Today while operating the crane with load, the crane stopped moving. Upon investigating, all safety signals appeared to be OK. Fault messages regarding drive faults for various VFDs were present, which seemed to stem from an ethernet adapter card fault (see attached photo). It is unknown how this occurred, but suspected that it was due to a brief blip in network communications or the external drive power supply control signal. It is worth noting that the diesel generator tests took place today, and there could have been some affect from a power surge because of this.

The crane was power-cycled using the main disconnect, and safety system reset. The faults disappeared. The crane was operational again.

If this issue occurs again, it should be investigated more thoroughly. It would be worth checking if there were any generator tests or other things which could cause some sort of power surge.