| Baytech RPC-3 EIA-232 connector Pin Name | Baytech RPC-3 EIA-232 connector Pin Number | Direction | PC serial port Pin Number | PC serial port Pin Name | Description |
| rpc-3 TX | 4 | --> | 2 | pc RX | |
| rpc-3 RX | 5 | <-- | 3 | pc TX | |
| rpc-3 RTS | 3 | --> | 8 | pc CTS | |
| rpc-3 DTR | 1 | --> | 6 | pc DSR | |
| GND | 2 | --- | 5 | GND | |
| rpc-3 CD | 8 | <-- | 1 | CP |

