What buss format is used for the electronic interface on the Boeing 777 ie. 1553, USB, Custom Parallel, etc? Is there a Buss Mgt. controller to link multiple busses together or is there one Master Buss with the Flight controller Computer having assigned registers for each instrument that outputs it's data to? Having integrated many large systems, with lots of equipment outputing data for other computers/instruments to use, I know that there is always a need to make sure that all the instruments are behaving correctly - ie. rise time, pulse widths, signal cross talk, etc. Is there test ports (where test equipment is plugged into the buss)? How many are there and where are they located? Is there a test port located in the front landing gear "wheel well" - that is where fighter planes have a lot of their commonly used test connectors located?
Is there a piece of ground equipment plugged into that port before each flight, so that an equipment BIT is run?