Table Of Contents
AT Command Set and Register Summary for V.34, 56K, and V.90 12-Port Modules
Entering AT Commands
Alphabetic Command Set
A (Answer)
A/ (Repeat Last Command)
AT (Attention)
Bn (ITU/Bell Mode)
D {dial string} (Dial)
Dial Modifiers
En (Command Echo)
H (Hang Up)
In (Identification)
On (Enter Connect State)
Qn (Quiet)
Sn? (Read Configuration Register)
T (Tone Dial)
Vn (Result Code Form)
Wn (Connection Speed Reporting)
Xn (Extended Result Codes)
Yn (Long Space Disconnect)
Z (Reset)
Caret Command Set
^H (Host Port Upgrade)
^V (Display Bootstrap Revision)
Dollar Command Set
$Bn (Serial Port Bps Rate)
$D (Power-Up Diagnostics)
Percent Command Set
%An (Autoreliable Fallback Character)
%Bn (Modem Port Bps Rate)
%Cn (Compression Control)
%Dn (Disconnect Buffer Delay)
%En (Autoretrain)
%Fn (V.23 Mode)
%Gn (Independent Serial Port and Modem Port Speed)
%Ln (Speed Matching)
%M (Modulation)
%Mn (Modulation Selection)
%Rn (Read All Registers)
%Un (Clear Serial Port Speed)
%V (Display Modem Firmware Version)
Ampersand Command Set
&Cn (Serial Port DCD Control)
&Dn (DTR Control)
&F (Restore Command Defaults)
&Gn (Guard Tone)
&Pn (Dial Pulse Ratio)
&Sn (DSR Options)
&Tn (Diagnostic Test Mode)
&W (Store Current Configuration)
Parenthesis Command Set
)Mn (Power Level Adjustment for Cellular Telephone Connections)
Asterisk Command Set
*I (Modem Identifier)
*W (Store Complete Configuration)
Hyphen Command Set
-D{dial string} (Repeat Dial)
-En (Modem Port Data Length)
-Hn (Dumb Mode)
-In (Country Code)
Changing Country Codes on Microcom Modems
Configure
Verify
-Jn (Detect Phase)
-Kn (MNP Extended Services)
-Mn (MNP Class Connect Messages)
-On (Serial Port Parity)
-Pn (Check Parity)
-Qn (Fallback Modulation Speed)
-V (Split Modem Port Speed with Multiprotocol Autoanswer)
Colon Command Set
:Dn (Manual Dial)
:En (Compromise Equalizer)
:Tn? (Read Configuration Register)
@Character Command Set
@Cn (CTR, DSR, and DCD Connect Message Control)
@E (Detailed Modem Call Status)
@Mn (Select Transmit Level for Cellular Connections)
@Un (Minimum Connection Speed)
Backslash Command Set
\An (Maximum MNP Block Size)
\Bn (Transmit Break)
\Cn (Autoreliable Buffer)
\Dn (Serial Port DSR/CTS Control)
\En (Data Echo)
\F (Display Stored Phone Numbers)
\Gn (Modem Port Flow Control)
\Jn (Bps Rate Adjust)
\Kn (Break Control)
\Nn (Operating Mode)
\Pn{dial string} (Store a Telephone Number)
\ Qn (Serial Port Flow Control)
\Rn (Serial Port Ring Indicator)
\Sn (Read Online Status)
\Tn (Inactivity Timer)
\Vn (Error Correction Result Code Form)
Connection Result Code Tables
\Wn (Split Serial Port Speed)
\Xn (XON/XOFF Passthrough)
# Character Command Set
#En (Answer Mode Escape Sequence)
Modem S and :T Register Summary
Read All Registers
Point to a New Reference Register
Read a Configuration Register
Change the Value of a Register
Display the Value of the Reference Register
Change the Value of the Reference Register
S Register Descriptions
S0 (Ring to autoanswer On)
S1 (Ring Counter)
S2 (Escape Code Character)
S3 (Carriage Return Character)
S4 (Line Feed Character)
S5 (Backspace Character)
S6 (Wait Before Dialing)
S7 (Wait for Carrier After Dial)
S8 (Pause Time for Dial Delay)
S9 (Carrier Detect Response Time)
S10 (Delay for Hangup After Carrier Loss)
S11 (DTMF Tone-Dialing Speed)
S12 (Escape Code Guard Time and Remote Access Attention Sequence Guard Time)
S14 (Bit-Mapped Register)
S16 (Bit-Mapped Register for Test Options)
S18 (Test Timer)
S21 (Bit-Mapped Register)
S22 (Bit-Mapped Register)
S23 (Bit-Mapped Register)
S25 (Delay to DTR and Asynchronous/Synchronous Time Delay)
S27 (Bit-Mapped Register)
:T Register Descriptions
:T0 (Timer for V.22 bis, V.22, and V.32 Modes During Multi-Protocol Answer)
