3COM CORPORATION
COURIER HST DUAL STANDARD W/ V.32BIS & ASL
Modem Type | Data (synchronous/asynchronous) |
Maximum Data Rate | 14.4Kbps |
Data Bus | External |
Data Modulation Protocol | Bell 103A/212A ITU-T V.22, V.22bis, V.23, V.32, V.32bis |
Error Correction/Compression | MNP5, V.42, V.42bis |

CONNECTIONS | |||
Purpose | Location | Purpose | Location |
Line out | CN1 | DC power | CN4 |
Line in | CN2 | Volume | R1 |
RS-232/422 | CN3 | Power switch | SW2 |
MI/MIC POLARITY | ||
| Setting | J6 | J8 |
| » Normal | Pins 1 & 2 closed | Pins 1 & 2 closed |
| Reversed | Pins 2 & 3 closed | Pins 2 & 3 closed |
TX/RX PIN ASSIGNMENT | |
| Setting | SW3 |
Normal operation | » Off |
Reverse TX/RX pin assignments | On |
DTR SIGNAL | |
| Setting | SW1/1 |
| DTR forced high | On |
| » DTR normal | Off |
RESULT CODES | |
| Setting | SW1/2 |
| » Verbose result codes enabled | Off |
| Numeric result codes enabled | On |
RESULT CODES DISPLAY | |
| Setting | SW1/3 |
| » Display enabled | On |
| Display disabled | Off |
ECHO COMMANDS DISPLAY | |
| Setting | SW1/4 |
| » Local echo enabled | Off |
| Local echo disabled | On |
AUTO ANSWER | |
| Setting | SW1/5 |
| » Modem answers on first ring | On |
| Modem does not answer on first ring | Off |
CARRIER DETECT | |
| Setting | SW1/6 |
| » CD normal | Off |
| CD forced high | On |
RESULT CODES DISPLAY | |
| Setting | SW1/7 |
| » Display result codes in originate and answer modes | Off |
| Display result codes in Answer mode | On |
AT COMMAND SET | |
| Setting | SW1/8 |
| » AT command set enabled | On |
| AT command set disabled | Off |
ESCAPE CODE | |
| Setting | SW1/9 |
| » Off | Disconnect, go to command mode and display NO CARRIER when escape character is received |
| On | Go to command mode and display OK result code when escape character is received |
USER PROFILE | |
| Setting | SW1/10 |
| » Off | Use stored profile |
| On | Use factory default |
VOICE/DATA | |
Setting | SW4 |
Note: for switch functions see table for register S32. | |
DIAGNOSTIC LED(S) | |||
LED | Color | Status | Condition |
HS | Red | On | Modem is operating at 4800bps or faster |
HS | Red | Off | Modem is operating at slower than 4800bps |
AA | Red | On | Auto-answer enabled |
AA | Red | Off | Auto-answer disabled |
CD | Red | On | Carrier signal detected |
CD | Red | Off | Carrier signal not detected |
OH | Red | On | Modem is off-hook |
OH | Red | Off | Modem is on-hook |
RD | Red | On | Modem is receiving data |
RD | Red | Off | Modem is not receiving data |
TD | Red | On | Modem is transmitting data |
TD | Red | Off | Modem is not transmitting data |
TR | Red | On | DTR signal is high |
TR | Red | Off | DTR signal is low |
MR | Red | On | Power is on |
MR | Red | Off | Power is off |
MR | Red | Blinking | Modem is retraining or in test mode |
RS | Red | On | RTS signal is high |
RS | Red | Off | RTS signal is low |
CS | Red | On | CTS signal is high |
CS | Red | Off | CTS signal is low |
EC | Red | On | Error control enabled |
EC | Red | Off | Error control disabled |
EC | Red | Blinking | Modem is retransmitting data |
SYN | Red | On | Synchronous mode |
SYN | Red | Off | Asynchronous mode |
Proprietary AT Command Set
