The RZ100 smoke control panel controls the ASSA ABLOY hold-open devices, holding magnets and door closers/sliding rails with 24V direct current and switches them off in the early stages of a fire or in the event of a power failure, thus ensuring that doors are closed safely.|The RZ100 smoke control panel controls the ASSA ABLOY hold-open devices, holding magnets and door closers/sliding rails with 24V direct current and switches them off in the early stages of a fire or in the event of a power failure, thus ensuring that doors are closed safely.