MULTITECH SYSTEMS, INC.

MT2834LT/MT2834LTI

Modem Type

Data (synchronous/asynchronous)/Fax

Maximum Data Rate

28.8Kbps

Maximum Fax Rate

14.4Kbps

Data Bus

PCMCIA Type II

Fax Class

Class I & II

Data Modulation Protocol

Bell 103A/212A

ITU-T V.21, V.22, V.22bis, V.23, V.32, V.32bis, V.34

AT&T V.32terbo

Fax Modulation Protocol

ITU-T V.17, V.21CH2, V.27ter, V.29

Error Correction/Compression

MNP2-5, V.42, V.42bis

Proprietary AT Command Set

AUTO-RELIABLE TIME BUFFER CONFIGURATION

Type:

Configuration

Format:

AT [cmds] $An [cmds]

Example:

AT $A1 &W<CR>

Description:

Controls the handling of incoming data during auto-reliable time period.

Command

Function

í $A0

Data is discarded.

$A1

Data is buffered.

BIT MODE

Type:

Configuration

Format:

AT [cmds] $EBn [cmds]

Example:

AT $EB1 E1<CR>

Description:

Selects 10- or 11-bit mode.

Command

Function

í $EB0

Sets 10-bit mode.

$EB1

Sets 11-bit mode.

CALLBACK NUMBER

Type:

Configuration

Format:

AT [cmds] [+/-]DT<#>Nnn

Examples:

AT#DB2 +-DT555-1212N10<CR>

Description:

Sets the phone number associated with the password at memory location nn.

Command

Function

+DT

Modem will initiate callback on successful login.

-DT

Modem will allow immediate entry on successful login without callback.

+-DT

If password is followed by a -, modem will allow immediate entry. If password is followed by a + or nothing, modem will initiate callback.

CALLBACK PARITY

Type:

Configuration

Format:

AT [cmds] #Pn [cmds]

Example:

AT #P0 #DB1<CR>

Description:

Sets the parity of the modem when in callback mode.

Command

Function

í #P0

No parity.

#P1

Odd parity.

#P2

Even parity.

CALLBACK PASSWORD

Type:

Configuration

Format:

AT [cmds] #CBNnnxxxx

Example:

AT#DB2 #CBN09snarf<CR>

Description:

Sets the callback password at memory location nn to xxxx. The password must be between 6 and 10 characters, inclusive.

CALLBACK SECURITY

Type:

Configuration

Format:

AT [cmds] #DBn [cmds]

Example:

AT #DB1 S0=1<CR>

Description:

Sets the security level of the callback function.

Command

Function

í #DB0

Disables security and clears callback memory.

#DB1

Enables remote security only.

#DB2

Enables local and remote security.

COMMAND ESCAPE TYPE

Type:

Configuration

Format:

AT [cmds] %En [cmds]

Example:

AT %E3 &W<CR>

Description:

Sets type and response of command escape sequence.

Command

Function

%E0

Command escape disabled.

í %E1

TIES escape (+++AT...)

%E2

<BREAK>AT method.

%E3

Both TIES and BREAK methods.

%E4

OK response to command escape disabled.

%E5

OK response to command escape enabled.

COMMAND SET

Type:

Configuration

Format:

AT &Qn

Example:

AT &Q1<CR>

Description:

Selects standard Hayes or custom command sets.

Command

Function

í &Q0

Multi-Tech custom command set enabled.

&Q1

Standard Hayes command set enabled.

COMPRESSION

Type:

Configuration

Format:

AT &En

Example:

AT &E15 #L0<CR>

Description:

Selects data compression.

Command

Function

&E14

Data compression disabled.

í &E15

Data compression enabled.

COMPRESSION MODE

Type:

Configuration

Format:

AT #Ln

Example:

AT #L2 DT555-1212<CR>

Description:

Selects active compression protocols.

Command

Function

í #L0

V.42 negotiation enabled.

#L1

MNP negotiation enabled.

#L2

LAP-M negotiation enabled.

#L3

LAP-M enabled, no negotiation.

CTS SIGNAL

Type:

Configuration

Format:

AT [cmds] &RFn [cmds]

Example:

AT &RF0<CR>

Description:

Selects the function of the CTS signal.

Command

Function

&RF0

CTS is set to RTS.

í &RF1

CTS is independent of RTS.

DIAL STORED PHONE NUMBER

Type:

Immediate

Format:

AT [cmds] Nn1 [Nn2, Nn3...]

Example:

ATM0 N1N3N5<CR>

Description:

Dials stored phone number(s). If the first number is busy, the modem will proceed to the next number in the list.

DSR SIGNAL

Type:

Configuration

Format:

AT [cmds] &SFn [cmds]

Example:

AT &SF0<CR>

Description:

Selects the function of the DSR signal.

Command

Function

í &SF0

DSR is set to CD.