:T3 (Timer for V.21 and V.23 Answer Tone Duration)
:T4 (Timer for Line Turnaround Delay and Carrier On)
:T6 (Timer for DCD Turn On Delay)
:T9 (Primary XON Flow Control Character)
:T10 (Primary XOFF Flow Control Character)
:T11 (Secondary XON Flow Control Character)
:T12 (Secondary XOFF Flow Control Character)
:T14 (Connect Message Delay Timer)
:T16 (CTS Turn On Delay Timer)
:T17 (V.32/V.32 bis Connection Training Timer)
:T19 (Bit-Mapped Register)
:T22 (DSR Timer)
:T23 (Bit-Mapped Register)
:T26 (Bit-Mapped Register)
:T51
:T52
:T89 (PoS Configuration)
:T110 (Select V.8 or V.8 bis Modem Exchange Register)
:T114 (56KFlex Control Register)
:T120 (Answerback Tone Duration)
:T121 (Answerback Tone Configuration for PoS)
:T124 (K56PLUS/V.90 Control)
:T127
Debugging
PoS Support
PoS Field Applications
Example of Modemcap Creation, Assignment, Audit
V.90 56K AT Command Set Support
%Mn
%M4
%M3
%M2
%M1
%M0
%Gn%Bn
Baud Rate Interaction Example
Cisco Connection Online
AT Command Set and Register Summary for V.34, 56K, and V.90 12-Port Modules
April 25, 2002
This document describes AT commands and S and :T registers for the following universal access server modules:
•
V.34 12-port module
–V.34 modulation, 28.8 kbps, firmware version 1.x.xx
–V.34 annex 12 modulation, 33.6 kbps, firmware version 2.x.xx
•56K 12-port module
–K56flex modulation, 56 kbps, firmware version 3.x.xx
•56K 12-port module
–K56flex and V.90 modulation, 56 kbps firmware version 5.x.xx
See "V.90 56K AT Command Set Support," page 86 for specific information pertaining to the AT command set which supports the K56flex and V.90 speeds. These commands are in support of firmware version 5.x.xx (use the show modem version command).
Note Except where noted, this document lists defaults and descriptions for the latest firmware, that is version 3.2.20 (for 56K 12-port modules) and version 2.3.6 (for V.34 12-port modules). For defaults for previous firmware versions, see the universal access server modem firmware release notes, which are available on the World Wide Web at http://www.cisco.com, http://www-china.cisco.com, or http://www-europe.cisco.com.
Note For Point of Sale (PoS) support, make sure that the 12-port board is running firmware version 3.2.10 or later (use the show modem version command).
Note Customers using Cisco IOS Release 12.0(4)XI1 or higher will be prompted to use the Service Processing Element (SPE) command instead of the modem-pool command to download code. The modem-pool command will no longer be available, and the existing modem firmware configurations in the router will be converted to the new spe command format. See the Cisco document, SPE and Firmware Download Enhancements at the following URL for more information about the spe command:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t7/spe1206t.htm
If you have questions or need help, refer to the last section "Cisco Connection Online" for further information.
This document contains the following sections:
•Entering AT Commands
•Alphabetic Command Set
•^ Caret Command Set
•$ Dollar Command Set
•% Percent Command Set
•& Ampersand Command Set
•) Parenthesis Command Set
•* Asterisk Command Set
•- Hyphen Command Set
•: Colon Command Set
•@Character Command Set
•\ Backslash Command Set
•# Character Command Set
•Modem S and :T Register Summary
•S Register Descriptions
•:T Register Descriptions
•PoS Support
•Cisco Connection Online
Entering AT Commands
Keep in mind the following guidelines when you send AT commands to a modem:
•Entering AT command mode involves two main configuration tasks: configuring a manageable modem to permit a direct-connect session and then establishing the session. Table 1 describes all the steps necessary to enter AT command mode on the access server.
