25 PIN D-SUB MALE at the DTE (Computer).
25 PIN D-SUB FEMALE at the DCE (Modem).
| Pin | Name | Direction | Description |
|---|
| 1 | | --- | Shield (paired with 18) |
| 2 | TxD | Output | Transmitted Data (BA) (paired with 14) |
| 3 | RxD | Output | Received Data (BB) (paired with 16) |
| 4 | RTS | Output | Request To Send (CA) (paired with 19) |
| 5 | CTS | Output | Clear To Send (CB) (paired with 13) |
| 6 | DSR | Output | Data Set Ready (CC) (paired with 22) |
| 7 | SGND | --- | Signal Ground (Ground) (paired with 21) |
| 8 | DCD | Output | Data Carrier Detect (CF) (paired with 10) |
| 9 | | Output | Rtrn Receive Sig. Elmnt Timing (DD) (paired with 17) |
| 10 | | Output | Rtrn DCD (CF) (paired with 8) |
| 11 | | Output | Rtrn Transmit Sig. Elmnt Timing (DA) (paired with 24) |
| 12 | | Output | Rtrn Transmit Sig. Elmnt Timing (DB) (paired with 15) |
| 13 | | Output | Rtrn CTS (CB) (paired with 5) |
| 14 | | Output | Rtrn TxD (BA) (paired with 2) |
| 15 | | Output | Transmit Signal Element Timing (DB) (paired with 12) |
| 16 | | Output | Rtrn RxD (BB) (paired with 3) |
| 17 | | Output | Receive Signal Element Timing (DD) (paired with 9) |
| 18 | LL | Output | Local Loopback (LL) (paired with 1) |
| 19 | | Output | Rtrn RTS (CA) (paired with 4) |
| 20 | DTR | Output | Data Terminal Ready (CD) (paired with 23) |
| 21 | RL | Output | Remote Loopback (RL) (paired with 7) |
| 22 | | Output | Rtrn DSR (CC) (paired with 6) |
| 23 | | Output | Rtrn DTR (CD) (paired with 20) |
| 24 | | Output | Transmit Signal Element timing (DA) (paired with 11) |
| 25 | | Output | Test Mode (TM) |