&SF1

DSR is independent of CD.

DTR DIALING

Type:

Configuration

Format:

AT [cmds] $Dn [cmds]

Example:

AT $D1 DT555-1212<CR>

Description:

Turns DTR dialing on and off.

Command

Function

í $D0

DTR dialing disabled.

$D1

DTR dialing enabled.

DTR TIMEOUT

Type:

Register

Format:

AT [cmds] S24=n [cmds]

Example:

ATS24=40<CR>

Default:

20

Range:

0-255

Unit:

50 ms

Description:

Sets the time to drop the DTR signal to hangup.

ERASE CALLBACK PASSWORD

Type:

Immediate

Format:

AT [cmds] #RCBNn [cmds]

Example:

AT #RCBN05 #RDN05<CR>

Description:

Erases the callback password at the memory location specified.

ERASE CALLBACK NUMBER

Type:

Immediate

Format:

AT [cmds] #RDNn [cmds]

Example:

AT #RCBN05 #RDN05<CR>

Description:

Erases the callback phone number at the memory location specified.

ERROR CORRECTION DISABLE ON CONNECT

Type:

Configuration

Format:

AT [cmds] $Fn [cmds]

Example:

AT $F1 DT555-1212<CR>

Description:

Selects whether error correction can be disabled by a <CR> while handshaking.

Command

Function

$F0

Error correction handshake interrupt disabled.

í $F1

Error correction handshake interrupt enabled.

ESCAPE SEQUENCE BUFFER SIZE

Type:

Register

Format:

AT [cmds] S34=n [cmds]

Example:

ATS34=30<CR>

Default:

10

Range:

0-60

Unit:

1 byte

Description:

Sets the size of the buffer used to store commands during an escape sequence.

ESCAPE SEQUENCE - OUT OF BAND

Type:

Immediate

Format:

<BREAK> AT [cmds]<CR>

Example:

<BREAK> AT #F1<CR>

Description:

Puts the modem in Command Mode.

Notes:

Do not precede this command with AT.

<BREAK> refers to the hardware modem break signal.

ESCAPE SEQUENCE TIMEOUT

Type:

Register

Format:

AT [cmds] S32=n [cmds]

Example:

ATS32=30<CR>

Default:

20

Range:

0-255

Unit:

1 second

Description:

Sets the maximum amount of time the modem will wait for a <CR> while executing an escape sequence.

FACTORY DEFAULTS

Type:

Immediate/Configuration

Format:

AT &F[n]

Example:

AT &F8<CR>

Description:

Loads factory defaults, or sets write protect on NVRAM.

Command

Function

&F

Reloads defaults by setting. (Immediate, see below.)

í &F8

Sets &F to read factory defaults from ROM, and disables NVRAM write protect.

&F9

Sets &F to read defaults from NVRAM, and enables write-protect.

FALLBACK MODE

Type:

Configuration

Format:

AT [cmds] #Fn [cmds]

Example:

AT #F1 O<CR>

Description:

Sets direction of fallback.

Command

Function

#F0

Fallback disabled.

#F1

Fallback from 28.8Kbps to 2400bps as line quality degrades.

í #F2

Fallback from 2400bps to 28.8Kbps as line quality improves.

FLOW CONTROL NORMAL MODE

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E11 O<CR>

Description:

Selects normal flow control.

Command

Function

í &E10

Normal mode disabled.

&E11

Normal mode enabled.

FLOW CONTROL TYPE

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E4 &W<CR>

Description:

Sets type of flow control used by modem.

Command

Function

&E3

Flow control disabled.

í &E4

CTS/RTS flow control enabled.

&E5

XON/XOFF flow control enabled.

HANDSHAKE ATTEMPTS

Type:

Configuration

Format:

AT [cmds] #An [cmds]

Example:

AT #A1 #L3<CR>

Description:

Configures the initial handshake phase.

Command

Function

#A0

Attempts in order: 28.8Kbps, 24Kbps, 19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps, 4800bps, 2400bps, 1200bps, 300bps.

#A1

Attempts only 28.8Kbps.

#A2

Attempts in order: 28.8Kbps, 24Kbps, 19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps, 4800bps.

#A3

Attempts in order: 2400bps, 1200bps, 300bps.

HELP SCREENS

Type:

Immediate

Format:

AT $Hn

Example:

AT $H1<CR>

Description:

Shows modem help screens.

Command

Function

$H1

Shows help screen 1.

$H2

Shows help screen 2.

$H3

Shows help screen 3.

LIST CONFIGURATION

Type:

Immediate

Format:

AT Ln

Example:

AT L5<CR>

Description:

Lists modem configuration.

Command

Function

L5

Lists all settings.

L6

Lists the values of all S-registers.

L7

Lists extended parameters.

L8

Lists current diagnostics.

