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. |