VEN-TEL, INC.
PCM-XT24A
| Modem Type | Data (synchronous/asynchronous) |
| Maximum Data Rate | 2400bps |
| Data Bus | 8-bit ISA |
| Data Modulation Protocol | Bell 103A/212A ITU-T V.21, V.22, V.22bis |
| Error Correction/Compression | N/A |
CONNECTIONS |
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Purpose |
Location |
Purpose |
Location |
| Line in | CN1 |
Line out | CN2 |
XT SLOT 8 |
|
Selection |
SW1/1 |
Board is not installed in slot 8 of an XT |
Off |
Board is installed in slot 8 of an XT |
On |
BASE I/O ADDRESS SELECTION |
|||
Address |
SW1/3 |
SW1/4 |
|
| » | COM2: (2F8h) |
Off |
Off |
COM1: (3F8h) |
On |
Off |
|
COM3: (3E8h) |
On |
On |
|
COM4: (2E8h) |
Off |
On |
|
INTERRUPT SELECTION |
|||
IRQ |
JP1 |
JP2 |
|
| » | 3 |
Open |
Closed |
4 |
Closed |
Open |
|
FACTORY CONFIGURED - DO NOT ALTER |
|
Switch |
Position |
SW1/2 |
Off |
Proprietary Command Set
BIT-MAPPED REGISTER |
|||
| Format | AT [cmds] S14= n [cmds] | ||
| Example: | AT S14=139 <CR> | ||
| Default: | 170 | ||
| Range: | 0 - 175 | ||
| Unit: | Bit-mapped | ||
| Description: | Controls echo, quiet mode, result codes, dial mode, and originate/answer mode. | ||
Bit |
Value |
Function |
|
0 |
1 |
Not used. | |
| » | 1 |
0 1 |
Command echo
function disabled. Command echo function enabled. |
| » | 2 |
0 1 |
Result codes
enabled. Result codes disabled. |
| » | 3 |
0 1 |
Numeric format
enabled. Verbose format enabled. |
4 |
0 |
Not used. | |
| » | 5 |
0 1 |
Tone dialing mode
enabled. Pulse dialing mode enabled. |
6 |
0 |
Not used. | |
| » | 7 |
0 1 |
Answer mode
enabled. Originate mode enabled. |
BIT-MAPPED REGISTER |
|||
| Format | AT [cmds] S21= n [cmds] | ||
| Example: | AT S21=1 <CR> | ||
| Default: | 0 | ||
| Range: | 0 - 184 | ||
| Unit: | Bit-mapped | ||
| Description: | Controls low DTR action, DCD signal, and the Long Space Disconnect function. | ||
Bit |
Value |
Function |
|
0 |
0 |
Not used. | |
1 |
0 |
Not used. | |
2 |
0 |
Not used. | |
| » | 4, 3 |
00 01 10 11 |
DTR signal
ignored. Modem goes to command mode on low DTR. Modem disconnects on low DTR. Auto-Answer is disabled. Modem is initialized on low DTR. |
| » | 5 |
0 1 |
DCD signal forced
high. DCD signal normal. |
6 |
0 |
Not used. | |
| » | 7 |
0 1 |
Long Space
Disconnect function disabled. Long Space Disconnect function enabled. |
BIT-MAPPED REGISTER |
|||
| Format | AT [cmds] S22= n [cmds] | ||
| Example: | AT S22=114 <CR> | ||
| Default: | 116 | ||
| Range: | 0 - 252 | ||
| Unit: | Bit-mapped | ||
| Description: | Controls volume and speaker settings, result codes, and make/break pulse ratio. | ||
Bit |
Value |
Function |
|
0 |
0 |
Not used. | |
1 |
0 |
Not used. | |
| » | 3, 2 |
00 01 10 11 |
Speaker disabled.
Speaker enabled until carrier signal detected Speaker enabled. Speaker enabled following dialing, then disabled after carrier signal detected. |
| » | 6, 5 ,4 |
000 100 101 110 111 |
Busy and dialtone
detection disabled, result codes 0-4 enabled. Busy and dialtone detection disabled, result codes 0-5, 10 enabled. Busy tone detection disabled, dialtone detection enabled, result codes 0-6, 10 enabled. Busy tone detection enabled, dialtone detection disabled, result codes 0-5, 7, 10 enabled. Busy and dialtone detection enabled, result codes 0-7, 10 enabled. |
| » | 7 |
0 1 |
39/61ms at 10pps
(North America) 33/67ms at 10pps (Europe) |
BIT-MAPPED REGISTER |
|||
| Format | AT [cmds] S23= n [cmds] | ||
| Example: | AT S23=114 <CR> | ||
| Default: | 0, read-only (see note) | ||
| Range: | 0 - 255 | ||
| Unit: | Bit-mapped | ||
| Description: | Controls guard tones. Also indicates speed and parity. Also provides storage for remote digital loopback tests. | ||
| Note: | All bits except bits 6 and 7 are read-only. | ||
Bit |
Value |
Function |
|
| » | 0 |
0 1 |
RDL response
disabled. RDL response enabled. |
2, 1 |
00 01 10 11 |
Select 300bps
speed. Select 600bps speed. Select 1200bps speed. Select 2400bps speed. |
|
3 |
0 |
Not used. | |
5, 4 |
00 01 10 11 |
Select Even
parity bit. Select Space parity bit. Select Odd parity bit. Select no (Mark) parity bit. |
|
| » | 7, 6 |
00 01 10 |
Guard tone
disabled. 550Hz guard tone enabled. 1800Hz guard tone enabled. |
PROTOCOL TYPE |
||
| Type: | Register | |
| Format: | AT [cmds] S27= n [cmds] | |
| Example: | AT S27=0 <CR> | |
| Description: | Selects the protocols used.. | |
Command |
Function |
|
| » | S27=0 |
CCITT protocols selected. |
S27=64 |
Bell protocols selected. | |
LOOPBACK TESTS |
|||
| Format | AT [cmds] S16= n [cmds] | ||
| Example: | AT S16=32 <CR> | ||
| Default: | 0 | ||
| Range: | 0 - 255 | ||
| Unit: | Bit-mapped | ||
| Description: | Enables loopback tests. | ||
| Note: | Bit 3 is read-only. | ||
Bit |
Value |
Function |
|
| » | 0 |
0 1 |
Local analog
loopback test disabled. Local analog loopback test enabled. |
1 |
0 |
Not used. | |
| » | 2 |
0 1 |
Local digital
loopback test disabled. Local digital loopback test enabled. |
| » | 3 |
0 1 |
Modem is not
performing remote digital loopback test. Modem is performing remote digital loopback test. |
| » | 4 |
0 1 |
Remote digital
loopback test disabled. Remote digital loopback test enabled. |
| » | 5 |
0 1 |
Remote digital
loopback with local self-test disabled. Remote digital loopback with local self-test enabled. |
| » | 6 |
0 1 |
Local analog
loopback with local self-test disabled. Local analog loopback with local self-test enabled. |
7 |
0 |
Not used. | |