FCC software design in the 1980s (A320)
Bernd and Dozy,
The flight control computers on the A320 - ELACs (2 off) and SECs (3 off) - each have a control channel and a monitor channel. IIRC, in both cases the software for the control side was written by a different team from the monitor side. (The ELACs come from a different vendor to the SECs.)
There is no voting system. If a monitor channel is in disagreement with its control channel, the relevant computer shuts down.
Bernd, you are of course right (correct!) to say that the design team has to know what it needs, and communicate its requirements to all the software teams without ambiguity. IIRC, they used either Maths or logic diagrams (AND/OR gates, etc.).
Last edited by Chris Scott; 23rd January 2013 at 13:14.
Reason: Title and third para added.