ARINC 429 is the standard avionics data bus for commercial aircraft using a balanced differential pair at 12.5 or 100 kbps. DB25 connectors aggregate multiple ARINC 429 bus pairs on avionics equipment front panels.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | TX1_A | Bus 1 transmit positive | BUS |
| 2 | TX1_B | Bus 1 transmit negative | BUS |
| 3 | RX1_A | Bus 1 receive positive | BUS |
| 4 | RX1_B | Bus 1 receive negative | BUS |
| 5 | TX2_A | Bus 2 transmit positive | BUS |
| 6 | TX2_B | Bus 2 transmit negative | BUS |
| 13 | SHIELD | Cable shield | GND |
| 14 | GND | Ground | GND |