AT Command Set and Register Summary for
Analog Modem Network Modules

This document describes AT commands and S and :T registers for 8-port and 16-port analog modem network modules for the Cisco 2600 and Cisco 3600 series of modular routers.

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This document contains the following sections:

Entering AT Commands

Table 1 shows how to enter AT command mode.

Table 1: Entering AT Command Mode
Step Command Purpose

1
Router> enable

Password: <password>

Router#

Enter privileged EXEC (enable) mode.

Enter the password.

You have entered privileged EXEC mode when the Router# prompt appears.

2
Router# telnet 172.16.1.10 2001

Enter the IP address of your LAN interface. The port unmber is 2000 + n, where n is the line number of the modem. You can now enter AT commands.

3
Ctrl-Shift-6 x

To suspend a Telnet session, press Ctrl-Shift-6 x.

4
Router# where

When you are finished, enter the where command to check for open sessions.

5
Router# disconnect line 1

Closing connection to 172.16.1.10 [confirm] y

Router#

To disconnect a session, enter the disconnect command.

**Table 1: Entering AT Command Mode**
Step	Command	Purpose
1	Router`>` enable Password: <password> Router`#`	Enter privileged EXEC (enable) mode. Enter the password. You have entered privileged EXEC mode when the `Router#` prompt appears.
2	Router`#` telnet 172.16.1.10 2001	Enter the IP address of your LAN interface. The port unmber is 2000 + n, where n is the line number of the modem. You can now enter AT commands.
3	Ctrl-Shift-6 x	To suspend a Telnet session, press Ctrl-Shift-6 x.
4	Router# where	When you are finished, enter the where command to check for open sessions.
5	Router`#` disconnect line 1 Closing connection to 172.16.1.10 [confirm] y Router#	To disconnect a session, enter the disconnect command.

Note ATA, ATO, ATD, and all dial modifiers are invalid in direct-connect sessions.

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, but 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 "# Character Command Set" section.

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)

Repeats the last command. A/ is not preceded by the AT prefix and is not followed by 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

¹ Default is determined by country setting.

**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:

D 16175551234

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:

ATD 55554321N3
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:

AT\P4 5551234N3

P

Pulse-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:

ATD P12345 T335 6789
NotePulse dialing is not supported in Japan.

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:

ATD 5552345R

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:

ATDS

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:

ATD P12345 T335 6789
NotePulse dialing is not supported in Japan.

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:

ATD 12345U

V

Dials in LAPM mode with fallback to MNP for this connection only. For example, enter the following command and press Return:

ATD 12345V

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:

ATD 12345 W 67890

X

Dials in autoreliable mode for this connection only. For example, enter the following command and press Return:

ATD 12345X

Y

Dials in MNP reliable mode for this connection only. For example, enter the following command and press Return:

ATD 12345Y

Z

Dials in normal mode for this connection only. For example, enter the following command and press Return:

ATD 12345Z

/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:

ATD 9,,5552345

@

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:

ATD 5551234 @ 43210

!

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:

ATD 9,12345; OK ATD 78989 @ 12345 W 344

**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: ATD 55554321N3 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: AT\P4 5551234N3
P	Pulse-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: ATD P12345 T335 6789 NotePulse dialing is not supported in Japan.
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: ATD 5552345R
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: ATDS
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: ATD P12345 T335 6789 NotePulse dialing is not supported in Japan.
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: ATD 12345U
V	Dials in LAPM mode with fallback to MNP for this connection only. For example, enter the following command and press Return: ATD 12345V
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: ATD 12345 W 67890
X	Dials in autoreliable mode for this connection only. For example, enter the following command and press Return: ATD 12345X
Y	Dials in MNP reliable mode for this connection only. For example, enter the following command and press Return: ATD 12345Y
Z	Dials in normal mode for this connection only. For example, enter the following command and press Return: ATD 12345Z
/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: ATD 9,,5552345
@	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: ATD 5551234 @ 43210
!	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: ATD 9,12345; OK ATD 78989 @ 12345 W 344

Blacklisting

In Japan only, the analog modem network modules provide the blacklisting feature. If no remote modem is detected in three dial attempts to the same number in a three-minute period, the originating modem is prevented from dialing that number for the next three minutes.

En (Command Echo)

Configures the modem to echo commands to the workstation. Table 4 lists command options.

Default

Table 4: Command Echo Options
Command Meaning

E0

Disables echoing commands to the workstation

E1

Enables echoing commands to the workstation

**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.

**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.

**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

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.

**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

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

Table 8: Result Code Form Command Options
Command Meaning

V0

Sends short form result codes

V1

Sends long form result codes

**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 is displayed for any Wn command option. Table 9 lists command options.

Default

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

**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

Note The W dial modifier causes a wait for dial tone regardless of the Xn command setting.

Table 10: Extended Result Codes 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.

**Table 10: Extended Result Codes 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

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.

**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.

%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 You must set %M before setting %B. With AT%G0, setting %M has no effect on %B. With AT%G1, setting %M causes %B to be set to the maximum data rate for that modulation. See the "%M (Modulation)" section .

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, 28800, 31200, 33600 bps

Default

%B33600

%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.

**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.

**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

**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.

**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 modem port speeds up to 33600 bps.

Table 16: Modem Port Speed Commands to 14400 Bps
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

Table 16: **Modem Port Speed Commands to 14400 Bps**
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

Table 17: Modem Port Speed Commands
When %M2 Is Set:

Modem 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

¹In answer mode, this results in V.22 bis connection.

**Table 17: Modem Port Speed Commands**
When %M2 Is Set:
Modem 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

%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

¹International Telecommunications Union Telecommunication Standardization sector.

**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 modem in the router originates the call.
Table 20---lists connections if a modem in the router answers the call.

Table 19: Modem Connection Modes with %L1 or %L3 Set---Router Modem Originating
Mode Setting on Originating 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.34 K56flex

V.34 annex 12 (31200-33600)

V.22 bis

V.32

V.32 bis

V.34

V.34

V. 34 (2400-28800)

V.22[a]

V.22 bis

V.32

V.32 bis

V.34

V.34

V.32 bis (4800-14400)

-

V.22[a]

-

V.22[a]

V.22 bis

V.32

V.32 bis

V.32 bis

V.32 bis

V.32 (4800-9600)

-

V.22[a]

-

V.22[a]

V.22 bis

V.32

V.32

V.32

V.32

V.22 bis (2400)

-

V.22[a]

-

V.22[a]

V.22 bis

V.22 bis

V.22 bis

V.22 bis

V.22 bis

V.22[a] (1200)

-

V.22[a]

-

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[b] (600)

-

-

V.22[b]

-

-

-

-

-

-

V.23[a] (xmt 75)

-

-

-

V.23[b]

V.23[b]

V.23[b]

V.23[b]

V.23[b]

V.23[b]

V.23[b] (xmt 1200)

-

-

-

-

-

-

-

-

-

V.21(75-300)

-

V.22[a]

-

V.21

V.21

V.21

V.21

V.21

V.21

Bell 212A (1200)

Bell 212A

Bell 212A

-

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[a]

Bell 103 (300)

Bell 103

Bell 103

-

Bell 103

Bell 103

Bell 103

Bell 103

Bell 103

Bell 103

**Table 19: Modem Connection Modes with %L1 or %L3 Set---Router Modem Originating**
Mode Setting on Originating 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.34	K56flex
V.34 annex 12 (31200-33600)					V.22 bis	V.32	V.32 bis	V.34	V.34
V. 34 (2400-28800)				V.22[a]	V.22 bis	V.32	V.32 bis	V.34	V.34
V.32 bis (4800-14400)	-	V.22[a]	-	V.22[a]	V.22 bis	V.32	V.32 bis	V.32 bis	V.32 bis
V.32 (4800-9600)	-	V.22[a]	-	V.22[a]	V.22 bis	V.32	V.32	V.32	V.32
V.22 bis (2400)	-	V.22[a]	-	V.22[a]	V.22 bis	V.22 bis	V.22 bis	V.22 bis	V.22 bis
V.22[a] (1200)	-	V.22[a]	-	V.22[a]	V.22[a]	V.22[a]	V.22[a]	V.22[a]	V.22[a]
V.22[b] (600)	-	-	V.22[b]	-	-	-	-	-	-
V.23[a] (xmt 75)	-	-	-	V.23[b]	V.23[b]	V.23[b]	V.23[b]	V.23[b]	V.23[b]
V.23[b] (xmt 1200)	-	-	-	-	-	-	-	-	-
V.21(75-300)	-	V.22[a]	-	V.21	V.21	V.21	V.21	V.21	V.21
Bell 212A (1200)	Bell 212A	Bell 212A	-	V.22[a]	V.22[a]	V.22[a]	V.22[a]	V.22[a]	V.22[a]
Bell 103 (300)	Bell 103	Bell 103	-	Bell 103	Bell 103	Bell 103	Bell 103	Bell 103	Bell 103

Table 20: Modem Connection Modes with %L1 or %L3 Set---Router Modem Answering
Mode Setting on Originating 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.34

K56flex (32000-56000)

V.22 bis

V.32

V.32 bis

V.34

V.34 annex 12 (31200-33600)

V.22 bis

V.32

V.32 bis

V.34

V. 34 (2400-28800)

V.22[a]

V.22 bis

V.32

V.32 bis

V.34

V.32 bis (4800-14400)

-

V.22[a]

-

V.22[a]

V.22 bis

V.32

V.32 bis

V.32 bis

V.32 (4800-9600)

-

V.22[a]

-

V.22[a]

V.22 bis

V.32

V.32

V.32

V.22 bis (2400)

-

V.22[a]

-

V.22[a]

V.22 bis

V.22 bis

V.22 bis

V.22 bis

V.22[a] (1200)

-

V.22[a]

-

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[b] (600)

-

-

V.22[b]

-

-

-

-

-

V.23[a] (xmt 75)

-

-

-

V.23[b]

V.23[b]

V.23[b]

V.23[b]

V.23[b]

V.23[b] (xmt 1200)

-

-

-

-

-

-

-

-

V.21(75-300)

-

V.22[a]

-

V.21

V.21

V.21

V.21

V.21

Bell 212A (1200)

Bell 212A

Bell 212A

-

V.22[a]

V.22[a]

V.22[a]

V.22[a]

V.22[a]

Bell 103 (300)

Bell 103

Bell 103

-

Bell 103

Bell 103

Bell 103

Bell 103

Bell 103

**Table 20: Modem Connection Modes with %L1 or %L3 Set---Router Modem Answering**
Mode Setting on Originating 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.34
K56flex (32000-56000)					V.22 bis	V.32	V.32 bis	V.34
V.34 annex 12 (31200-33600)					V.22 bis	V.32	V.32 bis	V.34
V. 34 (2400-28800)				V.22[a]	V.22 bis	V.32	V.32 bis	V.34
V.32 bis (4800-14400)	-	V.22[a]	-	V.22[a]	V.22 bis	V.32	V.32 bis	V.32 bis
V.32 (4800-9600)	-	V.22[a]	-	V.22[a]	V.22 bis	V.32	V.32	V.32
V.22 bis (2400)	-	V.22[a]	-	V.22[a]	V.22 bis	V.22 bis	V.22 bis	V.22 bis
V.22[a] (1200)	-	V.22[a]	-	V.22[a]	V.22[a]	V.22[a]	V.22[a]	V.22[a]
V.22[b] (600)	-	-	V.22[b]	-	-	-	-	-
V.23[a] (xmt 75)	-	-	-	V.23[b]	V.23[b]	V.23[b]	V.23[b]	V.23[b]
V.23[b] (xmt 1200)	-	-	-	-	-	-	-	-
V.21(75-300)	-	V.22[a]	-	V.21	V.21	V.21	V.21	V.21
Bell 212A (1200)	Bell 212A	Bell 212A	-	V.22[a]	V.22[a]	V.22[a]	V.22[a]	V.22[a]
Bell 103 (300)	Bell 103	Bell 103	-	Bell 103	Bell 103	Bell 103	Bell 103	Bell 103

Restricted Speed Matching

Use the %L0 or %L2 command options on both originating and answering modems to restrict the connection speed. Table 21 lists connection speeds using the %L0 partial speed matching option. Table 22 lists connections speeds using the %L2 speed matching disabled option. If %L2 is set, the modem speed matches the closest possible connection speed.

Table 21: Connection Speeds with Partial Speed Matching (%L0 Option)
Modem Speed Possible Connection Speed

300

300

600

600

200

1200

2400

1200, 2400

4800

4800

7200

4800, 7200

9600

4800, 7200, 9600

12000

4800, 7200, 9600, 12000

14400

4800, 7200, 9600, 12000, 14400

16800

14400, 16800

19200

14400, 16800, 19200

21600

14400, 16800, 19200, 21600

24000

14400, 16800, 19200, 21600, 24000

26400

14400, 16800, 19200, 21600, 24000, 26400

28800

14400, 16800, 19200, 21600, 24000, 26400, 28800

**Table 21: Connection Speeds with Partial Speed Matching (%L0 Option)**
Modem Speed	Possible Connection Speed
300	300
600	600
200	1200
2400	1200, 2400
4800	4800
7200	4800, 7200
9600	4800, 7200, 9600
12000	4800, 7200, 9600, 12000
14400	4800, 7200, 9600, 12000, 14400
16800	14400, 16800
19200	14400, 16800, 19200
21600	14400, 16800, 19200, 21600
24000	14400, 16800, 19200, 21600, 24000
26400	14400, 16800, 19200, 21600, 24000, 26400
28800	14400, 16800, 19200, 21600, 24000, 26400, 28800

Table 22: Connection Speeds with Speed Matching Disabled (%L2 Option)
Modem Speed Possible Connection Speed

300

300

600

600

1200

1200

2400

2400

4800

4800

7200

7200

9600

9600

12000

12000

14400

14400

16800

16800

19200

19200

21600

21600

24000

24000

26400

26400

28800

28800

31200

31200

33600

33600

**Table 22: Connection Speeds with Speed Matching Disabled (%L2 Option)**
Modem Speed	Possible Connection Speed
300	300
600	600
1200	1200
2400	2400
4800	4800
7200	7200
9600	9600
12000	12000
14400	14400
16800	16800
19200	19200
21600	21600
24000	24000
26400	26400
28800	28800
31200	31200
33600	33600

%M (Modulation)

This command sets the upper modulation used in connections. Setting %M causes %B to be set to the maximum data rate for that modulation.

