Dmc 4 stop duplex
One car lost parameters said cood start
The other car would bot respond to hall calls only
Resetup everything both cars are back but no hall calls at all

Check to see if both cars are master. One has to be slave car.

It was dead battery on clc maint. Man cycled power for unknown fault lost everything on one elevator. Still dont know why it took out hall calls to other car but after doing all adjustments and reloading the saved parameters everything came back good