The data busses in aircraft and spacecraft require very high quality in transmission and reception since proper communication of commands and data are crucial to operation. The ARINC 429 standard used predominately in commercial aircraft and the MIL-STD-1553 bus used in military avionics and space vehicles (military and commercial) have some common characteristics as well as important differences. This paper will give useful examples of how to view, test and troubleshoot these busses using digital oscilloscopes. Testing & Debugging Avionics Systems that TECHNICAL BRIEF Use ARINC 429 or MIL-STD-1553 Data Busses Dr. Michael Lauterbach Physical Characteristics January 11, 2012 As with many serial data systems, both ARINC 429 and MIL-STD-1553 are differential busses. ARINC 429 is the simpler and less costly of the Summary two. The physical connection is via twisted pair wires with balanced differential signals. It uses a self clocking, self synchronizing data bus. The data busses in aircraft MIL-STD-1553 uses dual redundant balanced differential pairs. The peak and space……