Cause : VPL/MC Comm Fail comes when a communication failure has occurred between the Velocity Position Loop (VLP processor and the Motor Control (MC) processor on the main control board. Possible causes are:

• MC has failed to complete or pass diagnostic tests This is Indicated when Fault Test Point 16 equals 1. This test point is viewed in parameter 330 [Fault TP Data] when parameter 329 [Fault TP Sel] equals 16 “VPL Handshak”.

• VPL has not detected MC handshake activity for over 32 ms. This is Indicated when Fault Test Point 16 equals 1. This test point is viewed in parameter 330 [Fault TP Data] when parameter 329 [Fault TP Sel] equals 15 “MC Handshake”.

• MC has not detected VPL handshake activity for over 32 ms.