At both intermediate and terminal landings, the controller will log a motion excuse 40. According to the log, this happens with target and position at the same floor (100 * 40 0 0 P:2 T:2 00%LD for example). After experiencing this fault a seemingly random number of times, the controller takes the car out of service and states "Retry Limit Error" on its last instance of the 40 fault.

The literature suggests replacing the vane reader and encoder board on the cartop. Check. It has been replaced.
It suggests replacing the 150fpm speed board attached to the ETS board. I have swapped that board with the other car in the duplex and that has not fix it or moved the problem.
I have checked the wiring of both the car top encoder and the motor encoder. I know my position encoder is tracking with the rail properly and is properly grounded.
When viewing motion averages I have seen it once so far. Indeed RL1 is seen at 3F/M far out of its 150 tolerance.

So, what do y'all think? Could it be the car top encoder? ETS board? MSU? This is unfortunately so intermittent I have only ever seen it happen a couple times. I really appreciate any suggestions. Thanks.