%Mn (Modulation Selection)

This command sets the upper modulation used in connections. Table 23 lists command options.

Default

%M2

Table 23: Modulation Selection Command Options
Command Meaning

%M0

Disables V.34 modulation

V.32 bis, 14.4 kbps maximum

%M1

Disables 33.6 kbps modulation

V.34, 28.8 kbps maximum

%M2

Enables 33.6 kbps modulation

V.34, 33.6 kbps maximum

**Table 23: Modulation Selection Command Options**
Command	Meaning
%M0	Disables V.34 modulation V.32 bis, 14.4 kbps maximum
%M1	Disables 33.6 kbps modulation V.34, 28.8 kbps maximum
%M2	Enables 33.6 kbps modulation V.34, 33.6 kbps maximum

%Rn (Read All Registers)

Displays the contents of modem S and :T registers as a table of values in decimal and hexadecimal format. Table 24 lists command options.

Table 24: Read All Registers Command Options
Command Meaning

%R0

Displays the contents of all S registers as decimal and hexadecimal integers in tabular format

%R1

Displays the contents of all :T registers as decimal and hexadecimal integers in tabular format

**Table 24: Read All Registers Command Options**
Command	Meaning
%R0	Displays the contents of all S registers as decimal and hexadecimal integers in tabular format
%R1	Displays the contents of all :T registers as decimal and hexadecimal integers in tabular format

The following display provides an example of the %R command:

at%r0
 
REG  DEC  HEX    REG  DEC  HEX
S00  001  01H    S14  138  8AH
S01  000  00H    S15  000  00H
S02  043  2BH    S16  000  00H
S03  013  0DH    S17  000  00H
S04  010  0AH    S18  000  00H
S05  008  08H    S19  000  00H
S06  002  02H    S20  000  00H
S07  060  3CH    S21  048  30H
S08  002  02H    S22  118  76H
S09  006  06H    S23  030  1EH
S10  060  3CH    S24  000  00H
S11  075  4BH    S25  005  05H
S12  050  32H    S26  001  01H
S13  000  00H    S27  064  40H
 
S13  000  00H    S27  064  40H
OK

%Un (Clear Serial Port Speed)

Sets the serial port speed. Table 25 lists command options.

Default

%U1

Table 25: Clear Serial Port Speed Options
Command Meaning

%U0

Allows the current serial port speed to be changed to any other speed. This option is not required for speeds of 19200 bps and lower.

%U1

Always keeps the current serial port speed. You must enter %U1 each time you change the serial port speed.

%U2

Allows the current serial port speed to be changed from any speed.

%V (Display Modem Firmware Version )

Displays the modem firmware version and country code. (For country code listings, see Table 37.)

Default

%V1

Table 26: Display Modem Firmware Version Options
Command Meaning

%V1

Provides detail to the x.x.x level

%V0

Provides detail to the x.x level

Ampersand Command Set

This section describes modem commands that begin with an ampersand (&) character.

&Cn (Serial Port DCD Control)

Controls the Data Carrier Detect (DCD) signal level. Use this command if your workstation requires DCD to be off at certain times. Table 27 lists command options. See also the \Dn command.

Default

&C1

Table 27: Serial Port DCD Control Command Options
Command Meaning

&C0

DCD is always on.

&C1

DCD follows the state of carrier from the remote system and turns on after the connect message.

&C2

DCD is on except momentarily at disconnect.

&C3¹

DCD goes active at the end of a modem handshake when the modem goes to data mode.

¹ &C3 must never be used without \D4 (see the "). For more information, see the "PoS Support" section.

&Dn (DTR Control)

Specifies the modem action when Data Terminal Ready (DTR) transitions off. The on-to-off transition of DTR must last as long as the value specified in register S25. Positive transitions of DTR (off-to-on) within five seconds after disconnect are ignored. Table 28 lists command options.

Default

&D3

Table 28: DTR Control Command Options
Command Meaning

&D0

Ignores DTR. DTR is not needed for autoanswer.

&D1

Enters command state on detecting on-to-off transition of DTR. DTR is not needed for autoanswer.

&D2

Sets the modem on-hook when detecting an on-to-off transition of DTR and prepares the serial port to accept an AT command at any speed. DTR is needed for autoanswer.

&D3

Sets the modem on-hook and resets when detecting an on-to-off transition of DTR and prepares the serial port to accept an AT command at any speed. DTR is needed for autoanswer.

&F (Restore Command Defaults )

Restores the factory default configuration. Stored telephone numbers are not cleared.

&Gn (Guard Tone)

Sets the guard tone frequency on the answering mode. Table 29 lists command options.

Default

&G0

Table 29: Guard Tone Command Options
Command Meaning

&G0

Disables the guard tone

&G1

Sets the guard tone on the answering modem to 550 Hz

&G2

Sets the guard tone on the answering modem to 1800 Hz

&Pn (Dial Pulse Ratio)

Sets the ratio of off-hook (make) to on-hook (break) time that the modem uses for pulse dialing. Table 30 lists command options.

Note Pulse dialing is not supported in Japan.

Default

&P0

Table 30: Dial Pulse Ratio Command Options
Command Meaning

&P0

Make 39 percent, break 61 percent

&P1

Make 33 percent, break 67 percent

&Sn (DSR Options)

Sets the serial port Data Set Ready (DSR) signal. Table 31 lists command options.

Default

&S0

Table 31: DSR Command Options
Command Meaning

&S0

DSR is always on. Equivalent to setting the Serial Port DSR/CTS command \D.

&S1

DSR is on with answer tone. Equivalent to setting the Serial Port DSR/CTS command \D3.

&Tn (Diagnostic Test Mode)

Configures the modem to run a local or remote diagnostic test. Use the &T0 command to stop a running diagnostic test.Table 32 lists command options.

Default

&T5

Table 32: Diagnostic Test Command Options
Command Meaning

&T0

Ends a test in progress. The test ends without terminating a connection, returning the local and remote modems to normal operation. If a self-test is in progress, &T0 reports any errors. This command must be the last command on a command line.

&T1

Runs a local analog loopback test. The modem should display characters on your screen exactly as you enter them. The modem must be in normal or direct mode and set to 1200 bps or higher.

&T3

Local digital loopback test. Allows a remote modem that does not support the CCITT V.54 standard to perform a remote digital loopback test with the modem. The modem must be in normal or direct mode and set to 1200 bps or higher.

&T4

Allows the modem to respond to a remote caller's request to enter remote digital loopback mode. The modem must be in normal or direct mode and set to 1200 bps or higher.

&T5

Prevents the modem from responding to a remote digital loopback request.

&T6

Instructs the remote modem to initiate a remote digital loopback test. The modem must be in normal or direct mode and set to 1200 bps or above.

&T7

Instructs the remote modem to enter a remote digital loopback with a self-test. After the test is complete, the remote modem reports errors to the local device. The modem must be in normal or direct mode and set to 1200 bps or above.

&T8

Runs a local analog loopback with a self-test. The modem sends itself the ITU-T V.54 test pattern, verifies characters to make sure they are received correctly, and reports errors to the local device. The modem must be in normal or direct mode and set to 1200 bps or above.

&W (Store Current Configuration)

Stores the current configuration. The &W command stores the active commands and S registers, except restricted S registers S2 to S12, and the serial port speed and parity and modem port speed in effect when you enter the command. Telephone numbers are stored independently with the \Pn and &Zn commands.

Note The &W command does not save registers S2 to S12; the AT*W command saves all registers.

Note The &W and *W commands share the same stored configuration area. Either of these commands overrides the other's stored settings. *W also stores settings for restricted S registers S2 to S12. If &W is used after *W, the default settings for the restricted S registers are restored. The stored settings are not saved during power up.

Parenthesis Command Set

This section describes modem commands that begin with a right-parenthesis ()) character.

)Mn (Power Level Adjustment for Cellular Telephone Connections)

Adjusts power levels during link negotiation for reliable connections to accommodate signaling requirements of cellular telephone equipment. Table 33 lists command options.

Default

)M0

Table 33: Power Level Command Options
Command Meaning

)M0

Adjusts the power level for central site modems if the remote modem is set to )M1. Use this option for MNP Class 10 modems that connect to both cellular and noncellular site modems.

)M1

Autoadjusts the power level for cellular modems.

Asterisk Command Set

This section describes modem commands that begin with an asterisk (*) character.

*I (Modem Identifier )

When the *I command is entered, the following prompt appears:

ID:

The identifier can consist of up to 25 ASCII characters. It is truncated after the 25th character. The modem identifier is also displayed by the \S command (Read Online Status).

Default

No default identifier.

*W (Store Complete Configuration)

Stores the complete modem configuration. The *W command stores the active commands and S registers, including the current values of restricted S registers S2 to S12 (which are not stored with &W), and the serial port speed and parity and modem port speed in effect when you enter the command. Telephone numbers are stored independently with the \Pn and &Zn commands.

Note The AT*W command saves all registers; the &W command does not save registers S2 to S12.

Note The &W and *W commands share the same stored configuration area. Use one of the commands to override the other stored settings. The &W command stores the default settings for the restricted S registers S2 to S12. If &W is used after a *W command, the default settings for the restricted S registers are stored. The stored settings are not saved during power up.

Hyphen Command Set

This section describes modem commands that begin with a hyphen (-) character.

-D{dial string} (Repeat Dial)

Redials a telephone number, up to nine times, until a connection is made. In reliable mode, the modem does not redial the number if the remote modem answers but fails to establish a reliable connection. Table 34 lists command options.

Note Repeat dialing is not supported in Japan.

The dial string contains up to 98 characters. Valid dial string characters are 0-9, the dial modifiers listed in Table 3, and the # and * characters for tone dial. The modem ignores invalid characters.

Table 34: Repeat Dial Command Options
Command Meaning

-D/n

n is an integer between 1 and 9 that specifies a telephone number stored with the \P command.

-DL

Redials the last number dialed.

-DS

Dials the first entry stored in the directory.

-En (Modem Port Data Length)

Specifies the number of data bits used on the modem port during normal mode connections when the \N0 command (Operating Mode) is set, and the serial port is configured for asynchronous transmission of 11-bit characters. Both modems must be set to the same number of data bits. Table 35 lists command options.

The modems cannot pass data when a \N3 or \N5 reliable connection is set and falls back to a normal connection with 11-bit data characters enabled on both modems.

Default

-E0

Table 35: Modem Port Data Length Command Options
Command Meaning

-E0

Enables 10-bit data during normal mode connections

-E1

Enables 11-bit data during normal mode connections

-Hn (Dumb Mode)

Configures the modem to smart mode (recognize commands on the Data Terminal Equipment [DTE] port and send result codes) or dumb mode (ignore commands on the DTE port and do not send result codes). Table 36 lists command options.

Default

-H0

Table 36: Dumb Mode Command Options
Command Meaning

-H0

Smart mode

-H1

Dumb mode

-In (Country Code)

Sets the country code for the modem. The code does not take effect until the modem has been reset by the Z (Reset) command or a power cycle. Table 37 lists country codes.

Country codes that are set manually (that is, not following the procedure described in the next section) remain in effect until one of the following events occurs:

Another -I command is sent.
The firmware is reloaded. (Firmware reloads always reset the country code to USA.)
The router is power cycled.
The router is reloaded.

Note You can also set country codes using the Cisco IOS modem country command. For more information, see the Cisco IOS configuration guides and command references. The modem country command takes effect immediately, but all active calls are dropped.

Changing Country Codes on Microcom Modems

This section describes how to change the country code for analog modem network modules. The default country code is USA. The USA country code is also used for the following countries: Argentina, Brazil, Canada, Chile, China, Columbia, Hong Kong, India, Indonesia, Korea, Malaysia, Mexico, Peru, Philippines, Singapore, Taiwan, and Thailand. If you are using the modems in a different country, you must change the country code. Some countries also require additional configuration.