Table 1 AT Commands
Step
|
Command
|
Purpose
|
1
|
access server> enable
Password: <password>
access server#
|
Enter privileged EXEC (enable) mode.
Enter the password.
You have entered privileged EXEC mode when the access server# prompt appears.
|
2
|
access server# config term
Enter configuration commands, one per line. End with CNTL/Z.
access server(config)#
|
Enter global configuration mode. You have entered global configuration mode when the access server(config)# prompt appears.
|
3
|
access server(config)# line 1
access server(config-line)#
|
Enter line configuration mode. In this example, line 1 is specified. You have entered line configuration mode when the access server(config-line)# prompt appears.
|
4
|
access server(config-line)# modem at-mode-permit
|
Configure a manageable modem to permit a direct-connect session.
|
5
|
access server(config-if)# end
access server#
%SYS-5-CONFIG_I: Configured from console by console <Return>
access server#
|
Return to privileged EXEC mode.
When this message appears, press Return to get the access server# prompt.
|
6
|
access server# modem at-mode 1/1
You are now entering AT command mode on modem (slot 1 / port 1).
Please type CTRL-C to exit AT command mode.
|
Enter a direct-connect session with a modem. In this example, a direct-connect session is established with the modem in slot 1, port 1. Enter the modem slot number first, followed by the modem port number.
Now you are in AT command mode and can enter the AT commands described in this document.
|
7
|
<Ctrl> <c>
access server#
|
When you are finished entering AT commands, press Ctrl-C to exit AT command mode and return to privileged EXEC mode.
|
Note ATA, ATO, ATD, and all dial modifiers are not valid in direct-connect sessions.
•To exit a direct-connect session with a modem, press Ctrl-C.
•All commands except A/ (Repeat Last Command) and +++ (Escape Code) are preceded by the AT prefix and are executed when you press Return or Enter.
•Enter commands as either uppercase or lowercase, not mixed case.
•Commands are limited to 98 characters, not including the AT prefix, Return, and space characters.
•A missing numeric argument is assumed to be zero. For example, the Data Echo command \E is equivalent to \E0.
•The modem operates in one of two modes: idle state (no connection established with another modem) or connect state. Use the following commands to change operating states:
–To enter command state from connect state without breaking the connection, enter +++ (Escape Code) without pausing and do not press Return.
–To return to connect mode, enter AT0 and press Return.
Note The default for the #E command is #E1, which means that the escape code sequence is disabled in answer mode. For more information, refer to the section, "# Character Command Set," on page 60.
Alphabetic Command Set
This section describes modem commands that begin with an alphabetic (A to Z) character.
A (Answer)
Forces the modem off-hook in answer mode, regardless of the value of register S. If result codes are enabled, the workstation displays RING (long form) or 2 (short form) when it receives a call.
A/ (Repeat Last Command)
Reexecutes the last command one time. A/ is not preceded by the AT prefix and is not followed by a Return.
AT (Attention)
Informs the modem that commands are being sent to it. AT must precede all other commands except A/ and +++.
Bn (ITU/Bell Mode)
Selects the ITI-U/Bell connection mode used when connecting at 300 and 1200 bps. Bn is ignored when the modem port is set to other speeds. Table 2 lists command options.
Table 2 ITI-U/Bell Mode Command Options
Command
|
Meaning
|
B0
|
ITU V.22 standard at 300 and 1200 bps, international default1
|
B1
|
Bell 212A standard at 300 and 1200 bps, USA default1
|
D {dial string} (Dial)
Dials a telephone number to establish a connection. The Dial command must be the last command on the command line. The dial string can contain up to 98 characters; valid characters are the digits 0 to 9, the dial modifiers listed in Table 3, and # and * for tone dialing. The modem ignores invalid characters; dial strings longer than 98 characters return an error. For example, to dial the telephone number 1 617 555 1234, enter the following command:
To cancel the Dial command, press any key or set Data Terminal Ready (DTR) to off unless &D0 (DTR ignored) is set. After disconnect, there is a five-second delay before the modem is set off-hook in originate mode.
Dial Modifiers
The dial modifiers listed in Table 3 add conditions to the telephone number that you are dialing. You can use several dial modifiers with the same telephone number, and, unless otherwise noted, you can place dial modifiers anywhere in the dial string.