BIT-MAPPED REGISTER S13 | |||
Format | AT [cmds] S13=n [cmds] | ||
Example: | ATS13=139 <CR> | ||
Default: | 0 | ||
Range: | 0 - 255 | ||
Unit: | Bit-mapped | ||
Description: | Controls DTR reset, DTR dialing, auto answer, result code delay, reset dialing, HST and MNP3. | ||
Bit | Value | Function | |
0 | » 0 1 | DTR normal. Reset on low DTR. | |
1 | » 0 1 | Auto answer operation normal. When ring detected, enter originate mode and listen for answer tone. | |
2 | » 0 1 | Pause 250 msec. before displaying result codes. Display result codes immediately. | |
3 | » 0 1 | DTR dialing disabled. DTR dialing enabled. | |
4 | » 0 1 | Reset dialing disabled. Reset dialing enabled. | |
5 | » 0 1 | HST enabled. HST disabled. | |
6 | » 0 1 | MNP 3 enabled. MNP 3 disabled. | |
BIT-MAPPED REGISTER S15 | |||
Format: | AT [cmds] S15=n [cmds] | ||
Example: | ATS15=139 <CR> | ||
Default: | 0 | ||
Range: | 0 - 255 | ||
Unit: | Bit-mapped | ||
Description: | Controls HST high frequency equalization, online fallback, back channel, non-error-correcting mode buffer, MNP4, BS/DEL switch, and MNP compliance. | ||
Bit | Value | Function | |
0 | » 0 1 | HST high frequency equalization enabled. HST high frequency equalization disabled. | |
1 | » 0 1 | Online fallback enabled. Online fallback disabled. | |
2 | » 0 1 | 450bps back channel enabled. 450bps back channel disabled. | |
3 | » 0 1 | Non-error-correcting mode transmit buffer set to 1.5KB. Non-error-correcting mode transmit buffer set to 128 bytes. | |
4 | » 0 1 | MNP 4 enabled. MNP 4 disabled. | |
5 | » 0 1 | Use backspace key for delete disabled. Use backspace key for delete enabled. | |
6 | » 0 1 | MNP normal. MNP adjusted for non compliant modems. | |
7 | » 0 1 | Proprietary network compatibility disabled. Proprietary network compatibility enabled. | |
BIT-MAPPED REGISTER S27 | |||
Format: | AT [cmds] S27=n [cmds] | ||
Example: | ATS27=139 <CR> | ||
Default: | 0 | ||
Range: | 0 - 191 | ||
Unit: | Bit-mapped | ||
Description: | Controls V.21, V.32 encoding and modulation, V.42 answer tone and handshake, and 9600 result codes. | ||
Bit | Value | Function | |
0 | » 0 1 | V.21 disabled. V.21 enabled. | |
1 | » 0 1 | V.32 trellis coding disabled. V.32 trellis coding enabled. | |
2 | » 0 1 | V.32 modulation enabled. V.32 modulation disabled. | |
3 | » 0 1 | 2100Hz answer tone enabled. 2100Hz answer tone disabled. | |
5, 4 | » 00 01 10 11 | V.42 detect, LAPM and MNP enabled. V.42 detect and LAPM enabled. MNP enabled. LAPM enabled. | |
6 | » 0 | Not used. | |
7 | » 0 1 | Actual result codes displayed. Force 9600 result codes. | |
BREAK LENGTH | |
Type: | Register |
Format: | AT [cmds] S21=n [cmds] |
Example: | ATS21=20 <CR> |
Default: | 10 |
Range: | Unidentified |
Unit: | 10 ms |
Description: | Sets the length of error control mode breaks sent from DCE to DTE. |
BREAK TYPE | |
Type: | Configuration |
Format: | AT [cmds] &Yn [cmds] |
Example: | AT &Y0 <CR> |
Description: | Configures action of break signal. |
| Command | Function |
| &Y0 | Break empties buffer. |
| » &Y1 | Break empties buffer and is sent immediately. |
| &Y2 | Break does not empty buffer and is sent immediately. |
COMPRESSION | |
Type: | Configuration |