Configure

Follow these steps:

Step 1 Enter global configuration mode:

Router> enable
Router# config term
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#

Step 2 Edit the new modemcap and specify the country code (-InZ) in the miscellaneous attributes field. Replace n with one of the country codes listed in the Country Code column of Table 37. In the following example, the country code is set to "18" for the Czech/Slovak Republic:

Router(config)# modemcap edit micro_czech miscellaneous -I18Z

Table 37: Country Codes
Country Country Code Country Code Displayed in Banner

Australia

20

49

Austria

22

92

Belgium¹

23

67

Czech/Slovak Republic¹

18

91

Denmark

10

63

Finland

9

71

France¹

25

32

Germany

17

68

Israel

15

16

Italy

3

21

Ireland

24

97

Japan

13

14

Netherlands

5

04

New Zealand

11

55

Norway

8

72

Poland

19

93

Portugal

27

94

Spain

6

76

South Africa

16

69

Sweden

7

09

Switzerland¹

14

66

UK²

2

12

USA³

1

85

¹The S-register is set to S0=2 (answer on the second ring) by default. Additional configuration is required.
²The UK country code is also used for Greece, Hungary, and Saudi Arabia.
³The USA country code also applies to Argentina, Brazil, Canada, Chile, China, Columbia, Hong Kong, India, Indonesia, Korea, Malaysia, Mexico, Peru, Philippines, Singapore, Taiwan, and Thailand.

Step 3 If you are using the country code for Belgium, the Czech/Slovak Republic, France, or Switzerland, additional configuration is required. These country codes are set by default to answer on the second ring (that is, the s-register is set to s0=2).

Edit the modemcap to answer calls on the second ring:

Router(config)# modemcap edit micro_czech autoanswer s0=2

Enter the :T26=8 command. Note that you must reenter the country code too. Whenever you modify an attribute field, you must enter all values. New values are not appended to existing values.

Router(config)# modemcap edit micro_czech miscellaneous :T26=8-I18Z
Router(config)# exit
Router#

Step 4 If you are using the modem in Malaysia, add the following modemcap miscellaneous entry:

Router(config)# modemcap edit micro_malaysia miscellaneous :T93=10:T94=8Z
Router(config)# exit
Router#

Step 5 Enter global configuration mode and specify the lines on which to apply the new modemcap. Lines 1 through 48 are specified in the following example:

Router# config term
Router(config)# line 1 48
Router(config-line)# modem autoconfigure type micro_czech

Messages appear while the modems are reconfigured using the new modemcap. When the last message appears, press Return:

.
.
.
3w5d: TTY48: Done with modem configuration

Step 6 Save the configuration changes to NVRAM:

Router(config-line)# Ctrl-Z
Router# copy running-config startup-config
[OK]

Verify

Verify the configuration changes using one of the following methods.

The following example shows verification from the router command prompt:

Router# show modemcap mcom_czech
Modemcap values for mcom_czech
Factory Defaults (FD):  [not set]
Autoanswer (AA):  [not set]
Carrier detect (CD):  [not set]
Drop with DTR (DTR):  [not set]
Hardware Flowcontrol (HFL):  [not set]
Lock DTE speed (SPD):  [not set]
DTE locking speed (DTE):  [not set]
Best Error Control (BER):  [not set]
Best Compression (BCP):  [not set]
No Error Control (NER):  [not set]
No Compression (NCP):  [not set]
No Echo (NEC):  [not set]
No Result Codes (NRS):  [not set]
Software Flowcontrol (SFL):  [not set]
Caller ID (CID):  [not set]
On-hook (ONH):  [not set]
Off-hook (OFH):  [not set]
Miscellaneous (MSC):  -i18z		
Template entry (TPL):  [not set]
Router#

Note The Miscellaneous (MSC) field is the only nondefault field set in the modemcap.

The following example shows verification using debug:

Step 1 Enable modem debug:

Router# debug confmodem
Modem Configuration Database debugging is on
Router# debug modem
Modem control/process activation debugging is on
Router#

Step 2 Clear an idle line:

Router# clear line 1
[Confirm]
OK

DTR drops and modem autoconfigure runs when the modem is reset. It may take a minute while the messages appear:

Router#
*Mar  3 23:20:26.114: TTY1: Line reset
*Mar  3 23:20:26.118: TTY1: Modem: IDLE->HANGUP
*Mar  3 23:20:26.534: TTY1: dropping DTR, hanging up
*Mar  3 23:20:26.534: tty1: Modem: HANGUP->IDLE
*Mar  3 23:20:31.838: TTY1: restoring DTR
*Mar  3 23:20:32.958: TTY1: Modem command:  --AT&F&C1&D2:T26=8-I18Z
\ Q3\N5-K0\J0%C3$B115200S0=2H0--
*Mar  3 23:20:34.234: TTY1: Modem configuration succeeded
*Mar  3 23:20:36.090: TTY1: locking speed (115200) response ---OK---
*Mar  3 23:20:36.090: TTY1: locked DTE speed at 115200
*Mar  3 23:20:36.094: TTY1: Done with modem configuration

Step 3 Verify that the country code has changed, entering the IP address of your LAN interface, and port 2000 + n, where n is the modem line number:

Router# telnet 172.16.10.1 2001
You are now entering AT command mode on modem (slot 0 / port 0).
at%v1 
 
MNP Class 10 V.34 Modem Rev x.x.x/91
 
OK

Locate "91" in the "Country Code Displayed in Banner" column of Table 2. Note that it identifies the Czech/Slovak Republic.

Step 4 Enter the disconnect command to exit the modem session:

Router# disconnect line 1
Router#

-Jn (Detect Phase)

Configures the originating modem to send a control sequence to the answering modem to determine the type of error correction enabled, either LAPM, MNP, or none. See the \Nn command (Operating Mode) for information about the types of connections that can be established. Table 38 lists command options.

Default

-J1

Table 38: Detect Phase Command Options
Command Meaning

-J0

Disables detect phase

-J1

Enables detect phase

-Kn (MNP Extended Services)

Configures the modem to use MNP extended services that are not available when operating in LAPM mode. For example, two modems with MNP extended services enabled negotiate MNP Class 10 with V.42 bis compression instead of LAPM. Table 39 lists command options.

Default

-K1

Table 39: MNP Extended Services Command Options
Command Meaning

-K0

Disables MNP extended services

-K1

Enables MNP extended services

-K2

Enables MNP extended services without MNP indication during the answer detect phase

-Mn (MNP Class Connect Messages)

Determines whether MNP class connect messages are displayed. Table 40 lists command options.

The -M1 setting overrides the \V command (Error Correction Result Code Form) for long-form connection result codes and the Wn command (Connection Speed Reporting) for serial-port connect messages. The following commands override the -Mn command:

V0 (short form result codes enabled)
X0 (extended result codes disabled) displays only CONNECT

Default

-M0

Table 40: MNP Connect Messages Command Options
Command Meaning

-M0

Disables MNP class connect messages

-M1

Enables the following formats for MNP class connect messages, where n equals MNP class (from 1 to 10), and x means the type of data compression (V.42 bis or MNP Class 5):

CONNECT for normal and direct connections

CONNECT MNPn/x for MNP connections

CONNECT MNPn for modems that do not negotiate compression

CONNECT MNPn/CELLULAR/x if )M1 (Power Level Adjustment) is set

CONNECT LAPM for LAPM connections with no compression active

CONNECT LAPM/V42 bis for LAPM V.42 bis connections

-On (Serial Port Parity)

Changes the serial port parity set by the AT sequence. Use this command when the local device supports XON/XOFF flow control and detects parity to ensure that all modem-generated XON and XOFF characters have the correct parity. Table 41 lists command options.

You can also use the -On command to change the serial port parity while connected to a remote device. Modem port parity cannot be changed after a connection is established. When the parity required for a connection is not the parity set by the sequence, you must set the correct parity when you enter the Dial command, as part of the same command line.

The AT sequence cannot be used to match space parity; no parity is set instead. You must enter -O3 to set space parity.

Default

-O4

Table 41: Serial Port Parity Command Options
Command Meaning

-O0

7 data bits, odd parity

-O1

7 data bits, even parity

-O2

7 data bits, mark parity

-O3

7 data bits, space parity

-O4

8 data bits, no parity

-O5

8 data bits, odd parity

-O6

8 data bits, even parity

-O7

8 data bits, mark parity

-Pn (Check Parity)

Controls parity checking of XON and XOFF characters, the escape code sequence, and HP ACK characters. In command state, all command echoes and command responses from the modem are sent to the workstation with parity that matches the serial port parity. Table 42 lists command options.

Default

-P1 (Japan)

-P0 (elsewhere)

Table 42: Check Parity Command Options
Command Meaning

-P0

Ignores parity for special characters. All received data is passed to the workstation with parity corrected to match the serial port parity.

-P1

Processes special characters received from the workstation only if their parity matches the serial port parity. All received data is passed to the workstation at 8 data bits with no parity.

-P2

Processes special characters only if their parity matches the serial port parity. Modem port flow control characters are recognized, regardless of whether their parity matches the serial port parity. All received data is passed to the workstation with parity corrected to match the serial port parity.

-Qn (Fallback Modulation Speed)

Configures the modem to fall back from a V.32 bis or V.32 MNP reliable connection at 14400, 9600, 7200, or 4800 bps to a V.22 bis MNP reliable connection at 2400 bps or a V.22 MNP reliable connection at 1200 bps. Fallback can occur when poor telephone lines cause excessive MNP retransmissions. Table 43 lists command options.

Fallback from a V.32 bis or V.32 MNP reliable connection to V.32 bis or V.32 at 4800 bps is always enabled for any -Qn command option. The modem always uses the V.22 standard when it falls back from a V.32 MNP reliable connection to a 1200 bps MNP reliable connection for any Bn setting (ITI-U/Bell mode).

Default

-Q2

Table 43: Modulation Speed Command Options
Command Meaning

-Q0

Disables fallback from a V.32 bis or V.32 MNP reliable connection to an MNP reliable 2400 or 1200 bps connection

-Q1

Enables fallback from a V.32 bis or V.32 MNP reliable connection to an MNP reliable 2400 bps connection

-Q2

Enables fallback from a V.32 bis or V.32 MNP reliable connection to an MNP reliable 2400 or 1200 bps connection

-V (Split Modem Port Speed with Multiprotocol Autoanswer)

Determines whether the modem port uses split transmit and receive speed operation when using the multiprotocol autoanswer feature. %F0 must also be set. Note that V.23 is the split speed on the modem link (that is, 75/1200 bps).

Default

-V1 for U.S.
-V0 for international

Table 44: Split Serial Port Speed with Multiprotocol Autoanswer Command Options
Command Meaning

-V0

Enables V.23 split modem port speed connections within the multiprotocol autoanswer feature

-V1

Disables V.23 split modem port speed connections within the multiprotocol autoanswer feature

Colon Command Set

This section describes modem commands that begin with a colon (:) character.

:Dn (Manual Dial)

Sets the modem off-hook in originate mode when DTR is raised. Table 45 lists command options.

Default

:D0

Table 45: Manual Dial Command Options
Command Meaning

:D0

The modem is not set off-hook when DTR is raised.

:D1

The modem is set off-hook in originate mode when DTR is raised. &Dn (DTR Control) also must be set. For example, if &D2 is set, the modem is set off-hook 5 seconds after recognizing the positive transition of DTR.

:D2

The modem is set off-hook in originate mode and dials the first stored telephone number when DTR is raised. &Dn must also be set.

:En (Compromise Equalizer)

Configures the modem to use the compromise equalizer when it connects in V.32 mode. Table 46 lists command options.

Default

:E1

Table 46: Compromise Equalizer Command Options
Command Meaning

:E0

Disables the compromise equalizer only when the modem is in V.32 mode. Use :E0 only when you are performing back-to-back or PBX-to-PBX V.32 mode connections.

:E1

Enables the compromise equalizer. Use :E1 for outside-line-to-outside-line or PBX-to-outside-line connections.

:Tn? (Read Configuration Register)

Displays the contents of :T register n (where n is a decimal number).

@ Character Command Set

This section describes modem commands that begin with an at (@) character.

@Cn (CTR, DSR, and DCD Connect Message Control)

Sets DSR, Clear To Send (CTS), and DCD on before or after a connect message. Used with the :T14 (Connect Message Delay Timer) register. Table 47 lists command options.

Default

@C0

Table 47: Connect Message Control Command Options
Command Meaning

@C0

Sets CTS, DSR, and DCD on before the connect message is sent

@C1

Sets CTS, DSR, and DCD on after the connect message is sent

@E (Detailed Modem Call Status)

This is an unofficially supported modem status and debugging command that can be used by an experienced user to verify the detailed status of the modem during or after a call. The content of this command may change as required to assist in problem resolution. Therefore, the command may produce results that differ from the description in this document. For more information, see the "Debugging" section.

@Mn (Select Transmit Level for Cellular Connections)

Selects the initial transmit level for the connection. You can set levels from -10 to -35 decibels referred to 1 milliwatt (dBm). From @M10 to @M35, the level is the as -n dBm. Table 48 lists selected transmit level command options.

Default

@M0

Table 48: Selected Transmit Level Command Options
Command Meaning

@M0

-26 dBm

@M1

-30 dBm

@M2

-10 dBm

@M10

-10 dBm

@M35

-35 dBm

@Un (Minimum Connection Speed)

Selects the minimum speed for the connection. You can set the speed n for 300, 600, 1200, 2400, 4800, 7200, 9600, 12000, 14400, 16800, 19200, 21600, 24000, 26400, or 28800 bps.

Backslash Command Set

This section describes modem commands that begin with a backslash (\) character.

\An (Maximum MNP Block Size)

Sets the maximum block size for MNP stream link connections. Table 49 lists command options.

