ARINC 429 is the most widely used data bus standard for commercial and transport aircraft. Formally known as the Mark 33 Digital Information Transfer System (DITS), it defines how avionics components—such as flight management computers, radios, and GPS sensors—communicate with each other using a standardized digital format. Avionics systems are interconnected by wires in twisted pairs. The specification defines the data protocol and electrical charanteristics. 

Messages are transmitted at a bit rate of either 12.5 or 100 kbits per second.