Format: | AT [cmds] &Kn [cmds] |
Example: | AT &K1 <CR> |
Description: | Controls data compression. |
| Command | Function |
| &K0 | Data compression disabled. |
| » &K1 | Data compression disabled when serial port is locked. |
| &K2 | MNP5 enabled/MNP4 enabled. |
| &K3 | MNP 5 disabled. |
CONNECTION SPEED UPPER LIMIT | |
Type: | Configuration |
Format: | AT [cmds] &Nn [cmds] |
Example: | AT &N1 DT555-1212 <CR> |
Description: | Sets required connection speed if &U is set to 0. Otherwise, sets fastest allowed connection speed. |
| Command | Function |
| » &N0 | Variable. |
| &N1 | 300bps |
| &N2 | 1200bps |
| &N3 | 2400bps |
| &N4 | 4800bps |
| &N5 | 7200bps |
| &N6 | 9600bps |
| &N7 | 12Kbps |
| &N8 | 14.4Kbps |
EXTENDED RESULT CODES | |
Type: | Configuration |
Format: | AT [cmds] &An [cmds] |
Example: | AT &A1 %C1 <CR> |
Description: | Selects extended result codes. |
| Command | Function |
| &A0 | Extended result codes disabled. |
| &A1 | ARQ result codes enabled. |
| &A2 | V.32 result code enabled. |
| » &A3 | Error control and compression result codes enabled. |
FLOW CONTROL CHARACTER - XON | |
Type: | Register |
Format: | AT [cmds] S22=n [cmds] |
Example: | ATS22=20 <CR> |
Default: | 17 |
Range: | 11-127 |
Unit: | ASCII |
Description: | Sets the character used to represent XON. |
FLOW CONTROL CHARACTER - XOFF | |
Type: | Register |
Format: | AT [cmds] S23=n [cmds] |
Example: | ATS23=20 <CR> |
Default: | 19 |
Range: | 11-127 |
Unit: | ASCII |
Description: | Sets the character used to represent XOFF. |
FLOW CONTROL PASSTHROUGH | |
Type: | Configuration |
Format: | AT [cmds] &In [cmds] |
Example: | AT &I0 &W <CR> |
Description: | Allows modem to act on, then transmit XON/XOFF characters. |
| Command | Function |
| » &I0 | Software flow control disabled. |
| &I1 | XON/XOFF passthrough enabled. |
| &I2 | XON/XOFF passthrough disabled. |
| &I3 | ENQ/ACK protocol used in host mode. |
| &I4 | ENQ/ACK protocol used in terminal mode. |
| &I5 | XON/XOFF passthrough disabled in ARQ mode, XON/XOFF to remote modem. |
FLOW CONTROL TYPE | |
Type: | Configuration |
Format: | AT [cmds] &Hn [cmds] |
Example: | AT &H0 A <CR> |
Description: | Sets type of flow control used by modem. |
| Command | Function |
| &H0 | Flow control disabled. |
| » &H1 | CTS/RTS flow control enabled. |
| &H2 | XON/XOFF flow control enabled. |
| &H3 | CTS/RTS and XON/XOFF flow control enabled. |
HELP SCREENS | |
Type: | Immediate |
Format: | AT <prefix>$ |
Example: | AT &$ <CR> |
Description: | Shows command help screens for all commands beginning with the given prefix, or no prefix if none is given. |
Command | Function |
$ | Shows AT help screen. |
&$ | Shows AT& help screen. |
D$ | Shows ATD help screen. |
S$ | Shows S-register help screen. |
INACTIVITY TIMER | |
Type: | Register |
Format: | AT [cmds] S19=n [cmds] |
Example: | ATS19=20 <CR> |
Default: | 0 |
Range: | Unidentified |
Unit: | 1 minute |
Description: | Sets the length of time that the modem does not receive information before it disconnects. |
NETWORK ACCESS | |
Type: | Configuration |
Format: | AT [cmds] %Rn [cmds] |
Example: | AT %R1 &W <CR> |
Description: | Used with USR network management system. |
