Originally Posted by
Europa01
If I read 27-41 correctly in Smythe's #951 post, the 8 -9 contacts are the FCC (and hence MCAS) route direct to the Eaton stab motor. As has been discussed this item is clearly more than just a motor and very little information about its architecture seems to be available. Terms such as 'processor based' could mean anything but are probably chosen carefully and probably don't mean microprocessor controlled. In my industry (nuclear) there are rigorous technical protocols for assessing and verifying embedded software on safety critical equipment and I'd be astonished if there is not something very similar in aerospace.
what I understand from those drawings is that a black box called controller collects both main trim and AP trim, and that drives the motor, what logic is inside that black box, what type of signals are coming from two other black boxes is not known...yet.
note that such controller does not have any input to any interlock...