LOCAL SERIAL PORT SPEED

Type:

Configuration

Format:

AT [cmds] $SBnnn [cmds]

Example:

AT $MB9600 $SB19200<CR>

Description:

Sets serial port speed.

Command

Function

$SB300

Sets 300bps speed.

$SB1200

Sets 1200bps speed.

$SB2400

Sets 2400bps speed.

$SB4800

Sets 4800bps speed.

$SB9600

Sets 9600bps speed.

$SB19200

Sets 19.2Kbps speed.

$SB38400

Sets 38.4Kbps speed.

$SB57600

Sets 57.6Kbps speed.

$SB115200

Sets 115.2Kbps speed.

LOCK SERIAL PORT

Type:

Configuration

Format:

AT [cmds] $BAn [cmds]

Example:

AT $SB57600 $BA0<CR>

Description:

Sets operation of serial port speed.

Command

Function

í $BA0

Serial speed locked at rate set by $SB.

$BA1

Serial speed follows connect speed, ignoring $SB.

LOGIN PASSWORD

Type:

Configuration

Format:

AT [cmds] #Ixxxx

Example:

AT #IMicroHouse<CR>

Description:

Sets the login password to xxxx. The password must be between 6 and 10 characters, case sensitive. It defaults to MULTI-TECH.

MAXIMUM BLOCK SIZE FOR TRANSMISSION

Type:

Configuration

Format:

AT [cmds] &BSn [cmds]

Example:

AT &BS1 &MB28800<CR>

Description:

Sets the maximum transmittable block size.

Command

Function

&BS0

Maximum block size is 64 characters.

í &BS1

Maximum block size is 128 characters for LAP-M, and 256 characters for MNP.

PACING

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E13<CR>

Description:

Selects ENQ/ACK pacing.

Command

Function

&E12

Disables ENQ/ACK pacing.

í &E13

Enables ENQ/ACK pacing.

PACING - ENQ/ACK

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E9<CR>

Description:

Selects ENQ/ACK pacing.

Command

Function

í &E8

Enables ENQ/ACK pacing.

&E9

Disables ENQ/ACK pacing.

POWER SAVING MODE

Type:

Register

Format:

AT [cmds] S35=n [cmds]

Example:

ATS35=2<CR>

Default:

2

Range:

0, 2

Unit:

N/A

Description:

Selects power saving mode.

Command

Function

S35=0

Power saving mode disabled.

í S35=2

Power saving mode enabled.

REDIAL

Type:

Immediate

Format:

ATA:

Example:

ATA:<CR>

Description:

Redials the last number dialed until it is no longer busy.

REMOTE CONNECT SPEED

Type:

Configuration

Format:

AT $MBnnn

Example:

AT $MB9600 $SB19200<CR>

Description:

Sets maximum remote connect speed.

Command

Function

$MB75

Sets V.23 (1200bps/75bps bi-directional).

$MB300

Sets 300bps connect.

$MB1200

Sets 1200bps connect.

$MB2400

Sets 2400bps connect.

$MB4800

Sets 4800bps connect.

$MB9600

Sets 9600bps connect.

$MB14400

Sets 14.4Kbps connect.

$MB19200

Sets 19.2Kbps connect.

$MB28800

Sets 28.8Kbps connect.

RETRANSMIT FAIL ACTION

Type:

Configuration

Format:

AT [cmds] $Rn [cmds]

Example:

AT $R1<CR>

Description:

Sets whether the modem gives up on a bad connection.

Command

Function

í $R0

Hang up after 12 failed retransmissions.

$R1

Do not hang up after 12 failed retransmissions.

STORE PHONE NUMBER IN NVRAM

Type:

Configuration

Format:

AT [cmds] D<#>Nn [dialstring]

Example:

ATD555-1212N1<CR>

Description:

Stores a phone number in the modem’s memory.

TRELLIS MODULATION

Type:

Configuration

Format:

AT [cmds] #Tn [cmds]

Example:

AT #T1<CR>

Description:

Controls Trellis Coded Modulation.

Command

Function

#T0

Disables TCM.

í #T1

Enables TCM.

V.42 MODE

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E0 <CR>

Description:

Configures the operation of V.42 mode.

Command

Function

&E0

Error correction disabled.

í &E1

V.42 set to auto-reliable.

&E2

V.42 set to reliable.

XOFF SEND

Type:

Configuration

Format:

AT [cmds] #Xn [cmds]

Example:

AT #X1<CR>

Description:

Selects how XOFF signal is sent.

Command

Function

í #X0

Single XOFF character sent until ready.

#X1

Multiple XOFF characters sent until ready.

XON/XOFF PASS-THROUGH

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E7 O<CR>

Description:

Selects whether XON/XOFF signals are sent to remote modem.

Command

Function

í &E6

XON/XOFF signals trapped by local modem.

&E7

XON/XOFF passed through local modem.