| Command | Function |
| » %R0 | Network access disabled. |
| %R1 | Network access enabled. |
REPEAT COMMAND STRING | |
Type: | Configuration |
Format: | AT [cmds] > [cmds] |
Example: | AT *D1 > #E1 <CR> |
Description: | Causes modem to repeat command string until a keyboard key is pressed. |
REPORT INFORMATION | |
Type: | Immediate |
Format: | AT [cmds] In [cmds] |
Example: | AT I1 O <CR> |
Description: | Displays modem properties. |
Command | Function |
I0 | Reports product code. |
I1 | Reports ROM checksum result. |
I2 | Reports RAM checksum result. |
I3 | Reports call duration. |
I4 | Reports current command settings. |
I5 | Reports current NVRAM settings. |
I6 | Reports current connection’s statistics. |
I7 | Reports configuration. |
STATUS REGISTER BIT | |
Type: | Configuration |
Format: | Read: AT [cmds] Sn.m=0 or 1 [cmds] Write: AT [cmds] Sn.m=? [cmds] |
Example: | AT S40.4=1 S51.3? <CR> |
Description: | Sets/clears or reads bit m of register n. |
TEST MODES | |||
Format | AT [cmds] S16=n [cmds] | ||
Example: | ATS16=32 <CR> | ||
Default: | 0 | ||
Range: | 0 - 15 | ||
Unit: | Bit-mapped | ||
Description: | Enables loopback tests. | ||
Bit | Value | Function | |
0 | » 0 1 | Analog loopback test disabled. Analog loopback test enabled. | |
1 | » 0 1 | Dial test disabled. Dial test enabled. | |
2 | » 0 1 | Test pattern disabled. Test pattern enabled. | |
3. | » 0 1 | Remote digital loopback test disabled. Remote digital loopback test enabled. | |
TIME DISPLAY | |
Type: | Immediate |
Format: | AT [cmds] Kn [cmds] |
Example: | AT K1 *L2 #E1<CR> |
Description: | Displays the current call time or clock time. |
| Command | Function |
| » K0 | Display length of last call. |
| K1 | Display actual time. |
TOUCH TONE RECOGNITION | |
Type: | Configuration |
Format: | AT [cmds] %Tn [cmds] |
Example: | AT %T &W <CR> |
Description: | Controls recognition of touch tones while off hook. |
V.32 AND V.32bis MODULATIONS | |||
Format: | AT [cmds] S34=n [cmds] | ||
Example: | ATS34=139 <CR> | ||
Default: | 6 | ||
Range: | 0 - 63 | ||
Unit: | Bit-mapped | ||
Description: | Controls V.32 and V.32bis modulations. | ||
Bit | Value | Function | |
0 | » 0 1 | V.32bis enabled. V.32bis disabled. | |
1 | » 0 1 | Enhanced V.32bis enabled. Enhanced V.32bis disabled. | |
2 | » 0 1 | Enhanced V.32bis retrain enabled. Enhanced V.32bis retrain disabled. | |
3 | » 0 1 | V.23 disabled. V.23 enabled. | |
4 | » 0 1 | MR LED normal. MR LED reflects DSR signal. | |
5 | » 0 1 | MI/MIC disabled. MI/MIC enabled. | |
V.32 HANDSHAKE TIME | |
Type: | Register |
Format: | AT [cmds] S28=n [cmds] |
Example: | ATS28=20 <CR> |
Default: | 8 |
Range: | 0-255 |
Unit: | .1 second |
Description: | Sets length of V.32 handshake. |
VOICE/DATA SWITCH | |
Type: | Register |
Format: | AT [cmds] S32=n [cmds] |
Example: | ATS32=6 <CR> |
Default: | 1 |
Unit: | 1-7 |
Description: | Controls the function of SW4. |
| Command | Function |
| 0 | Disabled. |
| » 1 | Switch between voice and originate mode. |
| 2 | Switch between voice and answer mode. |
| 3 | Redial. |
| 4 | Dial number stored at position 0. |
| 5 | Enable and disable Auto Answer. |
| 6 | Reset. |
| 7 | Start remote digital loopback test. |