X.21公头连接器

X.21母头连接器

X.21接口定义
| Pin | Name | DTE I/O | Description | Type |
|---|---|---|---|---|
| 1 | Shield | ![]() | Shield | Ground |
| 2 | T (A) | ![]() | Transmit (A) | Data |
| 3 | C (A) | ![]() | Control (A) | Control |
| 4 | R (A) | ![]() | Receive (A) | Data |
| 5 | I (A) | ![]() | Indication (A) | Control |
| 6 | S (A) | ![]() | Signal Timing (A) | Timing |
| 7 | B (A) / unused | ![]() | Byte Timing (A) or unassigned | Timing |
| 8 | G | ![]() | Ground | Ground |
| 9 | T (B) | ![]() | Transmit (B) | Data |
| 10 | C (B) | ![]() | Control (B) | Control |
| 11 | R (B) | ![]() | Receive (B) | Data |
| 12 | I (B) | ![]() | Indication (B) | Control |
| 13 | S (B) | ![]() | Signal Timing (B) | Timing |
| 14 | B (B) / unused | ![]() | Byte Timing (B) or unassigned | Timing |
| 15 | unused |
| X.21 | X.21 |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 5 |
| 4 | 2 |
| 5 | 3 |
| 6 | 7 |
| 7 | 6 |
| 8 | 8 |
| 9 | 11 |
| 10 | 12 |
| 11 | 9 |
| 12 | 10 |
| 13 | 14 |
| 14 | 13 |
| 15 |