Table 3 Dial Modifiers
Modifier
|
Meaning
|
^A
|
Performs link negotiation at 4800 bps for this connection only. This dial modifier is equivalent to the *H2 command (link negotiation at 4800 bps).
|
J
|
Performs link negotiation at 1200 bps for this connection only. This dial modifier is equivalent to the *H1 command (link negotiation at 1200 bps).
|
K
|
Adjusts the power level for a single cellular connection.This option is used for modems attached to cellular interfaces.
|
L
|
Redials the last telephone number.
|
M
|
Dials in Link Access Procedure for Modem (LAPM) Mode for this connection only.
|
Nn
|
Dials an alternate stored number. This modifier must follow the last character in a dial string. If the modem fails to make a connection, the Nn modifier dials alternate telephone number n (where n is a number between 1 and 9) stored in the directory by the &Z or \Pn command (Store Telephone Number). If you do not enter a value for n, the modem dials the first stored entry. For example, to dial the third stored telephone number as an alternate telephone number, enter the following command and press Return:
The Nn modifier can also be stored in the directory at the end of a dial string. If you do not specify a value for n and the modem fails to make a connection, it dials the number in the next position, even if it is null. Stored number 1 follows stored number 9.
For example, to store a telephone number and an alternate number in directory entry 4, enter the following command and press Return:
|
Q
|
Dials in LAPM mode for this connection only with fallback to normal mode.
|
R
|
Dials a number in answer mode when calling an originate-only modem. The modifier must follow the last character in the dial string. For example, to dial the telephone number 5552345 in answer mode, enter the following command and press Return:
|
S
|
Dials the telephone number stored as entry 1 with the &Z or \P1 command. The telephone number is displayed as it is dialed. The S modifier must immediately follow D in the dial command. You cannot add the S modifier to the phone number stored in the first directory position. For example, to dial the first stored telephone number, enter the following command and press Return:
|
T
|
Tone-dials the number. The last P or T dial modifier used remains in effect until you enter a new P or T modifier or reset the modem. You can combine P and T dial modifiers within a dial string. For example, to pulse-dial a local telephone number and tone-dial an access code and telephone number, enter the following command and press Return:
|
U
|
Dials in direct mode. The U modifier overrides the current operating mode and dials in direct mode for that connection only. For example, enter the following command and press Return:
|
V
|
Dials in LAPM mode with fallback to MNP for this connection only. For example, enter the following command and press Return:
|
W
|
Waits for dial tone before dialing. The W modifier is inserted between digits in a dial string. The modem then waits for the time specified in register S7. If it receives a dial tone before the time delay expires, it continues dialing; otherwise, it returns NO DIALTONE and hangs up. For example, enter the following command and press Return:
|
X
|
Dials in autoreliable mode for this connection only. For example, enter the following command and press Return:
|
Y
|
Dials in MNP reliable mode for this connection only. For example, enter the following command and press Return:
|
Z
|
Dials in normal mode for this connection only. For example, enter the following command and press Return:
|
/n
|
Dials one of the nine telephone numbers stored in the directory by the &Z or \Pn command (where n is a number between 1 and 9). The telephone number is displayed as it is dialed.
|
,
|
Pauses during dialing for the time specified in register S8 before dialing the next digit. Use more than one comma for a longer pause. For example, use the comma when you need to dial 9 and then wait for another dial tone before dialing an outside line:
|
@
|
Waits for quiet answer before dialing. This modifier is inserted between characters in a dial string. The modem waits for the time specified in register S7 for at least one ring, followed by 5 seconds of silence, before acting on the next character in the dial string. If the modem does not detect this sequence, it returns a NO ANSWER result code and hangs up. Use this modifier when the system you are calling does not provide a dial tone. For example:
|
!
|
Sets the modem on-hook for one-half second and then back off-hook. This is equivalent to depressing the switch-hook button on your telephone.
|
;
|
Returns to command state after dialing. Add this modifier to the end of a dial string. The modem remains in command state after it dials the digits preceding the semicolon, so that you can enter dial strings longer than 98 characters. Each dial command except the last one must end with a semicolon. After the final dial command is entered, the modem tries to establish a connection. To abort dialing before attempting to establish a connection, enter the H command (Hang Up). For example:
|
En (Command Echo)
Configures the modem to echo commands to the workstation. Table 4 lists command options.
