ARINC 404 defines the physical interface for avionic equipment trays and connectors in aircraft equipment racks, specifying the mechanical and electrical interface between LRUs and the aircraft wiring harness.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | Power | Aircraft 28V DC or 115V AC power | PWR |
| 2 | Discrete | Discrete signal contacts | I/O |
| 3 | Data | ARINC 429 or RS-232 data | BUS |
| 4 | GND | Ground | GND |
ARINC 404 defines the physical interface for avionic equipment trays and connectors in aircraft equipment racks, specifying the mechanical and electrical interface between LRUs and the aircraft wiring harness.