Originally Posted by
TTex600
Continuous trim motion is not a design given. Being continuously in trim is.
I just want to make sure we're not misunderstanding each other here. By "continuous", I don't mean continually moving in one direction, I mean "changing regularly". The way the system works in pitch (as I'm sure you know) in Normal and Alternate is that the pilot (human or auto) commands a flightpath, the elevators move to the required setting to achieve that flightpath, and the autotrim then relieves the elevators. This kind of banal repetitive action is what computers are naturally good at, and because of this the system is constantly correcting itself. Somewhat different from traditional use of trim, but certainly effective.
A warning noise that sounds during "trim in motion" is therefore a bad fit for this design.
A warning that trim has exceeded a certain value could be of some value, but an indication of continuous (run away, even if by incorrect stick inputs) would be worth more.
A warning predicated on limits would be simpler (less complexity = less chance of error) to implement.