"Each computer in a redundant set operates in synchronized steps and cross-checks results of processing about 440 times per
second. Synchronization refers to the software scheme used to ensure simultaneous intercomputer communications of necessary
GPC status information among the primary avionics computers. If a GPC operating in a redundant set fails to meet two redundant
synchronization codes in a row, the remaining computers will vote it out of the redundant set. Or if a GPC has a problem with its
multiplexer interface adapter receiver during two successive reads of response data and does not receive any data while the other
members of the redundant set do not receive the data, they in turn will vote the GPC out of the set. A failed GPC is halted as
soon as possible."
Acknowledgement: NASA Shuttle Reference Pages