Default

\A3

Table 49: MNP Block Size Command Options
Command Meaning

\A0

64 characters

\A1

128 characters

\A2

192 characters

\A3

256 characters

\Bn (Transmit Break)

Sends Break to the remote system for 100n milliseconds. In a reliable link, Break is always sent for 300 milliseconds. Use the O command (Enter Connect State) to return to connect state. See also the \K command (Break Control).

Range

1 to 9 (100-millisecond increments)

Default

\B3 (300 milliseconds)

\Cn (Autoreliable Buffer)

Configures the modem to buffer data in autoreliable, autoanswer mode. The answering modem's data buffer can be used to store data during the 3-second link negotiation for a reliable connection. Table 50 lists command options.

For example, you can use %A to set the autoreliable fallback character to ASCII 13 (carriage return). Then set \C2 and \N3 (autoreliable mode). Non-MNP callers who connect and press Return to log on do not need to wait for the 3-second autoreliable window to expire before data can pass. See the \Nn command (Operating Mode) for more information about autoreliable and normal modes.

The \Jn command (Bps Rate Adjust) affects the type of connection established. Reliable and direct connections can result when bps rate adjust is enabled (\J1). Reliable and normal connections may result when bps rate adjust is disabled (\J0).

Default

\C0

Note When either \C1 or \C2 is set, reliable and normal connections can result regardless of bps rate adjustments.

Table 50: Autoreliable Buffer Command Options
Command Meaning

\C0

Data is not buffered during link negotiation. The modem changes to normal or direct mode if a SYN character is not detected within 3 seconds.

\C1

Buffers all data on the answering modem until 200 non-SYN characters are received or a SYN character is detected within 3 seconds.

If 200 non-SYN characters are received, the modem changes to normal mode and passes the data to the serial port. If the modem detects a SYN character within 3 seconds, it attempts to establish a reliable connection. Otherwise, the modem changes to normal mode.

\C2

Data is not buffered on the answering modem. The modem changes to normal mode when it receives an autoreliable fallback character defined by the %A command and passes that character to the serial port. Use the%C2 command when the modem receives calls from both modems that support MNP and modems that do not support MNP, so that the modem can change to normal mode as soon as it detects a logon character (defined by %A) from a non-MNP caller, eliminating the 3-second wait.

\Dn (Serial Port DSR/CTS Control)

Controls the DSR and CTS signals on the serial port. Use this command when the central site computer requires DSR and CTS to be off at certain times. Table 51 lists command options.

Selecting hardware flow control for the serial port overrides the \Dn command. When hardware flow control is selected, the CTS line indicates the ability of the modem to receive data from your workstation, and the DSR action does not change.

Default

\D0

Table 51: Serial Port DSR/CTS Control Command Options
Command Meaning

\D0

DSR and CTS are always on.

\D1

DSR and CTS follow DCD. If the &C1 command (Serial Port DCD Control) is also set, DSR follows off-hook.

\D2

DSR and CTS both follow DCD.

\D3

DSR follows the answer tone, CTS is always on.

\D4¹

CTS is held low during modem training after DCD is asserted.

¹ &C3 is never used without \D4 (see the "). For more information, see the "PoS Support" section.

Serial Port Signal Options

Use the &Cn and \Dn commands to control the serial port DCD, DSR, and CTS signal levels when your workstation requires DCD, DSR, and CTS to be off at certain times. Table 52 lists command options and signal level results.

Table 52: Serial Port Signal Options
&Cn Option \Dn Option Result

0

0

DCD on, DSR on, CTS on

0

1

DCD on, DSR on, CTS on

0

2

DCD on, DSR on, CTS on

0

3

DCD on, DSR with answer tone, CTS on

0

4

DCD on, CTS and DTR comply with ITU-T recommendations

1

0

DCD follows modem carrier, DSR on, CTS on

1

1

DCD follows modem carrier, DSR follows off-hook, CTS follows CD

1

2

DCD follows modem carrier, DSR and CTS both follow CD setting

1

3

DCD follows modem carrier, DSR with the answer tone, CTS on

1

4

DCD follows modem carrier, CTS and DTR comply with ITU-T recommendations

2

0

DCD on (off for a few seconds at disconnect only), DSR on, CTS on

2

1

DCD, DSR, and CTS on (off for a few seconds at disconnect)

2

2

DCD, DSR, and CTS on (off for a few seconds at disconnect)

2

3

DCD off at disconnect then on, DSR with the answer tone, CTS on

2

4

DCD on (off for a few seconds at disconnect only), CTS and DTR comply with ITU-T recommendations

\En (Data Echo)

Configures the modem to echo characters sent from the local workstation in connect state. Table 53 lists command options.

Default

\E0

Table 53: Data Echo Command Options
Command Meaning

\E0

Does not echo data sent by the local workstation.

\E1

Echoes data sent by the local workstation. \E1 functions only with normal mode connections.

\F (Display Stored Phone Numbers )

Displays the telephone numbers currently stored in the telephone directory.

\Gn (Modem Port Flow Control)

Sets the flow control method used to pace data between modems during a normal mode connection. Table 54 lists command options.

A reliable link has its own method of flow control and ignores the \Gn setting. The \ Qn command (Serial Port Flow Control) settings determine DTE port flow control during a reliable link.

Default

\G0

Table 54: Modem Port Flow Control Command Options
Command Meaning

\G0

Disables modem port flow control.

\G1

Sets modem port flow control to XON/XOFF. The modem sends an XOFF character to stop received data and sends an XON character to resume reception of data.

\G2

Sets modem port flow control to unidirectional XON/XOFF. The modem sends XON and XOFF characters to the remote device but ignores XON and XOFF received from the remote device.

\Jn (BPS Rate Adjust)

Automatically adjusts the speed of the serial port to match the speed of the connection. Table 55 lists command options.

When a reliable connection is established at a speed between 4800 and 14400 bps and the bps rate adjust option is enabled, the serial port speed always adjusts to 9600 bps. If the connection is established at 14400 bps or higher, the serial port speed is adjusted to 19200 bps. If you set the serial port to the modem's highest rate of 115200 bps, turn off bps rate adjust so the serial port stays at 115200 bps.

Default

\J0

Note When \J1, \C0 (the autoreliable buffer), and \N3 (the autoreliable mode) are set, the modem uses direct mode instead of normal mode if a reliable connection is not established.

Table 55: BPS Rate Adjust Command Options
Command Meaning

\J0

Disables bps rate adjust. The serial port rate is independent of the rate of the connection. This option is recommended for the highest throughput when data compression is used.

\J1

Enables bps rate adjust. The modem automatically adjusts the speed of the serial port to match the speed of the connection until the connection terminates. If your workstation does not automatically change to the adjusted bps rate, you must manually change the bps rate to the new setting. See the %U command (Clear Serial Port Speed) for information about resetting the serial port bps rate.

\Kn (Break Control)

Determines the type of Break the modem transmits when it receives a Break. Table 56 describes the effect of n. The modem can buffer up to four Breaks on both the modem port and the serial port.

Default

\K5

Note In reliable link connect state, the sender's Break control setting determines how the receiver handles the Break.

Table 56: Break Control Command Options
Command Local DTE Sends Break During Reliable or Normal Connection Local DTE Sends \Bn, Local Modem in Command Mode, During Reliable or Normal Connection Local Modem Sends Break During Direct Connection Remote Modem Sends Break During Normal Connection

\K0

Enter command state; no Break to the remote system¹

Empty data buffers; send a Break to the remote system

Send a Break to the remote system; set the modem to command state

Empty data buffers; send a Break to the serial port

\K1

Empty data buffers; send a Break to the remote system

Same as \K0

Send a Break to the remote system

Same as \K0

\K2

Same as \K0

Immediately send a Break to the remote system

Same as \K0

Immediately send a Break to the serial port

\K3

Immediately send a Break to the remote system

Same as \K2

Same as \K1

Same as \K2

\K4

Same as \K0

Send a Break to the remote system in sequence with any transmit data being buffered

Same as \K0

Send a Break to the serial port in sequence with the receive data being buffered

\K5

Send a Break to the remote system in sequence with transmit data

Same as \K4

Same as \K1

Same as \K4

¹Forces the modem to command state. To transmit a Break and enter connect state, enter the \B0 command. See the \B command description for details.)

\Nn (Operating Mode)

Selects the modem operating mode. Table 57 lists command options.

Default

\N3

Note You can set the operating mode for a single call using dial modifiers. See Table 3 for details.

Table 57: Operating Mode Command Options
Command Meaning

\N0

Sets normal mode. \N0 can be used to communicate with most modems. No error correction is performed in normal mode.

\N1

Sets direct mode. \N1 ignores flow control and does not buffer data. In connect state, the serial port always adjusts to the speed of the connection for any \Jn setting. No error correction is performed in direct mode. The escape code sequence is disabled in direct mode if \J0 is set.

\N2

Sets MNP reliable mode to provide error detection and automatic data retransmission between systems that support the MNP reliable link. The modem disconnects if it fails to establish an MNP reliable link immediately after making a connection. Some protocols are not timed to work with MNP and can interfere with its effectiveness.

Both modems should use flow control on the serial port in an MNP reliable link. When a transmission error is detected, data is buffered during the retransmission.

\N3

Sets autoreliable mode. The answering modem looks for incoming MNP or LAPM protocol characters from the remote modem. If it detects the characters within approximately 3 seconds, it tries to establish a reliable link connection. If both modems are set to autoreliable mode, a normal connection or no connection can result because of noise on the telephone line.

When the modem is set to autoanswer in autoreliable mode, you can shorten the 3-second period by using the %A command with the \C2 command.

\N3 lets the modem communicate with remote modems that may not support the MNP or LAPM reliable link.

\N4

Sets LAPM reliable mode to provide error detection and automatic data retransmission between systems that support the LAPM reliable link. The modem disconnects if it fails to establish a LAPM reliable link immediately after making a connection.

\N5

Sets LAPM reliable mode with fallback to normal mode.

\N6

Sets LAPM reliable mode with fallback to MNP reliable mode.

Table 58 lists connections that can be established, depending on the operating mode enabled on each modem. When more than one operating mode is listed within a column, the first mode is for the originating modem and the second is for the answering modem. NC indicates no connection.

Note For LAPM connections listed in Table 58, if the originate and answer modems have -K1 (MNP Extended Services) set for V.42 connections, the extended features of MNP are applied during the connection.

Table 58: Possible Connections for Operating Mode Command Options
Answering Modem Originating
Modem

\N0

\N1

\N2

\N3

\N4

\N5

\N6

\N0

Normal

Direct/normal

NC

Normal

NC

Normal

NC

\N1

Normal/direct

Direct

NC

Normal/direct

NC

Normal/direct

NC

\N2

NC

NC

MNP

MNP

NC

NC

MNP

\N3

Normal

Direct/normal

MNP

MNP

LAPM

LAPM

LAPM

\N4

NC

NC

NC

LAPM

LAPM

LAPM

LAPM

\N5

Normal

Direct/normal

NC

LAPM¹

LAPM

LAPM

LAPM

\N6

NC

NC

MNP

MNP

LAPM

LAPM

LAPM

¹For the modem to establish a LAPM connection, -K0 must be set.

\Pn{dial string} (Store a Telephone Number)

Stores entry n in the modem's telephone directory, where n is an integer (1 to 9) and dial string is a string of up to 98 characters. Valid dial string characters are 0 to 9, dial modifiers, and # and * for tone dialing. The modem ignores invalid characters. Dial strings longer than 98 characters return error messages. Phone numbers are not saved during a power reset.

\ Qn (Serial Port Flow Control)

Selects the flow control method used in the serial port. In direct mode connections, the modem ignores the \ Qn command. Table 59 lists command options.

Default

\ Q3

Table 59: Serial Port Flow Control Command Options
Command Meaning

\ Q0

Disables flow control.

\ Q1

Enables bidirectional XON/XOFF flow control. Data transmission is stopped by an XOFF character and restarted by an XON character. The modem generates XON and XOFF characters at the same parity used on the serial port. The serial port responds to XON and XOFF characters sent by the local workstation in the same way.

\ Q2

Enables unidirectional CTS/RTS hardware flow control. The modem turns CTS off to signal the local workstation to stop transmitting data and turns CTS on to signal the local workstation to resume transmitting data.

\ Q3

Enables bidirectional CTS/RTS hardware flow control. The modem uses CTS to start and stop transmission from the local workstation. When RTS is off, the modem stops transmitting. When RTS is on the modem resumes transmission.

\ Q4

Enables unidirectional XON/XOFF flow control. The modem serial port generates, but does not respond to, XON/XOFF flow control characters. This setting allows for computers to transmit data that contains XON and XOFF data characters. The computer can still be set to respond to XON/XOFF flow control characters sent to it from the modem during serial port flow control.

\ Q5

Enables unidirectional hardware flow control and keeps CTS off until the connection is established.

\ Q6

Enables bidirectional hardware flow control and keeps CTS off until a connection is established. RTS is ignored when it is not connected.

\Rn (Serial Port Ring Indicator)

Controls the Ring Indicator (RI) signal. RI follows the incoming ring signal on the telephone line. Table 60 lists command options.

Default

\R1

Table 60: Serial Port Ring Indicator Command Options
Command Meaning

\R0

Turns on the ring indicator signal after the ring and keeps it on for the duration of the telephone call.

\R1

Turns off the ring indicator signal after the telephone call is answered.