Default
E1
Table 4 Command Echo Options
Command
|
Meaning
|
E0
|
Disables echoing commands to the workstation
|
E1
|
Enables echoing commands to the workstation
|
H (Hang Up)
Disconnects from the remote system and hangs up the telephone line. If the %Dn (Disconnect Buffer Delay) time is nonzero, the hangup can be delayed until the modem has transmitted all data in its transmit buffer.
In (Identification)
Displays modem information and results of checksum tests on firmware. Table 5 lists identification command options.
Table 5 Identification Command Options
Command
|
Meaning
|
I0
|
Displays the four-digit modem product code
|
I1
|
Runs a checksum on firmware ROM and displays the three-digit result
|
I2
|
Runs a checksum on firmware ROM and displays the checksum status
|
I3
|
Displays the modem name and revision level.
|
On (Enter Connect State)
Sets the modem to connect state. Table 6 lists command options.
Table 6 Connect State Command Options
Command
|
Meaning
|
O0
|
Enters connect state.
|
O1
|
Begins an equalizer retrain sequence when operating at 2400 bps or higher and then returns to connect state. Use the O1 command to reduce loss of equalization because of excessive bit error rates.
|
Qn (Quiet)
Configures the modem to send result and status codes, such as OK, BUSY, and RING, to your workstation. Table 7 lists command options.
Default
Q0
Table 7 Quiet Mode Command Options
Command
|
Meaning
|
Q0
|
Enables output of result codes.
|
Q1
|
Disables output of result codes.
|
Q2
|
Disables only answer mode result codes. Status report messages are not affected.
|
Sn? (Read Configuration Register)
Displays the contents of S register n (where n is a decimal number).
Range
0 to 27
Default
S0
T (Tone Dial)
Sets the current dialing mode to tone. This is the default dialing mode.
Vn (Result Code Form)
Selects the result code format sent to your workstation. The \Vn command (Error Correction Result Code Form) modifies the connect messages to reflect a reliable link connection. Table 8 lists command options.
Default
V1
Table 8 Result Code Form Command Options
Command
|
Meaning
|
V0
|
Sends short form result codes
|
V1
|
Sends long form result codes
|
Wn (Connection Speed Reporting)
Displays the serial port or modem port speed in connect messages. When the X0 command (Extended Result Codes) is set, CONNECT displays for any Wn command option. Table 9 lists command options.
Default
W2
Table 9 Connection Speed Reporting Command Options
Command
|
Meaning
|
W0
|
Displays serial port connect messages
|
W1
|
Displays serial port connect messages
|
W2
|
Displays modem port connect messages
|
Xn (Extended Result Codes)
Selects the extended result code format sent to the workstation. Table 10 lists command options.
The following commands also affect the result code format:
•The Vn command (Result Code Form) selects short or long form result codes.
•The \Vn command (Result Code Form) or -M1 command (MNP Class Connect Messages) must be set to indicate MNP reliable mode in the result code.
When the modem is set to ignore dial tone, it waits for the register S6 time delay and dials with or without a dial tone.
Default
X4
Note The W dial modifier causes a wait for dial tone regardless of the Xn command setting.
Table 10 Extended Result Code Command Options
Command
|
Meaning
|
X0
|
Sends a connect result code when a connection is established. The modem ignores dial tone and busy signals.
|
X1
|
Sends a connect result code reflecting the bps rate when a connection is established. The modem ignores dial tone and busy signals.
|
X2
|
Sends a connect result code reflecting the bps rate when a connection is established. The modem sends a NO DIALTONE result code if dial tone is not detected within 5 seconds of a dial attempt. The modem ignores busy signals.
|
X3
|
Sends a connect result code reflecting the bps rate when a connection is established. The modem sends a BUSY result code if a busy signal is detected. The modem ignores dial tone.
|
X4
|
Sends a connect result code reflecting the bps rate when a connection is established. The modem sends a NO DIALTONE result code if dial tone is not detected within 5 seconds of a dial attempt. The modem sends a BUSY result code if a busy signal is detected.
|
Yn (Long Space Disconnect)
Configures the modem to send a four-second Break on receipt of an H command (Hang Up). The answering modem disconnects if it receives the Break. This command is used only in normal and direct connections. Table 11 lists command options.
