An issue was observed in which the target hall crane was not functioning: the N-E-S-W and up/down motions did not work, however the rotation motion did work. These symptoms were similar to what was observed in the past under https://elog.triumf.ca/TIS/RH-ISAC/2039 and https://elog.triumf.ca/TIS/RH-ISAC/1845

The crane control console was not powered (i.e. pressing the ON/OFF buttons when the selector switch was set to remote mode, even when safety conditions were met, did not enable/disable remote functionality). The power supplies were checked and everything appeared to be powered as would be expected, except for items which depended on the main contactor (O-K1) being energized. This contactor needs the PLC to be in an operational state, fault-free. The PLC was checked and the red fault light was flashing. The battery light was not on (i.e. battery was OK).

The program was re-downloaded to the PLC. During an attempt to go online with the PLC, error code 0004h appeared (see attached image for description). This is an unfamiliar error code - typically the aforementioned symptoms arise due to a battery failure and the program being lost. In this case it is uncertain at this time what the cause of this fault is. It will be monitored in the future to determine if it occurs again, and further investigation will be performed.

After re-downloading the program and placing the PLC in RUN mode, the crane was fully restored to its operating state - the main contactor was able to be energized once again. The crane was put into remote mode and a brief functionality test on the motion axes was performed: OK.