Haas Alarm: 957 (M) APC-SWITCH FAULT – Illegal switch condition detected. The pallet clamp switch did not function correctly. Use M17 and M18 commands to verify the input switch (input relay 26) changes state when the pallet clamps and unclamps. Check switch adjustment and check wiring for damage or unplugged connectors. The polarity of the clamp switch may be wrong. Parameter 734 is used to invert input switch polarity.