ARINC 429

ARINC 429 implements a single-source, multi-drop bus with up to 20 receivers .

Messages consist of 32-bit words with a format that includes five primary fields. The Label field determines the interpretation of the fields in the remainder of the word, including the method of translation. The point to multi-point property of ARINC 429 requires the Avionics system to include an ARINC 429 bus for each pair-wise communication.


 MIL-STD-1553

 implements a bus architecture in which all the devices attached to the bus are capable of receiving and transmitting data. The Avionics subsystems attach to the bus through an interface called a remote terminal RT.
The Tx and Rx activity of the bus is managed by a bus controller, that acts to ensure that no two devices ever transmit simultaneously on the bus. The communication is half duplex and asynchronous.