +DS44=[direction][,[0][,[0]
[,[max_codewords_tx][,[max_codewords_rx][,[max_string_tx]
[,[max_string_rx][,[max_history_tx][,[max_history_rx]]]]]]]]]<CR> Subparameters that are not
entered retain their current value. Commas separate optional subparameters, and must be
inserted to skip a subparameter. Example: +DS44=,,,2048,2048<CR> changes the
maximum number of code words in both directions, and keeps all other settings at their
current values.
+DS44=? Reports supported options in the format (list of supported direction values), (0),
(0), (list of supported max_codewords_tx values), (list of supported max_codewords_rx
values), (list of supported max_string_tx values), (list of supported max_string_rx values),
(list of supported max_history_tx values), (list of supported max_history_rx values).
Example: +DS44: (3, 0), (0), (0), (256-2048), (256-2048), (31-255), (31-255), (512-11008),
(512-11008).
+DS44? Reports current options in the following format:
direction, 0, 0, max_codewords_tx, max_codewords_rx, max_string_tx, max_string_rx,
max_history_tx, max_history_rx.
Example: +DS44: 3, 0, 0, 1024, 1024, 255, 255, 5120, 4096.
Subparameters
direction Specifies the DTE direction of the data compression.
0 No compression.
3 Compression in both directions (default).
max_codewords_tx Specifies the maximum number of code words to be negotiated in the
transmit direction.
1024 Default.
256–2048 Maximum number of code words in transmit direction.
max_codewords_rx Specifies the maximum number of code words to be negotiated in the
receive direction.
1024 Default.
256–2048 Maximum number of code words in receive direction.
max_string_tx Specifies the maximum string length to be negotiated in the transmit
direction.
255 Default.
31–255 Maximum string length in transmit direction.
max_string_rx Specifies the maximum string length to be negotiated in the
receivedirection.
255 Default.
31–255 Maximum string length in receivedirection.
max_history_tx Specifies the maximum length of the history buffer to be negotiated in the
transmit direction.
5120 Default.
512–11008 History buffer size in transmit direction.
max_history_rx Specifies the maximum length of the history buffer to be negotiated in the
receive direction.
4096 Default.
512–11008 History buffer size in receive direction