Haas Alarm: 172 (M) APC-PALLET UNCLAMP TIMEOUT – The pallet in the mill did not unclamp in the time allowed. Check for foreign objects between the pallet and the clamp plate. Verify there is an adequate supply of air pressure and air volume. Check air solenoids for sticking and air release ports for clogging. Check the pallet position switch for correct operation, the switch and wiring for damage and pallet alignment. Check the pallet clamp plate for damage. After determining the cause and correcting the problem, run M50 P1 in MDI to recover the pallet changer and then continue operation. Parameter 321 specifies the unclamp timeout period.