The four-second Break is also sent if Y1 and one of the following &Dn commands (Data Terminal Ready Control) are set:
•&D2 is set and DTR drops.
•&D3 is set and DTR drops. The sending modem disconnects after the Break.
Default
Y0
Table 11 Long Space Disconnect Command Options
Command
|
Meaning
|
Y0
|
Disables long space disconnect on receipt of an H command. The normal break signal is sent.
|
Y1
|
Enables long space disconnect on receipt of an H command. Y1 must be set on both modems for this command to take effect.
|
Z (Reset)
Hangs up the telephone line, clears the modem and the serial port buffers, and restores any settings stored with the &W or *W commands. If no settings are stored, the command restores the factory default (&F) settings.
Caret Command Set
This section describes modem commands that begin with a caret (^) character.
^H (Host Port Upgrade)
Copies new firmware from a computer file to the modem's Flash memory.
^V (Display Bootstrap Revision)
Displays the modem's current Flash memory bootstrap revision.
Dollar Command Set
This section describes modem commands that begin with a dollar ($) character.
$Bn (Serial Port Bps Rate)
Sets the serial port rate to n bps.
Range
300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 bps
Default
$B115200
$D (Power-Up Diagnostics)
Runs power-up diagnostics.
Percent Command Set
This section describes modem commands that begin with a percent (%) character.
Note Modifications have been made to certain percent (%) AT commands as a result of enhancements made to the firmware version 5.0.4. Changes affect commands %B, %Gn, %G1, and %M.
%An (Autoreliable Fallback Character)
Specifies the ASCII character recognized as the autoreliable fallback character on the answering modem. In autoreliable mode, when the modem encounters an incoming autoreliable fallback character from the remote system, it automatically switches to normal mode and passes the character to the serial port. Autoreliable fallback character recognition stops if the modem receives a SYN character (decimal 22). The \N3 (Operating Mode) and \C2 (Autoreliable Buffer) commands must also be set.
Caution Do not use the settings
n = 63 or
n = 126. They interfere with V.42.
Range
0 to 127 (ASCII decimal)
Default
%A0 (autoreliable fallback character is disabled)
%Bn (Modem Port Bps Rate)
Sets the modem port data rate. Downshifting can still occur.
Note The user must always set %M before setting the %B option. Setting %M results in %B getting set to the maximum baud rate for that modulation. With AT%G0, setting %M will have no effect on %B. With AT%G1, setting %M will cause the %B to be set to the maximum value in that modulation. See %M (Modulation).
The %Bn command is affected by the following %Gn command (Independent Serial/Modem Port Speed) options:
•If %G0 is sent locally, the modem port speed is matched to the serial port speed, regardless of any previous %Bn setting.
•If %G1 is set, the modem speed changes only when a %Bn command is entered.
Range
300, 600, 1200, 2400, 4800, 7200, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400, 2800, 28800, 29333, 30666, 31200, 32000, 33333, 34000, 34666, 33600, 36000, 37333, 38000, 38666, 40000, 41333, 42000, 42666, 44000, 45333, 46000, 46666, 48000, 49333, 50000, 50666, 52000, 53333, 54000, 54666, 56000 bps
Note Includes V.90 speeds
Default
%B33600 for V.34 modems
%B56000 for 56 kbps modems
%Cn (Compression Control)
Sets the modem to use a data compression method in reliable connections. The recommended default command setting of %C3 allows the modem to establish a reliable connection using V.42 bis compression or MNP Class 5 Data Compression, depending on the capability of the remote modem.
If the remote modem does not support data compression or has data compression disabled, the modem can establish a noncompression connection with any %Cn setting.
Throughput is affected by the \Jn command (Bps Rate Adjust) options:
•\J0 (Disable Bps Rate Adjust) is recommended for the highest throughput.
•\J1 (Enable Bps Rate Adjust) causes the serial port to adjust to 9600 bps when a reliable connection is established at a speed from 2400 to 14400 bps. At 16800 bps or higher, the serial port speed adjusts to 19200 bps.