\Sn (Read Online Status)

Displays a list of modem commands and their current settings, the active connection type, the elapsed connect time, and the telephone number most recently dialed. The \S0 command outputs a single-screen display ( press any key for the next screen). The \S1 command outputs a continuous screen display. Press Ctrl-X or Break to cancel the display.

The following display is an example of \S1 command output with factory default settings:
 
at\s1
 
IDLE           000:02:01
LAST DIAL      t1714756,0947
 
NET ADDR:      FFFFFFFFFFFF
MODEM HW: OEM 2W United States
4 RTS 5 CTS 6 DSR - CD 20 DTR - RI 
MODULATION     IDLE
MODEM BPS      33600  AT%G0   
MODEM FLOW     OFF    AT\G0
MODEM MODE     AUT    AT\N3
V.23 OPR.      OFF    AT%F0
AUTO ANS.      ON     ATS0=1
SERIAL BPS     115200 AT%U1   
BPS ADJUST     OFF    AT\J0
SPT BPS ADJ.   0      AT\W0
ANSWER MESSGS  OFF    ATQ2   
SERIAL FLOW    BHW    AT\Q3
PASS XON/XOFF  OFF    AT\X0
PARITY         8N     AT
BREAK          5      AT\K5
EXIT CHAR      043    ATS2=43
ANS DUMB MODE  ON     AT#E1
CMD ECHO       ON     ATE1
RESULTS        OFF    ATQ2
RESULT TYPE    MNPX   ATV1\V2
CONNECT MSG    MDM    ATW2
CONN MNP-      0      AT-M0
SPEED MATCH    1      AT%L1
EQUALIZER      1      AT:E1
FALLBACK       2      AT-Q2
DATA ECHO      OFF    AT\E0
INACT TIMER    00     AT\T0
AUTO RETRAIN   ON     AT%E1
COMPRESSION    ALL    AT%C3
MAX BLK SIZE   256    AT\A3
AUTO BUFF      0      AT\C0
AUTO CHAR      000    AT%A0
EMULATING HP   OFF    AT\H0
PAUSE TIME     002    ATS8=2
DTR            3      AT&D3
MABP ADDRESS   001    AT^P1
CARR DET       1      AT&C1
DSR            0      AT\D0
RING IND       1      AT\R1
SPKR CTRL      1      ATM1
SPKR VOL       2      ATL2
LNG SPC DISC   OFF    ATY0
DISC DELAY     000    AT%D0
RDLB ENABLE    OFF    AT&T5
DIAL MODE      4      ATX4   
PULSE DIAL     60%    AT&P0
PULSE MODE     N      AT%W0
V23 HD EQU     ON     AT%O1
GUARD TONE     0      AT&G0
DATA CALL TONE OFF    AT-C0
2ND FC         OFF    AT-F0
NM BIT VALUE   0      AT-E0
PAR CHK        0      AT-P0
MANUAL DIAL    0      AT:D0
UPSHIFT BPS    OFF    AT*H0
CELLULAR       OFF    AT)M0
LINETYPE       000    AT@M0
DETECT PHASE   ON     AT-J1
MNP EXT SVC    1      AT-K1
UNIV V.23      1      AT-V1
CONNECT MSG    1ST    AT@C0
DUMB MODE      OFF    AT-H0
BELL           ON     ATB1
CALL ABT DISAB OFF    AT-Y0
REVERSE ANS    OFF    AT-W0
MIN CONN SPD   300    AT@U
 
OK

Note The 00B MABP port address is a variable from 1-24.

\Tn (Inactivity Timer)

Specifies the time, in minutes, that the modem waits before hanging up when data is not sent or received. The inactivity timer is available only during normal and reliable link connections. \T0 disables the timer.

Range

0 to 90 minutes

Default

\T0 (disabled)

\Vn (Error Correction Result Code Form)

Sets the result code format to display a reliable link connection. The speed field content is determined by the Wn command (Connection Speed Reporting) setting. Setting -M1 (MNP Class Connect Messages) changes the format of the long form connection result codes. Table 61 lists command options.

Set V0\V3 if your software requires Hayes-compatible connection result codes. When V1 is set to select long form result codes, \V3 is equivalent to \V2.

Default

\V2

Table 61: Error Correction Result Code Command Options
Command Meaning

\V0

Displays standard long form result codes, CONNECT speed. Use \V0 when your communications software does not expect a reliable link result code, even if a reliable connection is established.

\V1

Adds /REL to long form error correction result codes, CONNECT speed /REL. 9600/REL also indicates 4800-, 7200-, and 12000-bps reliable connections.

\V2

Displays long form error correction protocol result codes:

CONNECT speed /REL-MNP

CONNECT speed/REL-LAPM

CONNECT speed/REL-CELLULAR

9600/REL also indicates 4800-, 7200-, and 12000-bps reliable connections.

\V3

Adds /REL to long form error correction result codes, CONNECT speed /REL Displays Hayes-compatible short form result codes. The result code displays the actual modem bps rate.

\V4

Enables long form error correction result codes:

CONNECT speed /REL-MNP

CONNECT speed/REL-LAPM

CONNECT speed/REL-CELLULAR

The result code displays the actual modem bps rate.

\V5

Enables reporting of the modulation type:

CONNECT speed/modulation/REL-MNP

CONNECT speed/modulation/REL-LAPM

CONNECT speed/modulation/REL-CELLULAR

Connection Result Code Tables

Analog modem network modules can display these result codes when they attempt to establish connection. The tables use the abbreviations: rel (reliable) and non-rel (non reliable).

Table 62 through Table 65 show the short and long form result codes, excluding connection result codes whose form depends on the \V, W, and -M commands.

Table 62: Result Codes
Short Form Long Form

0

OK

1

CONNECT

2

RING

3

NO CARRIER

4

ERROR

6 ¹

NO DIALTONE

¹Display of these call progress monitoring result codes depends on the setting of the X command.

Table 63: Long Form Connect Result Codes (DTE)
ATV1 - M0W0 or ATV1 M0W1
Report DTE speed

DTE Speed non-rel \V rel \V1 rel, \V rel¹ \V3 rel, \V4 rel¹, \V5 rel²

75

75

75 /REL

300

300

300 /REL

600

600

300 /REL

1200

1200

1200 /REL

2400

2400

2400 /REL

4800

4800

4800 /REL

9600

9600

9600 /REL

19,200

19200

19200 /REL

38,400

38400

38400 /REL

57,600

57600

57600 /REL

115,200

115200

115200 /REL

230,400

230400

230400 /REL

¹ If \V2 or \V4 are set and a reliable link is established, the message is displayed in one of the following formats:
CONNECT <speed>/REL - MNP or
CONNECT <speed>/REL - LAPM or
CONNECT <speed>/REL - CELLULAR or
CONNECT <speed>/REL- CELLULAR EC or
CONNECT <speed> /LAPM - CELLULAR EC
² In non-reliable V.21 or Bell 103 connections, the message is displayed as CONNECT.

Table 64: Short Form (Numeric) Connect Result Codes (DTE Speed)
ATV0W0 or ATV0W1 Report DTE speed

DTE Speed \V0
\V1 non-rel
\V2 non-rel
\V4 non-rel
\V5 non-rel
\V1 rel
\V2 rel
\V4 rel
\V5 rel

\V3

75

1

20

1

300

1

20

1

600

9

21

5

1200

5

22

5

2400

10

23

10

4800

30

31

11

9600

32

33

12

19200

36

37

14

38400

38

39

28

57600

42

43

29

115200

46

47

30

230400

48

49

51

Table 65: Short Form (Numeric) Connect Result Codes (Modulation)
ATV0W2 Report Modulation Speed

Modulation

Speed \V0 \V1 non-rel \V2 non-rel \V4 non-rel \V5 non-rel

\V1 rel \V2 rel

\V3

\V4 rel \V5 rel

Non-compression

V.21 or Bell 103

300

1

20

1

20

79

V.23 half-duplex

1200

5

5

24

V.23 split speed

75/1200

11

23

24

V.22

600

9

21

5

21

21

V.22 or Bell 212A

1200

5

22

5

22

80

V.34/V.22bis

2400

10

23

10

23

81

V.34/V.32

4800

30

31

11

31

82

V.34/V.32bis

7200

40¹

33

24

41

83

V.34/V.32

9600

32

33

12

33

84

V.34/V.32bis

12000

44¹

33

25

45

85

V.34/V.32bis

14400

34¹

35

13

35

87

V.34

16800

60

61

13

61

88

V.34

19200

36

37

14

37

89

V.34

21600

62

63

13

63

90

V.34

24000

64

65

13

65

91

V.34

26400

66

67

13

67

92

V.34

28800

68

69

13

69

93

V.34

31200

70

71

13

94

94

V.34

33600

72

73

13

95

95

¹ When \V0 is set, the following numeric codes are displayed: 14400 bps=34; 12000 bps=44; 7200 bps=40.

\Wn (Split Serial Port Speed)

Determines whether the serial port uses split transmit and receive speed operation when %F1 or %F2 is set to select V.23 mode. Table 66 lists command options.

Default

\W0

Table 66: Split Serial Port Speed Command Options
Command Meaning

\W0

Disables split serial port speed

\W1

Enables split serial port speed

\Xn (XON/XOFF Passthrough)

Determines whether XON/XOFF flow control characters are sent to the remote or local modem. When XON/XOFF flow control is enabled on the serial port (\ Q1) and XON/XOFF passthrough is enabled (\X1), the modem transmits any XON and XOFF characters sent to the serial port from the local device to the remote device. Table 67 lists command options.

Default

\X0

Caution With \X0 (XON/XOFF passthrough) set and XON/XOFF flow control enabled, local devices such as printers can send XON and XOFF characters to the modem serial port. If the modem is controlling the flow of data to the remote system, these local flow control characters do not interfere with the connection. However, if \X1 is set, the local flow control characters also pass through to the remote system. These characters can turn on the flow of data from the remote system before the modem is ready to receive it, resulting in loss of data.

Table 67: XON/XOFF Passthrough Command Options
Command Meaning

\X0

Processes XON/XOFF flow control characters

\X1

Processes XON/XOFF flow control characters and passes them to the local or remote system

# Character Command Set

This section describes modem command that begins with a # character.

#En (Answer Mode Escape Sequence)

Determines detection of the escape sequence (+++) when the modem is in answer mode.

Default

#E1

Table 68: #E Command Options
Command Meaning

#E0

Enables the escape code sequence in answer mode.

#E1

Disables the escape code sequence in answer mode.

Modem S and :T Register Summary

The modem saves configuration settings in S and :T registers similar to Hayes Smartmodem 2400 registers. Each register controls a single modem function or is bit-mapped to control several functions. This section describes commands to display and change register values. We recommend that, wherever possible, you use the following commands only to display register contents and use the AT command set to change register values.

Read All Registers

The %Rn command displays the contents of an entire register set. The register set contents are displayed as a table in decimal and hexadecimal format.

%R0 displays the contents of all S registers.

%R1 displays the contents of all :T registers.

Point to a New Reference Register

The Sn and :Tn commands set the modem register pointer to register n. Register n then becomes the reference register for following register commands.

ATSn sets the modem register pointer to S register n.

AT:Tn sets the modem register pointer to :T register n.

Read a Configuration Register

The Sn? and :Tn? commands display the contents of register n, in decimal format only. Register n becomes the reference register.

ATSn? displays the contents of S register n.

AT:Tn? displays the contents of :T register n.

Change the Value of a Register

The Sn=x and :Tn=x commands change the value of register n to x. Register n becomes the reference register.

ATSn=x changes the value of S register n to x.

AT:Tn=x changes the value of :T register n to x.

Display the Value of the Reference Register

The AT? command displays the value of the last S register referenced in a read, write, or pointer command.

Change the Value of the Reference Register

The AT=x command changes the value of the last S register referenced to x..

S Register Descriptions

This section describes the purpose and format of each S register.

S0 (Ring to autoanswer On )

Register S0 specifies the number of rings before the modem answers. Set register S0 to zero to disable autoanswer. Ring signals are ignored for 5 seconds after disconnect.

Range

0 to 255 rings

Default

1 ring

S1 (Ring Counter )

Counts the rings before the modem answers a call. If there is no ring within eight seconds of the last ring, S1 is reset to zero. Ring signals are ignored for five seconds after disconnect.

S2 (Escape Code Character )

Specifies the character used for the three-character escape code sequence. When the modem is in connect state and receives the escape code sequence, it enters command state. Setting register S2 to zero disables the escape code character. Register S12 sets the guard time that must be present before and after the escape code character.

Range

0 to 255 (ASCII decimal)

Default

43 (+)

S3 (Carriage Return Character )

Specifies the carriage return (CR) character. The carriage return terminates command lines and result codes.

Range

0 to 127 (ASCII decimal)

Default

13 (Carriage Return)

S4 (Line Feed Character)

Specifies the line feed (LF) character. The line feed character follows a carriage return at the end of command lines and result codes.

Range

0 to 127 (ASCII decimal)

Default

10 (Line feed)

S5 (Backspace Character )

Specifies the backspace (BS) character.

Range

0 to 32 (ASCII decimal)

Default

8 (Backspace)

S6 (Wait Before Dialing )

Specifies the time the modem waits after transitioning off-hook before dialing. This is a minimum of two seconds, even if register S6 is set to a value less than 2. Register S6 is used only when the X0, X1, or X3 command (Extended Result Code) is set.

