Hey there, we are having a very similar issue with one of our elevators.
Getting faults:
1695: No UCA board communication
1732: Controller lost Comm with UCA
1673: UPS problem caused non emergen stop.
Can not find any information regarding these faults in the Endura MRL Product manual. Just skips right over them! We can reset this unit and the car will run for about a month and then this happens again. We are going to change the UPS today and possibly the UCA board if the problem persists but would love some extra help regarding the fix for this issue.
Thanks!