Autronica door monitoring and control unit for interfacing external units onto the AutroSafe system. The BN-320/D-L is designed to be used for maritime installations. The unit is connected to the detector loop to control and monitor different types of doors. Typical applications are interface for fire doors, interface for waterproof doors and interface for lift doors. External units require 24V-working voltage (cannot be powered by the AutroSafe detector loop). The unit has been designed for use with the AutroSafe fire alarm system and comprises the SelfVerify function. This function ensures the highest grade of reliability and reduces the need for manual testing, because all units comprising this function are automatically checked once every 24 hours.