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MT224AH

MULTI-TECH SYSTEMS, INC.

MT224AH

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, V.42, V.42bis

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

Wait for dial tone

On

» Blind dialing

Off

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

Disable

On

» Enable

Off

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 normal

On

» DTR forced high

Off

JACK TYPE

Settings

SW4/G

» RJ11

On

RJ12/13

Off

RESULT CODES

Settings

SW4/B

» Verbose

On

Terse

Off

RESULT CODES

Settings

SW4/C

Disable

On

» Enable

Off

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

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.

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.

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.

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.

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.

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.

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>.

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 N will be stored.

WAIT FOR DIAL TONE

Type:

Immediate

Format:

AT [cmds] W [cmds]

Example:

AT W <CR>

Description:

Wait for new dial tone.