Range

3 to 255 seconds (Japan)
2 to 255 seconds (elsewhere)

Default

3 seconds (Japan)
2 seconds (elsewhere)

S7 (Wait for Carrier After Dial )

Specifies the time that the modem waits for one of the following:

Carrier from the remote modem before hanging up in originate or answer mode
Ringback, only in originate mode, and only if X3 or X4 (Extended Result Codes) is set
Dial tone when the Wait for Dial Tone (W) dial modifier is encountered in a dial string
Quiet answer when the Wait for Quiet Answer (@) dial modifier is included in a dial string

Range

5 to 50 seconds (Japan)
0 to 255 seconds (elsewhere)

Default

50 seconds (Japan)
60 seconds (elsewhere)

S8 (Pause Time for Dial Delay)

Specifies the time the modem waits when the pause dial modifier (,) is used in a dial string.

Range

0 to 255 seconds

Default

S9 (Carrier Detect Response Time )

Specifies the time that a signal must be present before the modem recognizes it as carrier. Register S9 is only used in normal and direct modes.

Range

0 to 255 (0.1-second increments)

Default

6 (0.6 seconds)

S10 (Delay for Hangup After Carrier Loss )

Specifies the time the modem waits before hanging up after loss of carrier, allowing for a temporary loss. Both modems should have equal values set. If the S10 values of the two modems are unequal, disconnection occurs when the lower value is reached. When register S10 is set to 255, the modem functions as if carrier is always present. After disconnecting, the modem waits a minimum of five seconds before going off-hook in originate mode.

Note Register S10 is ignored in V.34, V.32, V.32 bis, V.22, and V.22 bis reliable connections.

Range

0 to 255 (0.1-second increments)

Default

60 (6 seconds)

S11 (DTMF Tone-Dialing Speed)

Specifies the time interval in milliseconds between tones when the modem is dialing over a tone line.

Range

70 to 100 milliseconds (Japan)
50 to 100 milliseconds (elsewhere)

Default

70 milliseconds (Japan)
50 milliseconds (elsewhere)

S12 (Escape Code Guard Time and Remote Access Attention Sequence Guard Time)

Sets the minimum quiet time before and after the three-character escape code. The interval between characters in the escape code or remote access attention sequence must be less than this guard time. If S12 is zero, the time to enter the escape code or attention sequence does not affect recognition.

In normal mode, register S12 sets the guard time that precedes and follows the attention character sequence. It should be set to the same value on both the originating and answering modems. Reliable mode uses its own timing and ignores register S12.

Range

0 to 255 (0.02-second increments)

Default

50 (1 second)

S14 (Bit-Mapped Register )

Note Pulse dialing (bit 5) is not supported in Japan.

Table 69: Register S14 Functions
Bit Meaning Value

0

Not used

-

1

Command echo

0 No echo
1 Echo

2

Result codes

0 Result codes
1 No result codes

3

Result type

0 Short form
1 Long form

4

Dumb mode

0 Smart mode
1 Dumb mode

5

Dial method

0 Tone dial
1 Pulse dial

6

Not used

-

7

Originate/answer

0 Answer mode
1 Originate mode

S16 (Bit-Mapped Register for Test Options)

Register S16 is a read-only register that displays loopback test option status and is available only when the modem is in normal or direct mode. The modem does not support diagnostic tests in Bell 103, V.13, V.21, or V.23 modes. The register is bit-mapped for the functions listed in Table 70.

Table 70: Register S16 Functions
Bit Meaning Value

0

Local analog loopback

0 Disabled
1 Enabled

1

Not used

-

2

Local digital loopback

0 Disabled
1 Enabled

3

Remote digital loopback status
(initiated by the remote modem)

0 Loopback off
1 Loopback in progress

4

Initiate remote digital loopback

0 Disabled
1 Enabled

5

Initiate remote digital loopback with self-test

0 Disabled
1 Enabled

6

Initiate local analog loopback with self-test

0 Disabled
1 Enabled

7

Not used

-

S18 (Test Timer )

Specifies the maximum elapsed time for a modem loopback diagnostic test. Register S18 is available only when the modem is in normal or direct mode. If the register is set to zero, enter the &T0 command (End Test in Progress) to end a test. Register S18 is not supported for V.54 loopback tests by switch or circuit.

Range

0 to 255 seconds

Default

0 (disables the timer)

S21 (Bit-Mapped Register)

Table 71: Register S21 Functions
Bit Meaning Decimal Value

0

Telco jack

0 Default.

1 Not supported.

1

Not used

-

2

Clear To Send/
Request To Send

0 On-hook: CTS on. Off-hook: V.22 and V.22 bis CTS off until connecting. After connecting: CTS is off in response to an on-to-off RTS transition; CTS is on in response to an off-to-on RTS transition after the delay time set in register S26.

1 On-hook: CTS on. Off-hook: CTS off until connecting. After connecting: CTS on for duration of carrier signal.

3, 4

Data Terminal Ready

0 Ignores DTR.

1 On-to-off DTR transition: modem enters command state.

2 On-to-off DTR transition: modem is set on-hook.

3 On-to-off DTR transition: modem reset.

5

Data Carrier Detect

0 DCD always on.

1 DCD on indicates data carrier is present except momentarily at disconnect.

6

Not used

-

7

Long space disconnect

0 Disabled.

1 Enabled.

S22 (Bit-Mapped Register )

Table 72: Register S22 Functions
Bit Meaning Decimal Value

0-3

Not used

-

4, 5, 6

Result code options

0 Same as X0

4 Same as X1

5 Same as X2

6 Same as X3

7 Same as X4

7

Make/break ratio

0 Make 39 percent, break 61 percent

1 Make 33 percent, break 67 percent

S23 (Bit-Mapped Register )

Table 73: Register S23 Functions
Bit Meaning Decimal Value

0

Respond to remote digital loopback (ignored in reliable connections)

0 Disabled

1 Enabled

1, 2, 3

Serial port bps rate

0 0 to 300 bps

1 600 bps

2 1200 bps

3 2400 bps

4 4800 bps

5 9600 bps

6 19200 bps

7 38400, 57600, or 115200 bps

4, 5

Parity

0 Even

1 Space/none

2 Odd

3 Mark

6, 7

Guard tone

0 Disabled

1 550 Hz

2 1800 Hz

3 Not used

S25 (Delay to DTR and Asynchronous/Synchronous Time Delay)

The modem ignores an on-to-off transition of DTR that is less than the register S25 time delay.

Range

0 to 255 (0.01-second increments for Delay to DTR, 1 second for asynchronous mode)

Default

5 (0.05 seconds for Delay to DTR, 5 seconds for asynchronous mode)

S27 (Bit-Mapped Register )

Table 74: Register S27 Functions
Bit Meaning Decimal Value

0, 1

Not supported

-

2, 3, 4, 5

Not used

-

6

Answer tone at 1200 bps

0 CCITT V.22 bis/V.22

1 Bell 212A

7

Not used

-

:T Register Descriptions

This section describes the purpose and format of each supported :T register.

:T0 (Timer for V.22 bis, V.22, and V.32 Modes During Multi-Protocol Answer)

Register :T0 sets the time limit for the modem to establish a V.32, V.22 bis, or V.22 connection before switching to establish a V.23 split speed or V.21 connection. In this time period, the modem sends V.22 bis or V.22 carrier. This register setting requires 1200-bps or higher operation with %F0%L1.

Range

0 to 255 (0.1-second increments)

Default

40 (4 seconds)

:T3 (Timer for V.21 and V.23 Answer Tone Duration)

In answer mode, register :T3 sets the time limit for the V.25 answer tone sent by the answering modem to the originating modem. When :T3 is zero, no answer tone is sent. All V.21 and V.23 answers begin with two seconds of silence before sending an answer tone, unless :T3 is zero.

In originate mode, register :T3 sets the time the originating modem waits after detecting an answer tone before proceeding with the connection. When :T3 is zero, the originating modem does not wait for an answer tone.

Range

0 to 33 (0.1-second increments)

Default

33 (3.3 seconds)

:T4 (Timer for Line Turnaround Delay and Carrier On)

Register :T4 specifies the minimum time that the modem waits for the remote modem to respond after turning carrier off before turning carrier back on again to resume sending data. Register :T4 is used only in normal mode V.23 half-duplex connections.

Range

0 to 255 (12.5-millisecond increments)

Default

20 (250 milliseconds)

:T6 (Timer for DCD Turn On Delay)

Register :T6 specifies the time that the modem waits after it raises carrier before it starts looking for data. This register can be set to ignore noise that occurs when DCD is raised in V.23 half-duplex connections. If :T6 is set to zero, the modem waits 256 milliseconds before looking for data. Register :T6 is used only in normal mode V.23 half-duplex connections.

Range

0 to 255 milliseconds

Default

200 milliseconds

:T9 (Primary XON Flow Control Character)

Register :T9 specifies the character used for primary XON flow control on the modem and serial ports. Both modems must use the same primary flow control characters during normal connections. Use the \ Q1 or \ Q4 command (Serial Port Flow Control), and \G1 or \G2 command (Modem Port Flow Control) to specify primary flow control.

Range

0 to 255 (decimal value of an 8-bit ASCII character)

Default

17 (DC1 or 11 hexadecimal)

:T10 (Primary XOFF Flow Control Character)

Register :T10 specifies the character used for primary XOFF flow control on the modem and serial ports. Both modems must use the same primary flow control characters during normal connections. Use the \ Q1 or \ Q4 command (Serial Port Flow Control) options, and \G1 or \G2 command (Modem Port Flow Control) options to specify primary flow control.

Range

0 to 255 (decimal value of an 8-bit ASCII character)

Default

19 (DC3 or 13 hexadecimal)

:T11 (Secondary XON Flow Control Character)

Register :T11 specifies the character used for secondary XON flow control on the modem's serial port. Use the -F1\ Q1 or -F1\ Q4 commands to specify secondary flow control.

Range

0 to 255 (decimal value of an 8-bit ASCII character)

Default

249 (F9 hexadecimal)

:T12 (Secondary XOFF Flow Control Character)

Register :T12 specifies the character used for secondary XOFF flow control on the modem serial port. Use the -F1\ Q1 or -F1\ Q4 commands to specify secondary flow control.

Range

0 to 255 (decimal value of an 8-bit ASCII character)

Default

251 (FB hexadecimal)

:T14 (Connect Message Delay Timer)

Register :T14 specifies the time that the modem waits before or after a connect message before CTS, DSR, or DCD is raised. Use this register setting with the @C0 or @C1 command (CTS, DSR, and DCD Message Control options).

Range

0 to 255 (100-millisecond increments)

Default

:T16 (CTS Turn On Delay Timer)

Register :T16 specifies the time that the modem waits before raising CTS after DCD or DSR has been raised in connect mode.

Range

0 to 255 (12.5-millisecond increments)

Default

:T17 (V.32/V.32 bis Connection Training Timer)

Register :T17 specifies the time limit for exchanging training sequences when establishing V.32 and V.32 bis connections.

To reduce the time required to establish a connection (but increase the modem's sensitivity to noise on the line), set :T17 to a value less than 28.

To reduce the modem's sensitivity to noise (but lengthen the time required to make a connection), set :T17 to a value greater than 28.

Range

0, 1, or 5 to 32 seconds

Default

0 (use dynamic training sequences, equivalent to a setting of 28)

:T19 (Bit-Mapped Register)

Table 75: Register :T19 Functions
Bit Meaning

0

0 Keeps a non-MNP10 1200-bps connection if no MNP link activity is received from the remote modem

1 Disconnects a non-MNP10 1200-bps connection if no MNP link activity is received from the remote modem after 2 minutes

:T22 (DSR Timer)

Register :T22 specifies the time that the modem waits before DSR transitions off after DCD or CTS transitions off in disconnect mode. For example, if \D2 (Serial Port DSR/CTS Control) and &C1 (Serial Port DCD Control) are set when DCD and CTS transition off, the modem waits for the time specified by register :T22 before setting DSR off.

Range

0 to 255 (12.5-millisecond increments)

Default

34 (425 milliseconds)

:T23 (Bit-Mapped Register)

Table 76: Register :T23 Functions
Bit Meaning Value

0, 1, 2, 3

Not used

-

4

Rate negotiation at startup

1 At the start of a V.32 connection, modem examines line quality and sets speed accordingly

2 Disabled

5, 6, 7

Not used

-

:T26 (Bit-Mapped Register)

Default

0
The default should not be changed except when configuring country codes. (See Step 3).

Table 77: Register :T26 Functions
Bit Meaning

0

0 Enables 2-second billing delay.

1 Disables 2-second billing delay. This setting decreases connection time but can affect establishing connections.

1

0 Enables normal answer tone length in V.32 mode.

1 Shortens answer tone length in V.32 mode.

3

0 Disables Quick Ring detection.

1 Enables Quick Ring detection.

:T89 (PoS Configuration)

For more information, see the "PoS Support" section.

