MULTITECH SYSTEMS, INC.

MT2834PCS/C, MT2834PCS/CI

Modem Type

Data (synchronous/asynchronous)/Fax/Simultaneous voice

Maximum Data Rate

28.8Kbps

Maximum Fax Rate

14.4Kbps

Data Bus

External

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

Multitech MSP

Fax Modulation Protocol

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

Error Correction/Compression

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

CONNECTIONS

Purpose

Location

Purpose

Location

Line in

CN1

Line out

CN2

INTERRUPT SELECTION

IRQ

JP1/A

JP1/B

JP1/C

JP1/D

JP1/E

JP1/F

JP1/G

JP1/H

JP1/I

JP1/J

í 3

Open

Closed

Open

Open

Open

Open

Open

Open

Open

Open

2/9

Closed

Open

Open

Open

Open

Open

Open

Open

Open

Open

4

Open

Open

Closed

Open

Open

Open

Open

Open

Open

Open

5

Open

Open

Open

Closed

Open

Open

Open

Open

Open

Open

7

Open

Open

Open

Open

Closed

Open

Open

Open

Open

Open

10

Open

Open

Open

Open

Open

Closed

Open

Open

Open

Open

11

Open

Open

Open

Open

Open

Open

Closed

Open

Open

Open

12

Open

Open

Open

Open

Open

Open

Open

Closed

Open

Open

14

Open

Open

Open

Open

Open

Open

Open

Open

Closed

Open

16

Open

Open

Open

Open

Open

Open

Open

Open

Open

Closed

BASE I/O ADDRESS SELECTION

Address

SW1/1

SW1/2

SW1/3

SW1/4

SW1/5

SW1/6

SW1/7

100h

Off

On

On

On

On

On

On

200h

On

Off

On

On

On

On

On

300h

Off

Off

On

On

On

On

On

400h

On

On

Off

On

On

On

On

500h

Off

On

Off

On

On

On

On

2E8h (COM4:)

Off

On

Off

Off

Off

On

Off

í 2F8h (COM2:)

Off

Off

Off

Off

Off

On

Off

3D8h

Off

Off

On

Off

Off

Off

Off

3E0h

On

On

Off

Off

Off

Off

Off

3E8h (COM3:)

Off

On

Off

Off

Off

Off

Off

3F0h

On

Off

Off

Off

Off

Off

Off

3F8h (COM1:)

Off

Off

Off

Off

Off

Off

Off

Note: A total of 127 memory base I/O address settings are available. The switches are a binary representation of the hexadecimal addresses. Switch SW1/1 is the Least Significant Bit and switch SW1/7 is the Most Significant Bit. The switches have the following decimal values: switch SW1/1=8, SW1/2=16, SW1/3=32, SW1/4=64, SW1/5=128, SW1/6=256, SW1/7=512.Turn off the switches and add the values of the off switches to obtain the correct base I/O address. (on=0, off=1)

FACTORY CONFIGURED - DO NOT ALTER

Switch

Position

SW1/8

On

Proprietary Command Set

AMBIENT NOISE SENSITIVITY

Type:

Configuration

Format:

AT [cmds] >HVn [cmds]

Example:

AT >HV10 >C0<CR>

Default:

7

Range:

0-14

Description:

Sets the modem’s sensitivity to ambient noise, with 0 being the most sensitive.

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 ATTEMPTS

Type:

Register

Format:

AT [cmds] S16=n [cmds]

Example:

ATS16=6<CR>

Default:

4

Range:

1-255

Unit:

1 attempt

Description:

Sets the maximum number of login attempts after initial callback connection.

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.

DETECTION MODE

Type:

Configuration

Format:

AT [cmds] >DTn [cmds]

Example:

AT >DT1<CR>

Description:

Sets the responses the modem will detect.

Command

Function

í >DT0

Detection disabled.

>DT1

DTMF detection enabled.

>DT2

All signals will be detected.

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.

DSP INPUT

Type:

Configuration

Format:

AT [cmds] >DIn [cmds]

Example:

AT >DI4 >DO6<CR>

Description:

Sets the input source of the digital signal processor.

Command

Function

í >DI0

Input disabled.

>DI1

Input from line in.

>DI2

Input from handset.

>DI3

Input from phone.

>DI4

Input from PC.

>DI5

Input from voicemail.

>DI6

Input from Digital Simultaneous Voice Mode session.

DSP OUTPUT

Type:

Configuration

Format:

AT [cmds] >DOn [cmds]

Example:

AT >DI5 >DO3<CR>

Description:

Sets the output device of the digital signal processor.

Command

Function

í >DO0

Output disabled.

>DO1

Output to line out.

>DO2

Output to handset.

>DO3

Output to phone.

>DO4

Output to PC.

