RS-422 uses balanced differential signals on a 9-pin D-sub for longer distance serial communication than RS-232, supporting up to 10 Mbps over 1200m with noise immunity for industrial equipment.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | TX- | Transmit data negative | BUS |
| 2 | TX+ | Transmit data positive | BUS |
| 3 | RX+ | Receive data positive | BUS |
| 4 | RX- | Receive data negative | BUS |
| 5 | GND | Signal ground | GND |
| 6 | TX- | Transmit negative alt pin | BUS |
| 7 | TX+ | Transmit positive alt pin | BUS |
| 8 | RX+ | Receive positive alt pin | BUS |
| 9 | RX- | Receive negative alt pin | BUS |
RS-422 uses balanced differential signals on a 9-pin D-sub for longer distance serial communication than RS-232, supporting up to 10 Mbps over 1200m with noise immunity for industrial equipment.