Default
%C3
Table 12 Compression Control Command Options
Command
|
Meaning
|
%C0
|
Disables data compression.
|
%C1
|
Enables MNP Class 5 data compression only.
|
%C2
|
Enables V.42 bis compression only.
|
%C3
|
Enables V.42 bis compression and MNP Class 5 Data Compression. The modem matches the capability of the remote modem.
|
%Dn (Disconnect Buffer Delay)
Specifies a delay time for the modem to process data in its transmit or receive buffers before disconnecting. When DTR transitions off or an H command (Hang Up) is entered, the modem attempts for n seconds to empty its transmit buffer before disconnecting. When carrier transitions off, the modem attempts for n seconds to empty its receive buffer before disconnecting. If the buffers are empty or if n = 0, the modem disconnects immediately.
If a physical disconnect occurs (for example, the connection is lost), only the receive buffer can be processed. If the delay expires before the modem empties its buffers, or if the modem is in command state at disconnect, data can be lost. The receive buffer may not empty before disconnecting if %E1 (Autoretrain) is set during normal mode connections at 2400 bps or higher.
Range
0 to 255 seconds
Default
%D0
%En (Autoretrain)
Sets the modem to resynchronize (autoretrain) up to three times (for a total of up to 6 seconds) before hanging up. The modem resynchronizes only for connection speeds of 2400 bps or higher. The %En command is ignored in V.32 communication. Table 13 lists command options.
Default
%E1
Table 13 Autoretrain Command Options
Command
|
Meaning
|
%E0
|
Disables the automatic retrain sequence. Use the O1 command (Enter Connect State) to force the retrain sequence when %E0 is set.
|
%E1
|
Enables the automatic retrain sequence at 2400 bps or higher.
|
%Fn (V.23 Mode)
Configures the modem for V.23 mode. Table 14 lists the V.23 command options.
Default
%F0
Table 14 V.23 Command Options
Command
|
Meaning
|
%F0
|
Allows multiprotocol answering; disables V.23 mode on the originate modem
|
%F1
|
75-bps transmit, 1200-bps receive (split speed) V.23 operation
|
%F2
|
1200-bps transmit, 75-bps receive (split speed) V.23 operation
|
%F3
|
1200-bps transmit, 1200-bps receive (half duplex) V.23 operation
|
%Gn (Independent Serial Port and Modem Port Speed)
Sets the modem port speed independent of the serial port speed. The modem port speed is set by the %Bn command (Modem Port Bps Rate). Table 15 lists command options.
Default
%G0
Table 15 Independent Serial and Modem Port Speed Command Options
Command
|
Meaning
|
%G0
|
Updates the serial and modem port speeds each time an AT command is entered. The serial port speed determines the modem port speed.
|
%G1
|
Updates the modem port speed only when a %Bn (Modem Port Bps Rate) command is entered.
|
The following tables list command strings for setting modem port speeds:
•Table 16 lists commands for modem protocols up to 14400 bps.
•Table 17 lists commands for V.34 modem port speeds up to 33600 bps.
•Table 18 lists commands for 56 kbps modem port speeds up to 56000 bps.
Table 16 Modem Protocol Commands
Protocol
|
%G0
|
%G1
|
V.21 (300 bps)
|
Using B0 at 300 bps
|
B0%B300
|
Bell 103 (300 bps)
|
Using B1 at 300 bps
|
B1%B300
|
V.22 (600 bps)
|
At 600 bps
|
%B600
|
V.22 (1200 bps)
|
Using B0 at 1200 bps
|
B0%B1200
|
Bell 212A (1200 bps)
|
Using B1 at 1200 bps
