| Pin | RS-232 | RS-422/485 |
|---|---|---|
| 1 | CD (in) | . |
| 2 | RX (in) | B Tx and Half Duplex Rx |
| 3 | TX (out) | A Tx and Half Duplex Rx |
| 4 | DTR (out) | . |
| 5 | Gnd | Gnd |
| 6 | DSR (in) | B/Z receive for Full Duplex |
| 7 | RTS (out) | A/Y receive for Full Duplex |
| 8 | CTS (in) | . |
| 9 | RI (in) | . |
| Pin | RS-232 |
|---|---|
| 1 | CD (in) |
| 2 | RX (in) |
| 3 | TX (out) |
| 4 | DTR (out) |
| 5 | Gnd |
| 6 | DSR (in) |
| 7 | RTS out |
| 8 | CTS (in) |
| 9 | RI (in) |