Default

0010 (0x2)

Table 78: Register :T89 Functions
Bit Description Meaning

0

ITU or Bell Mode

0 ITU (See B0)

1 Bell (See B1)

1

300/1200 Normal

0 Attempt EC

1 Normal Mode, No EC

2

S-Reg 9 DCD Recognition Delay

0 Use S9

1 Ignore S9

3

Initial 1650 Hz Tx Tone

0 2100 Hz answerback

1 1650 Hz

Notes:

Use ITU V.21/V.22.
Forced Normal Mode at 300/1200.
Use S9 Register Delay before recognizing Carrier.
Use 2100 Hz Answerback Tones.
Bit 1 of :T89 is now defaulted to a 1 (:T89=2). This forces a Normal Mode connection at 300 bps. If this bit is off, an MNP connection is attempted.
If the bit is on (answer modem), and the originate modem is set to \N2, no connection results.
To support Bell 103 PoS terminals, set :T89 to 7.
To support V.21 PoS terminals, set :T89 to 6.
If V.23 is supported and PoS/QUICK 300 is not, NORMAL mode is forced in the case of a V.23 connection (:T89 has no effect in this case).

:T120 (Answerback Tone Duration)

For more information, see the "PoS Support" section.

Default

11001 (0x19, 25 decimal) for 2500 milliseconds of 1650 Hz tone

:T121 (Answerback Tone Configuration for PoS)

For more information, see the "PoS Support" section.

Default

11011 (0x1B, 27 decimal) 2700 milliseconds answerback tones

Debugging

The @E command (detailed modem call status) is an unofficially supported modem status and debugging command that can be used by an experienced user to verify the detailed status of the modem during or after a call. The content of this command might change as required to assist in problem resolution. Therefore, the command might produce results that differ from the description in this section.

The @E0 command results in a single-screen display (press any key for the next screen). The @E1 command results in continuous screen display. Press Ctrl-X or Break to cancel the display.

This is a sample of an @E report:

at@e1
 
 
MNP Class 10 V.34 Modem 
MODEM HW: OEM 2W United States
Firmware Rev x.x.x/85
Bootstrap Rev y.y.y
DSP C36 Part/Rev              3035 4241
DSP C58 Part/Rev              3035 2041
NET ADDR:      FFFFFFFFFFFF
Connect Time HH:MM:SS         000:02:01
4 RTS 5 CTS 6 DSR - CD 20 DTR - RI 
Disconnect  Remote -   Local - 14,10,9
 
CONNECTION STATUS             
Mod Type                      IDLE
TX/RX Spd                     600 600 BPS
TX/RX Spd Mask                   NA  0000 Hex
TX/RX Symbol Rate              2400  2400 Hz
TX/RX Carrier Frequency        1800  1800 Hz
TX/RX Trellis Code States        16    16
TX/RX Nonlinear Encoding        OFF   OFF
TX/RX Precoding                 OFF   OFF
TX/RX Shaping                   OFF   OFF
TX Preemphasis Index              0
TX Lvl Reduction                  0 dB
Secondary Channel               OFF
 
LINE IMPAIRMENTS              
TX Lvl REG                     - 10 dBm
TX Lvl RAM                     -  0 dB
TX Lvl Reduction                  0 dB
TX Lvl                         - 10 dBm
RX Lvl                         - 16 dBm
Signal/Noise Ratio                0
Signal/Distortion Ratio           0
Eye Quality                    0000 Hex
Lower Band Edge                   0 Hz
Upper Band Edge                   0 Hz
Phase Jitter Freq                 0 Hz
Phase Jitter Amp                0.0 deg
Far Echo Offset (Phase Roll)    0.0 Hz
Far Echo Lvl = 20log(N)-81        0 N
Round Trip Delay                  0 msec
Dropouts > 5dB                    0
RTRNs Initiated                   0
RTRNs Accepted                    0
Rate Changes Initiated            0
Rate Changes Accepted             0
FF Trip/Block Error Rate       0000 Hex
                              
EQM FUNCTION STATUS           
AVG EQM Filter Pole            8A25 Hex
EQM Gain                       8A4E Hex
EQM Offset                     8A77 Hex
AVG EQM Filter Pole            8AA0 Hex
AVG EQM Baud Interval          8AC9 Hex
AVG EQM Sample Size            8AF2 Hex
AVG EQM                        8B1B Hex
EQM Threshold Lvl              8B44 Hex
 
OK

Table 79 describes components of the report. The table does not include self-explanatory fields.

Table 79: AT@E Report Description
Field Description

Firmware Rev

Current firmware version

Bootstrap Rev

Current boot version

DSP C36 Part/Rev

Current DSP version

DSP Controller Rev

Current DSP hardware

DSP Data Pump Rev

Current DSP controller pump

Mod Type

Modulation type---the modulation standard being implemented on the current connection. If no connection is established, it reads IDLE.

TX/RX Spd

TX/RX Speed---transmitter and receiver modulation speeds for the current connection. The TX/RX speeds may be different for operating modes that support split-speed operation, such as V.34. Given in bits per second.

TX/RX Spd Mask

TX/RX speed mask---a hex number that shows which speeds the Rockwell DSP is configured to support on a given connection. For V.34, the LSB represents 2400 bps (1=on, 0=off); the next significant bit represents 4800 and so on up to 33.6 kbps.

Symbol Rate

TX/RX symbol rate---a hex number that shows which symbol rate (analog signal event rate) the Rockwell DSP is currently using. For most modes, this is a fixed number, but V.34 negotiates any of six different rates from 2400 to 3429 symbols/second.

TX/RX Carrier Freq

TX/RX carrier frequency---a single-frequency sinusoid that is modulated to transmit binary information in accordance with the selected operating modes. This also is usually a fixed number, except for V.34, where nine different values can be chosen. In the V.34 case, a low and a high carrier are available for each of the symbol rates. The appropriate symbol rate and its associated carrier are selected by the modem during the startup sequence. Given in hertz.

TX/RX States

TX/RX Trellis Code States

TX/RX Trellis states---Trellis Encoding is a method for improving noise immunity using a convolutional coder to select a sequence of subsets in a partitioned signal constellation. The trellis encoders used in the V.34 Recommendation are used in a feedback structure where the inputs to the trellis encoder are derived from the signal points. For V.34, this parameter tells whether 16, 32, or 64 state encoding is being used.

TX/RX Nonlinear Encoding

TX/RX NLE

TX/RX nonlinear encoding---a method for improving distortion immunity near the perimeter of a signal constellation by introducing a non-uniform two-dimensional (2D) signal point spacing.

TX/RX Precoding

TX/RX precoding---a nonlinear equalization method for reducing equalizer noise enhancement caused by amplitude distortion. Equalization is performed at the transmitter using precoding coefficients provided by the remote modem.

TX/RX Shaping

TX/RX shaping---a method by which the noise margin of a modem signal can be maximized by forming signal constellations in high-dimensional spaces, thereby reducing the average signal power. V.34 modems use a shell mapping mechanism to achieve a near-spherical signal constellation, yielding a shaping gain of around 1 dB.

TX Preemphasis Index

TX pre-emphasis index---reads the remote modem's PRE-emphasis Request byte value. Pre-emphasis is a linear equalization method where the transmit signal spectrum is shaped to compensate for amplitude distortion. The pre-emphasis filter is selected using a filter index provided by the remote modem; the filters conform to the 11 types outlined in the ITU specifications for the given operating mode.

Secondary Channel

Secondary channel---on or off. The auxiliary channel is a reduced bandwidth data channel which, along with the primary channel, is multiplexed into the bit stream transmitted by the modem. Data conveyed in the auxiliary channel is independent from the primary channel and may consist of secondary channel data and modem control data. The secondary channel is a portion of the auxiliary channel that is made available to the user.

Line Impairments

TX Lvl REG

Transmit level register---the transmit level the modem is configured for. Given in dBm (decibels referenced to 1 milliwatt through 600 ohms).

TX Lvl RAM

Transmit level RAM---the transmit level gain the modem is configured for. The gain may be positive or negative and is used to adjust the transmit level separately from the transmit level configuration. Given in dBm.

Tx Lvl Reduction

TX Lvl Reduct

Transmit level reduction---the reduction in transmit level (power drop), if any, that has been negotiated by the modems during handshake. Given in dBm. Valid in V.34 mode only.

TX Lvl

Transmit level ---the transmit level the modem actually uses; consists of the configured level plus the tx level gain minus the negotiated power drop. Given in dBm.

RX Lvl

Receive level---the signal level the modem receiver is detecting. Given in dBm. The following table gives a range of common values for V.34:

-15 to -25 dBm (excellent/optimum)
-26 to -30 dBm (good)
-31 to -35 dBm (fair)
-36 to -42 dBm (poor)
-43 to -48 dBm (connect/no connect threshold)

Signal/Noise Ratio

S/NR

Signal/noise ratio---the ratio or margin between the received signal level and the noise level detected by the receiver, in dBm. The following table gives a range of common values versus connect speed (V.34):

SNR Typical V.34 connect speed *

>=46 dBm 33600

45 dBm 31200

44 dBm 28800

42 dBm 26400

39 dBm 24000

35 dBm 21600

32 dBm 19200

31 dBm 16800

29 dBm 14400

27 dBm 12000

24 dBm 9600

22 dBm 7200

19 dBm 4800

16 dBm 2400

* These are empirical values measured in the absence of other impairments. Actual values may vary. Ideal conditions use ISDN-PRI.

Signal/distortion ration

S/DR

Signal/distortion ratio---the ratio or margin between the received signal level and the harmonic distortion level detected by the receiver.

Eye Quality

EQM

Eye quality measurement---the quality of the analog signal. A low number indicates good quality with 0 being the best possible; a high value is considered poor. The modem uses EQM in its rate decision mechanism. Given as a hex number. The following table gives a range of common values (V.34):

< 1000 (good)

to 2000 (fair)

to 3000 (poor)

AVG EQM

Average eye quality---the output of the EQM averaging mechanism. Initial value is 0000 Hex.

Lower/Upper Edge

Lower band edge/upper band edge---the channel low and high bandwidth edge estimates (in hertz) generated by the V.34 handshake probing.

Phase Jitter Freq

Phase jitter frequency---Phase jitter is a deviation in the phase of an analog signal having frequency in hertz and magnitude in degrees. It results in a pure tone having an associated FM spectrum. In some cases, this spectrum is random and in others it takes the form of discrete multiples and submultiples of AC power frequencies. It can be caused by coupling through from power line associated equipment such as ringing generators.

Phase Jitter Amp

Phase jitter amplitude---Phase jitter is a deviation in the phase of an analog signal having frequency in hertz and a magnitude in degrees. It results in a pure tone having an associated FM spectrum. In some cases, this spectrum is random and in others it takes the form of discrete multiples and submultiples of AC power frequencies. It can be caused by coupling through from power line associated equipment such as ringing generators.

Far Echo Offset (Phase Roll)

Far echo offset---how much far end echo frequency offset is present. Given in hertz.

Far Echo Lvl

Far echo level---the power level of the far echo. The value in dBm can be obtained from level = 20 log N - 81.

Round Trip Delay

Round trip delay the time delay that a signal encounters on a connection. For instance, If a call is routed over a satellite hop, the delay in one direction is approximately 500 milliseconds; round trip delay is approximately 1000 milliseconds. The initial value is 0 milliseconds.

Dropouts >5dB

Dropouts >5dB---how many signal dropouts greater than 5 dBm have occurred during the current connection. The initial value is 0.

RTRNs Init/Accept

Retrains initiated---how many retrains have been initiated by the local modem during the current connection. A retrain is a repetition of most of the modem startup or handshake sequence after the modems have been connected. It usually occurs in response to disruptions of the communications channel or user intervention.

Retrains accepted---how many retrains have been accepted by the local modem during the current connection.

Rate Changes Inititated/Accepted

RRENs Init/Accept

Rate renegotiations initiated---how many rate renegotiations have been initiated by the local modem during the current connection. A rate renegotiation is a brief exchange of rate and signal quality information between modems and is used to upshift or downshift the modulation rate after the modems have been connected (much shorter than a full retrain). It usually occurs in response to changes in signal quality or user intervention.

Rate renegotiations accepted how many rate renegotiations have been accepted by the local modem during the current connection.

FF Trip/Block Error Rate

BLER

Block errors---how many block errors occur over a reliable connection (that is, a connection that has a successfully negotiated error correction protocol).

RBS Counter

Robbed bit signaling counter---the number of bits robbed by the channelized T1 links in the transmission path.

Digital Pad Detected

Digital pad detected---expected values are 0, 3, or 6 dB.

Avg EQM Filter Pole

Average EQM filter pole---the bandwidth of the EQM low pass filter. The default is 0000 Hex.

EQM Gain

EQM gain---adjusts the rate decision mechanism. A higher number results in a more reliable connection; a lower number results in a less reliable connection. The default is 1000 Hex.

EQM Offset

EQM offset---adjusts the rate decision mechanism. A positive number results in a more reliable connection; a negative (twos complement) number results in a less reliable connection. The default is 0000 Hex.

AVG EQM Baud Interval

Average EQM baud interval---number of symbol intervals or periods between EQM samples. These samples are used to compute a time average of the EQM value. If it is 0, the EQM averaging function is shut off. The default is 0000 Hex.

AVG EQM Sample Size

Average EQM sample size---the number of EQM samples to be run through the EQM LPF. Default is 0000 Hex.

EQM Threshold Level

EQM threshold level---trigger threshold for the Rockwell EQMAT. When the EQM value exceeds this threshold, EQMAT bit is set. The modem uses this for performance decisions. The default is 3000 Hex.

PoS Support

Analog modems incorporate a series of adaptations for PoS quick connects in Europe that are defined best under two sets of modifications. The objective is to enable an immediate V.21 without answer tone for 300 bps PoS and then train up to V.22 with answer tone for 1200 bps PoS. By default, the configuration is locked to 8 bit data, no parity, 1 start, 1 stop bit, and normal mode connections.

