What is ARINC 429 and how is it used in avionics?

ARINC 429 is the predominant data bus standard in commercial aviation for communication between avionics equipment. Characteristics include: Unidirectional transmission (one transmitter, multiple receivers), Twisted pair wiring (simple, reliable), Data rates of 12.5 or 100 kbit/s, 32-bit word format (8-bit label, 2-bit source ID, 19-bit data, 1 parity bit), and Point-to-point or broadcast architecture. Each data type has a defined label (e.g., airspeed, altitude). ARINC 429's simplicity and reliability make it widespread, though ARINC 664 (AFDX) provides higher bandwidth for modern integrated avionics. ARINC 429 remains in use for many legacy and new systems due to proven reliability.