>DO5

Output to voicemail.

>DO6

Output to Digital Simultaneous Voice Mode session.

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.

DSVD TALK ANYTIME™

Type:

Configuration

Format:

AT [cmds] >Cn [cmds]

Example:

AT >C1 O<CR>

Description:

Enables DSVD (Digital Simultaneous Voice Data) connection.

Command

Function

í >C0

Talk Anytime™ enabled.

>C1

Talk Anytime™ disabled.

DSVD

Type:

Immediate

Format:

AT [cmds] >VDn [cmds]

Example:

AT >VD1 O<CR>

Description:

Activates DSVD (Digital Simultaneous Voice Data) connection.

Command

Function

í >VD0

Deactivates DSVD.

>VD1

Activates DSVD.

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.

FAILED PASSWORD ATTEMPTS

Type:

Register

Format:

AT [cmds] S26?

Example:

ATS26?<CR>

Default:

Read-only

Range:

0-255

Unit:

1 attempt

Description:

This register stores the number of failed password attempts.

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, 21.6Kbps, 19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps, 4800bps, 2400bps, 1200bps, 300bps.

#A1

Attempts only 28.8Kbps.

#A2

Attempts in order: 28.8Kbps, 24Kbps, 21.6Kbps, 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.

LINE CONNECTION

Type:

Configuration

Format:

AT [cmds] >PHn [cmds]

Example:

AT >PH1<CR>

Description:

Selects the operation mode of the modem.

Command

Function

í >PH0

Modem is in data mode.

>PH1

Modem is in voice mode.

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.

MICROPHONE

Type:

Configuration

Format:

AT [cmds] >Mn>MVn [cmds]

Example:

AT >M2>MV5<CR>

Description:

Turns the microphone of the attached telephone handset on or off.

Note:

An >MV command must be issued on the same line.

Command

Function

>M0

Disables microphone.

í >M2

Enables microphone.

MICROPHONE SENSITIVITY

Type:

Configuration

Format:

AT [cmds] >MVn [cmds]

Example:

AT >MV6<CR>

Default:

None

Range:

0-14

Description:

Sets the microphone’s sensitivity, with 0 being the most sensitive.

MSP MODE

Type:

Configuration

Format:

AT [cmds] >%Pn [cmds]

Example:

AT >%P1<CR>

Description:

Enables or disables Multitech Supervisory Protocol (MSP).

Command

Function

í %P0

MSP disabled.

%P1

MSP enabled.

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.

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.

SETUP INACTIVITY TIMER

Type:

Register

Format:

AT [cmds] S29=n [cmds]

Example:

ATS29=5<CR>

Default:

20

Range:

1-255

Unit:

1 minute

Description:

Sets the maximum amount of time between commands until the setup password must be re-entered.

SPEAKER

Type:

Configuration

Format:

AT [cmds] >Sn>SVn [cmds]

Example:

AT >S2>SV5<CR>

Description:

Turns the speaker of the attached telephone handset on or off.

Note:

An >SV command must be issued on the same line.

Command

Function

>S0

Disables speaker.

í >S2

Enables speaker.

SPEAKER VOLUME

Type:

Configuration

Format:

AT [cmds] >SVn [cmds]

Example:

AT >SV6<CR>

Default:

None

Range:

0-14

Description:

Sets the speaker’s volume, with 0 being the most sensitive.

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.

TIME UNTIL HANG UP ON LOW DTR

Type:

Register

Format:

AT [cmds] S36=n [cmds]

Example:

ATS36=5<CR>

Default:

0

Range:

0-255

Unit:

1 second

Description:

Sets the maximum amount of time the modem will wait to hang up after the DTR signal goes low.

TIME UNTIL PICK UP ON HIGH DTR

Type:

Register

Format:

AT [cmds] S37=n [cmds]

Example:

ATS37=5<CR>

Default:

0

Range:

0-255

Unit:

1 second

Description:

Sets the maximum amount of time the modem will wait to pick up after the DTR signal goes high.

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.32terbo CONTROL

Type:

Configuration

Format:

AT [cmds] #Vn [cmds]

Example:

AT #V1 DT555-1212<CR>

Description:

Controls the V.32terbo protocol in answer mode.

Command

Function

í #V0

V.32terbo enabled.

#V1

V.32terbo disabled.

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.

VOICE BANDWIDTH

Type:

Configuration

Format:

AT [cmds] >An [cmds]

Example:

AT >A0 <CR>

Description:

Sets the bandwidth reserved for voice transmission.

Command

Function

>A0

Voice bandwidth set to 9600bps.

>A1

Voice bandwidth set to 16Kbps.

í >A2

Voice bandwidth set to 16Kbps if connected at 19.2Kbps or above, or 9600bps otherwise.

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.