Registers :t89, :t120, and :t121 have been allocated to enable 300/1200 quick connections, error correction, pause for DCD to be true, and tone duration timers.

An incoming call is answered and the answer modem sends out 1650 Hz immediately. The PoS device can send back 980 Hz if configured to do so. Note bit 3 of :t89 in the ".

The answer modem detects the data carrier---in this case within 5 milliseconds---at which time the PoS device initiates the transaction request. If the device calling is not a quick connect V.21 device then the 1650 Hz timer expires (duration of 1650 Hz declared in :t120) and the answer modem ill then trains up for 1200 bps and send out 2100 Hz answerback tones (duration of answerback tones declared in :t121). The standard answerback period of 3 seconds (+/- 20%) is modifiable by :t121.

Two AT commands for the command parser enable spawning early SVC circuit building while the modems are engaged in the modulation handshake. This assures that there is no latency for SVC set up and network overhead. These new commands, &C3 and \D4, lower CTS and raise DCD upon incoming call detection and going off-hook.

:&C3\D4 Definition

The &C3 and \D4 AT commands are incorporated to permit aggressive SVC circuit building while the modems handshake. The X.25 SVC circuit is spawned upon recognition of DCD active at the end of a modem handshake when the modem goes to data mode.

\D4 permits ITU signal control for DSR/CTS. This is used with the command &C3 to enable the following sequence:

Step 1 Incoming Call Detection is set to Modem Off-Hook.

Step 2 CTS is lowered to the host interface in order to disable the host transmit, assuring that no data is sent to the modems during training, and that any data sent from the network host before modem training is complete is held in the transmit queue and forwarded when CTS is presented active again.

Step 3 Raise DCD to spawn the PoS SVC circuit building to the remote authorization host.

Step 4 Send back the 1650 Hz and/or 2100 Hz train up answer sequence and establish carrier and data mode with the external dialing device.

Step 5 CTS is presented as active to enable the host transmit and forwards the host transaction responses.

The early circuit build or SVC spawning works well with or without 1200/2400 fast-transaction support. The training up from 300 to 1200 feature is absolutely essential for Europe, as 300 bps PoS devices do not handle the 2100 Hz answerback tones, and they fail and disconnect if a traditional handshake and downspeed shift is attempted.

For help with questions or problems, contact Cisco Systems as described in the "Cisco Connection Online" section.

PoS Field Applications

The PoS feature is deployed with two main types of PoS devices. One device is a low-speed, instant connect V.21 terminal, which dictates that the modems train up, not down, as would typically be the case with Central Site Modems.

The actual initialization string for a European client might be exactly as described in the following example. Note that the string includes the country code specific profile.

Caution You cannot apply a country code -IxZ command in the PoS modemcap---the PoS features is either ignored or removed with the associated country reset. The specialized PoS train up and quick-connect features are ITU (V.21/V.22) specific. This dictates that you remove any country code modemcap and apply any country-specific requirements as part of your PoS modemcap.

The early circuit spawning feature available with \D4&C3 is completely independent of any ITU or Bell mode and can be used to accelerate PoS transaction times to pre-build sessions as the modems complete handshake sequences.

The &C3 command is never used without the \D4 command. The two commands are interlocked for the PoS feature. For more information, see the "\Dn (Serial Port DSR/CTS Control)" section and the "&Cn (Serial Port DCD Control)" section.

Example of Modemcap Creation, Assignment, and Audit

Enter router configuration mode and create a global modemcap as follows:

Router# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config) #modemcap edit your_config factory &f&d0%d2@c0b0%m0\n0 
Router(config) #modemcap edit your_config misc
%u0%g1%b1200%u1:t89=14:t121=015:t51=14\d4&c3
Router(config) #line 11
Router(config-line) #mod auto type your_config
Router(config-line) #exit
Router(config) #exit

Note For 300/1200 Bell devices, the :t89 and associated registers have no effect at this time.

Use the debug command debug confmodem to audit the modem profile:

Router# deb confmodem
Modem Configuration Database debugging is on
Router #cle li 11
[confirm]
[OK]
Router# Dec 11 15:58:20 PST: TTY11: Line reset by "Exec"
Dec 11 15:58:20 PST: TTY11: Modem: IDLE->HANGUP
Dec 11 15:58:20 PST: TTY11: dropping DTR, hanging up
Dec 11 15:58:20 PST: tty11: Modem: HANGUP->IDLE
Dec 11 15:58:25 PST: TTY11: restoring DTR
Dec 11 15:58:26 PST: TTY11: autoconfigure probe started
Dec 11 15:58:26 PST: TTY11: Modem command:
--AT&f&d0%d2@c0b0%m0\n0%u0%g1%b1200%u1:t89=14:t121=015:t51=14\d4&c3--

Cisco Connection Online

Cisco Connection Online (CCO) is Cisco Systems' primary, real-time support channel. Maintenance customers and partners can self-register on CCO to obtain additional information and services.

Available 24 hours a day, 7 days a week, CCO provides a wealth of standard and value-added services to Cisco's customers and business partners. CCO services include product information, product documentation, software updates, release notes, technical tips, the Bug Navigator, configuration notes, brochures, descriptions of service offerings, and download access to public and authorized files.

CCO serves a wide variety of users through two interfaces that are updated and enhanced simultaneously: a character-based version and a multimedia version that resides on the World Wide Web (WWW). The character-based CCO supports Zmodem, Kermit, Xmodem, FTP, and Internet e-mail, and it is excellent for quick access to information over lower bandwidths. The WWW version of CCO provides richly formatted documents with photographs, figures, graphics, and video, as well as hyperlinks to related information.

You can access CCO in the following ways:

WWW: http://www.cisco.com
WWW: http://www-europe.cisco.com
WWW: http://www-china.cisco.com
Telnet: cco.cisco.com
Modem: From North America, 408 526-8070; from Europe, 33 1 64 46 40 82. Use the following terminal settings: VT100 emulation; databits: 8; parity: none; stop bits: 1; and connection rates up to 28.8 kbps.

For a copy of CCO's Frequently Asked Questions (FAQ), contact cco-help@cisco.com. For additional information, contact cco-team@cisco.com.

Note If you are a network administrator and need personal technical assistance with a Cisco product that is under warranty or covered by a maintenance contract, contact Cisco's Technical Assistance Center (TAC) at 800 553-2447, 408 526-7209, or tac@cisco.com. To obtain general information about Cisco Systems, Cisco products, or upgrades, contact 800 553-6387, 408 526-7208, or cs-rep@cisco.com.

OL - 0034 - 02

Command	Meaning
%U0	Allows the current serial port speed to be changed to any other speed. This option is not required for speeds of 19200 bps and lower.
%U1	Always keeps the current serial port speed. You must enter %U1 each time you change the serial port speed.
%U2	Allows the current serial port speed to be changed from any speed.

Command	Meaning
%V1	Provides detail to the x.x.x level
%V0	Provides detail to the x.x level

Command	Meaning
&C0	DCD is always on.
&C1	DCD follows the state of carrier from the remote system and turns on after the connect message.
&C2	DCD is on except momentarily at disconnect.
&C3¹	DCD goes active at the end of a modem handshake when the modem goes to data mode.

Command	Meaning
&D0	Ignores DTR. DTR is not needed for autoanswer.
&D1	Enters command state on detecting on-to-off transition of DTR. DTR is not needed for autoanswer.
&D2	Sets the modem on-hook when detecting an on-to-off transition of DTR and prepares the serial port to accept an AT command at any speed. DTR is needed for autoanswer.
&D3	Sets the modem on-hook and resets when detecting an on-to-off transition of DTR and prepares the serial port to accept an AT command at any speed. DTR is needed for autoanswer.

Command	Meaning
&G0	Disables the guard tone
&G1	Sets the guard tone on the answering modem to 550 Hz
&G2	Sets the guard tone on the answering modem to 1800 Hz

Command	Meaning
&P0	Make 39 percent, break 61 percent
&P1	Make 33 percent, break 67 percent

Command	Meaning
&S0	DSR is always on. Equivalent to setting the Serial Port DSR/CTS command \D.
&S1	DSR is on with answer tone. Equivalent to setting the Serial Port DSR/CTS command \D3.

Command	Meaning
&T0	Ends a test in progress. The test ends without terminating a connection, returning the local and remote modems to normal operation. If a self-test is in progress, &T0 reports any errors. This command must be the last command on a command line.
&T1	Runs a local analog loopback test. The modem should display characters on your screen exactly as you enter them. The modem must be in normal or direct mode and set to 1200 bps or higher.
&T3	Local digital loopback test. Allows a remote modem that does not support the CCITT V.54 standard to perform a remote digital loopback test with the modem. The modem must be in normal or direct mode and set to 1200 bps or higher.
&T4	Allows the modem to respond to a remote caller's request to enter remote digital loopback mode. The modem must be in normal or direct mode and set to 1200 bps or higher.
&T5	Prevents the modem from responding to a remote digital loopback request.
&T6	Instructs the remote modem to initiate a remote digital loopback test. The modem must be in normal or direct mode and set to 1200 bps or above.
&T7	Instructs the remote modem to enter a remote digital loopback with a self-test. After the test is complete, the remote modem reports errors to the local device. The modem must be in normal or direct mode and set to 1200 bps or above.
&T8	Runs a local analog loopback with a self-test. The modem sends itself the ITU-T V.54 test pattern, verifies characters to make sure they are received correctly, and reports errors to the local device. The modem must be in normal or direct mode and set to 1200 bps or above.

Command	Meaning
)M0	Adjusts the power level for central site modems if the remote modem is set to )M1. Use this option for MNP Class 10 modems that connect to both cellular and noncellular site modems.
)M1	Autoadjusts the power level for cellular modems.

Command	Meaning
-D/n	n is an integer between 1 and 9 that specifies a telephone number stored with the \P command.
-DL	Redials the last number dialed.
-DS	Dials the first entry stored in the directory.

Command	Meaning
-E0	Enables 10-bit data during normal mode connections
-E1	Enables 11-bit data during normal mode connections

Country	Country Code	Country Code Displayed in Banner
Australia	20	49
Austria	22	92
Belgium¹	23	67
Czech/Slovak Republic¹	18	91
Denmark	10	63
Finland	9	71
France¹	25	32
Germany	17	68
Israel	15	16
Italy	3	21
Ireland	24	97
Japan	13	14
Netherlands	5	04
New Zealand	11	55
Norway	8	72
Poland	19	93
Portugal	27	94
Spain	6	76
South Africa	16	69
Sweden	7	09
Switzerland¹	14	66
UK²	2	12
USA³	1	85

Command	Meaning
-K0	Disables MNP extended services
-K1	Enables MNP extended services
-K2	Enables MNP extended services without MNP indication during the answer detect phase

Command	Meaning
-M0	Disables MNP class connect messages
-M1	Enables the following formats for MNP class connect messages, where n equals MNP class (from 1 to 10), and x means the type of data compression (V.42 bis or MNP Class 5): CONNECT for normal and direct connections CONNECT MNPn/x for MNP connections CONNECT MNPn for modems that do not negotiate compression CONNECT MNPn/CELLULAR/x if )M1 (Power Level Adjustment) is set CONNECT LAPM for LAPM connections with no compression active CONNECT LAPM/V42 bis for LAPM V.42 bis connections

Command	Meaning
-O0	7 data bits, odd parity
-O1	7 data bits, even parity
-O2	7 data bits, mark parity
-O3	7 data bits, space parity
-O4	8 data bits, no parity
-O5	8 data bits, odd parity
-O6	8 data bits, even parity
-O7	8 data bits, mark parity

Command	Meaning
-P0	Ignores parity for special characters. All received data is passed to the workstation with parity corrected to match the serial port parity.
-P1	Processes special characters received from the workstation only if their parity matches the serial port parity. All received data is passed to the workstation at 8 data bits with no parity.
-P2	Processes special characters only if their parity matches the serial port parity. Modem port flow control characters are recognized, regardless of whether their parity matches the serial port parity. All received data is passed to the workstation with parity corrected to match the serial port parity.

Command	Meaning
-Q0	Disables fallback from a V.32 bis or V.32 MNP reliable connection to an MNP reliable 2400 or 1200 bps connection
-Q1	Enables fallback from a V.32 bis or V.32 MNP reliable connection to an MNP reliable 2400 bps connection
-Q2	Enables fallback from a V.32 bis or V.32 MNP reliable connection to an MNP reliable 2400 or 1200 bps connection

Command	Meaning
-V0	Enables V.23 split modem port speed connections within the multiprotocol autoanswer feature
-V1	Disables V.23 split modem port speed connections within the multiprotocol autoanswer feature

Command	Meaning
:D0	The modem is not set off-hook when DTR is raised.
:D1	The modem is set off-hook in originate mode when DTR is raised. &Dn (DTR Control) also must be set. For example, if &D2 is set, the modem is set off-hook 5 seconds after recognizing the positive transition of DTR.
:D2	The modem is set off-hook in originate mode and dials the first stored telephone number when DTR is raised. &Dn must also be set.

Command	Meaning
:E0	Disables the compromise equalizer only when the modem is in V.32 mode. Use :E0 only when you are performing back-to-back or PBX-to-PBX V.32 mode connections.
:E1	Enables the compromise equalizer. Use :E1 for outside-line-to-outside-line or PBX-to-outside-line connections.

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