|
B1%B1200
|
V.22 bis (2400 bps)
|
At 2400 bps
|
%B2400
|
V.32 (4800 bps)
|
At 4800 bps
|
%B4800
|
V.32 (9600 bps)
|
At 9600 bps
|
%B9600
|
V.32 bis (14400 bps)
|
At 14400 bps
|
%B14400
|
V.FC (38800 bps)
|
At 28800 bps
|
%B28800
|
Table 17 V.34 Commands
When %M2 or %M3 Is Set:
|
V.34 Speed
|
%G1
|
2400 bps
|
%B24001
|
4800 bps
|
%B4800
|
7200 bps
|
%B7200
|
9600 bps
|
%B9600
|
12000 bps
|
%B12000
|
14400 bps
|
%B14400
|
16800 bps
|
%B16800
|
19200 bps
|
%B19200
|
21600 bps
|
%B21600
|
24000 bps
|
%B24000
|
26400 bps
|
%B26400
|
28800 bps
|
%B28800
|
31200 bps
|
%B31200
|
33600 bps
|
%B33600
|
When %M3 Is Set:
|
| |
56 kbps Speed
|
%G1
|
| |
32000 bps
|
%B32000
|
| |
34000 bps
|
%B34000
|
| |
36000 bps
|
%B36000
|
| |
38000 bps
|
%B38000
|
| |
40000 bps
|
%B40000
|
| |
42000 bps
|
%B42000
|
| |
44000 bps
|
%B44000
|
| |
46000 bps
|
%B46000
|
| |
48000 bps
|
%B48000
|
| |
50000 bps
|
%B50000
|
| |
52000 bps
|
%B52000
|
| |
54000 bps
|
%B54000
|
| |
56000 bps
|
%B56000
|
When %M4 Is Set:
|
| |
56 kbps Speed
|
%G1
|
| |
28000 bps
|
%B2800
|
| |
29333 bps
|
%B29333
|
| |
30666 bps
|
%B30666
|
| |
32000 bps
|
%B32000
|
| |
33333 bps
|
%B33333
|
| |
34000 bps
|
%B34000
|
| |
34666 bps
|
%B34666
|
| |
36000 bps
|
%B36000
|
| |
37333 bps
|
%B37333
|
| |
38000 bps
|
%B38000
|
| |
38666 bps
|
%B38666
|
| |
40000 bps
|
%B40000
|
| |
41333 bps
|
%B41333
|
| |
42000 bps
|
%B42000
|
| |
42666 bps
|
%B42666
|
| |
44000 bps
|
%B44000
|
| |
56 kbps Speed
|
%G1
|
| |
45333 bps
|
%B45333
|
| |
46000 bps
|
%B46000
|
| |
46666 bps
|
%B46666
|
| |
48000 bps
|
%B48000
|
| |
49333 bps
|
%B49333
|
| |
50000 bps
|
%B50000
|
| |
50666 bps
|
%B50666
|
| |
52000 bps
|
%B52000
|
| |
53333 bps
|
%B53333
|
| |
54000 bps
|
%B54000
|
| |
54666 bps
|
%B54666
|
| |
56000 bps
|
%B56000
|
%Ln (Speed Matching)
Configures the modem to use speed matching when establishing a connection. Table 18 lists command options.
Default
%L1
Table 18 Speed Matching Command Options
Command
|
Meaning
|
%L0
|
Provides partial speed matching
|
%L1
|
Enables speed matching
|
%L2
|
Disables speed matching
|
%L3
|
Enables V.8 automode with fallback to ITU-T1 automode
|
%L4
|
Enables V.8 automode only
|
Modem Connection Modes Using Speed Matching
The following tables list connections the modem can establish with %L1 or %L3 set.
•Table 19—lists connections if a 56K modem in the access server originates the call.
•Table 20—lists connections if a 56K modem in the access server answers the call.
•Table 21—lists connections if a V.34 modem in the access server originates the call.
•Table 22—lists connections if a V.34 modem in the access server answers the call.
Table 19 56K Modem Originates Call
Mode Setting on Originating Access Server 56K Modem
|
Mode Setting on Answering Modem
|
Bell 103
|
Bell 212A
|
V.22[b]
|
V.22[a]
|
V.22 bis
|
V.32
|
V.32 bis
|
V.FC
|
V.34
|
K56flex/
V.90
|
K56flex (32000-56000)
V.90 (28000-56000)
|
-
|
V.22[a]
|
-
|
-
|
V.22 bis
|
V.32
|
V.32 bis
|
V.FC
|
V.34
|
K56flex1
|
V.34 annex 12- (31200-33600)
|
|
V.22[a]
|
-
|
-
|
V.22 bis
|
V.32
|
V.32 bis
|
V.FC
|
V.34
|
V.34
|
V.34 (2400-28800)
|
-
|
V.22[a]
|
-
|
V.22[a]
|
V.22 bis
|
V.32
|
V.32 bis
|
V.FC
|
V.34
|
V.34
|
V.FC (14400-28800)
|
-
|
V.22[a]
|
-
|
V.22[a]
|
V.22 bis
|
V.32
|
V.32 bis
|
V.FC
|
V.FC
|
V.FC2
|
V.32 bis (4800-14400)
|
-
|
V.22[a]
|
-
|
V.22[a]
|
V.22 |
