MULTI-TECH SYSTEMS, INC.

MT224EH/MT224EHI

Modem Type

Data (synchronous/asynchronous)

Maximum Data Rate

2400bps

Data Bus

External

Data Modulation Protocol

Bell 103A/212A

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

Error Correction/Compression

MNP5

CONNECTIONS

Purpose

Location

Purpose

Location

DC power

CN1

Line in

CN4

RS-232/422

CN2

Power switch

SW1

Line out

CN3

Volume

R1

ASYNCHRONOUS/SYNCHRONOUS

Settings

SW5/D

Synchronous

On

» Asynchronous

Off

AUTO-ANSWER

Settings

SW4/E

» Enable auto answer/originate

On

Disable/answer

Off

Note: When SW5/B is set for Lease Line operation, the options on this switch change to Originate and Answer

BLIND/WAIT DIALING

Settings

SW5/C

» Blind dialing

Off

Wait for dial tone

On

BAUD RATE

Settings

SW2

1200bps

Position 1

300bps

Position 2

2400bps

Position 3

CD/DSR

Settings

SW4/F

» CD/DSR normal

On

CD/DSR forced high

Off

COMMAND CHARACTERS

Settings

SW4/D

» Echo enable

On

Echo disable

Off

COMMAND MODE

Settings

SW4/H

» Enable

Off

Disable

On

CTS

Settings

SW5/A

» CTS forced high

On

CTS normal

Off

CTS/RTS

Settings

JP2

» CTS follows RTS

Pins 1 & 2 closed

CTS forced high until disconnect

Pins 2 & 3 closed

DSR

Settings

JP3

» DSR follows CD

Pins 2 & 3 closed

DSR follows OH

Pins 1 & 2 closed

FORCED DTR

Settings

SW4/A

» DTR forced high

Off

DTR normal

On

JACK TYPE

Settings

SW4/G

» RJ11

On

RJ12/13

Off

RESULT CODES

Settings

SW4/B

» Verbose

On

Terse

Off

RESULT CODES

Settings

SW4/C

» Enable

Off

Disable

On

RTS

Settings

JP1

» RTS forced high

Pins 1 & 2 closed

RTS normal

Pins 2 & 3 closed

SWITCHED/LEASE LINE

Settings

SW5/B

» Switched

On

Lease line

Off

VOICE/DATA MODE

Settings

SW3

Answer

Position 1

Originate

Position 2

DIAGNOSTIC LED(S)

LED

Color

Status

Condition

SD

Red

On

Modem is transmitting data

SD

Red

Off

Modem is not transmitting data

RD

Red

On

Modem is receiving data

RD

Red

Off

Modem is not receiving data

CD

Red

On

Carrier signal detected

CD

Red

Off

Carrier signal not detected

24

Red

Blinking fast

Modem connected at 2400bps in reliable mode

24

Red

Blinking slow

Modem connected at 2400bps with data compression

24

Red

Off

Modem not connected at 2400bps

12

Red

Blinking fast

Modem connected at 1200bps in reliable mode

12

Red

Blinking slow

Modem connected at 1200bps with data compression

12

Red

Off

Modem not connected at 1200bps

OH

Red

On

Modem is off-hook

OH

Red

Off

Modem is on-hook

TR

Red

On

DTR signal is high

TR

Red

Off

DTR signal is low

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

» $AO

Data is discarded.

$A1

Data is buffered.

BLIND DIALING

Type:

Configuration

Format:

AT [cmds] Bn [cmds]

Example:

AT B0 <CR>

Description:

Selects blind dial or wait-for-dial-tone.

Command

Function

» B0

Modem will blind dial.

B1

Modem will wait for dial tone before dialing.

BUFFER SIZE

Type:

Configuration

Format:

AT [cmds] &Bn [cmds]

Example:

AT &B0<CR>

Description:

Selects the modem’s transmit/receive buffer size.

Command

Function

» &B0

Normal buffer size.

&B1

Small buffer size.

CD SIGNAL

Type:

Configuration

Format:

AT [cmds] &Cn [cmds]

Example:

AT &C3 $D0<CR>

Description:

Configures the behavior of the carrier detect signal.

Command

Function

&C0

CD forced high.

» &C1

CD normal.

&C2

CD forced high except during disconnect.

COMMAND SET

Type:

Configuration

Format:

AT [cmds] &Qn [cmds]

Example:

AT &Q0<CR>

Description:

Selects standard Hayes or custom command sets.

Command

Function

» &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.

» &E15

Data compression enabled.

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/CTS/CD 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 DSR, CTS, and CD signals to hangup.

DTR DIALING

Type:

Configuration

Format:

AT [cmds] $Dn [cmds]

Example:

AT $D1 DT555-1212<CR>

Description:

Selects the DTR dialing function.

Command

Function

» $D0

DTR dialing disabled.

$D1

DTR dialing enabled.

DTR TIMEOUT

Type:

Register

Format:

AT [cmds] S25=n [cmds]

Example:

ATS25=30<CR>

Default:

0

Range:

0-255

Unit:

.1 second

Description:

Sets the time to drop the DTR signal to hangup.

Note:

Setting S25 to 0 sets the DTR timeout to 50 ms.

DUPLEX

Type:

Configuration

Format:

AT [cmds] Fn [cmds]

Example:

AT F1 &W<CR>

Description:

Controls duplex mode.

Command

Function

F0

Half duplex enabled.

» F1

Full duplex enabled.

FACTORY DEFAULTS

Type:

Immediate

Format:

AT &F

Example:

AT &F<CR>

Description:

Loads factory defaults from ROM and DIP-switches.

FLOW CONTROL

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E13<CR>

Description:

Selects flow control.

Command

Function

&E12

Flow control disabled.

» &E13

Flow control enabled.

FLOW CONTROL - ENQ/ACK

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E8<CR>

Description:

Selects ENQ/ACK pacing.

Command

Function

» &E8

Disables ENQ/ACK pacing.

&E9

Enables ENQ/ACK pacing.

FLOW CONTROL IN NORMAL MODE

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E11 O<CR>

Description:

Selects XON/XOFF flow control for non-error-correcting connections.

Command

Function

» &E10

XON/XOFF disabled for non-error-correcting connections.

&E11

XON/XOFF enabled for non-error-correcting connections.

FLOW CONTROL TYPE

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E3 &W<CR>

Description:

Sets type of flow control used by modem.

Command

Function

» &E3

Flow control disabled.

&E4

CTS/RTS flow control enabled.

&E5

XON/XOFF flow control enabled.

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.

$H4

Shows help screen 4.

INACTIVITY TIMER

Type:

Configuration

Format:

AT [cmds] &In [cmds]

Example:

AT &I5 S30=40<CR>

Description:

Sets the length of time that the modem does not receive information before it disconnects.

Command

Function

» &I0

Inactivity timer disabled.

&I1

Modem will disconnect after 10 minutes of inactivity.

&I2

Modem will disconnect after 30 minutes of inactivity.

&I3

Modem will disconnect after 60 minutes of inactivity.

LIST CONFIGURATION

Type:

Immediate

Format:

AT Ln

Example:

AT L5<CR>

Description:

Lists modem configuration.

Command

Function

L0

Lists all phone numbers in memory.

L5

Lists all settings.

L6

Lists the values of all S-registers.

L7

Lists extended parameters.

LOCAL SERIAL PORT SPEED

Type:

Configuration

Format:

AT [cmds] $SBnnn [cmds]

Example:

AT $MB9600 $SB19200<CR>

Description:

Sets serial port speed.

Command

Function

$SB110

Sets 110bps speed.

$SB300

Sets 300bps speed.

$SB1200

Sets 1200bps speed.

» $SB2400

Sets 2400bps speed.

$SB4800

Sets 4800bps speed.

$SB9600

Sets 9600bps 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

» $BA0

Serial speed locked at rate set by $SB.

$BA1

Serial speed follows connect speed, ignoring $SB.

LOOPBACK TEST MODE

Type:

Configuration

Format:

AT [cmds] Un [cmds]

Example:

AT U2 &W<CR>

Description:

Places modem in test mode.

Command

Function

U0

Begin local analog loopback test in originate mode.

U1

Begin local analog loopback test in answer mode.

U2

Request remote digital loopback

U3

Begin local digital loopback.

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.

» &BS1

Maximum block size is 256 characters.

PROTOCOL

Type:

Configuration

Format:

AT [cmds] &Vn [cmds]

Example:

AT &V1 <CR>

Description:

Selects the protocol for low-speed data calls.

Command

Function

&V0

Bell protocols.

» &V1

ITU-T protocols.

REDIAL

Type:

Immediate

Format:

A:

Example:

A:

Description:

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

Note:

Do not precede this command with AT or follow it with <CR>.

REMOTE CONNECT SPEED

Type:

Configuration

Format:

AT $MBnnn

Example:

AT $MB2400 $SB19200<CR>

Description:

Sets maximum remote connect speed.

Command

Function

$MB75

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

$MB110

Sets 110bps connect.

$MB300

Sets 300bps connect.

$MB1200

Sets 1200bps connect.

» $MB2400

Sets 2400bps 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

» $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<#>N<0-9>

Example:

ATD1(303)-443-3323N6 <CR>

Description:

Stores a phone number in the modem’s memory. Only the dialstring before the Nn will be stored.

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.

&E1

V.42 set to auto-reliable.

&E2

V.42 set to reliable.

WAIT FOR DIAL TONE

Type:

Immediate

Format:

AT [cmds] W [cmds]

Example:

AT W <CR>

Description:

Wait for new dial tone.

XON/XOFF PASS-THROUGH

Type:

Configuration

Format:

AT [cmds] &En [cmds]

Example:

AT &E6 <CR>

Description:

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

Command

Function

» &E6

XON/XOFF signals trapped by local modem.

&E7

XON/XOFF passed through local modem.