The BR-520 is a component of Furuno's Bridge Navigational Watch Alarm System (BNWAS), specifically the BNWAS Processor. Furuno is a Japanese company that specializes in marine electronics, including radars, fish finders, navigational instruments, and communication devices. The BNWAS is designed to monitor bridge activity and detect any anomalies that may indicate the incapacity of the officer on watch. If the system does not detect any required input from the officer within pre-set intervals, it will initiate alarms to alert the backup officer or crew to take action, ensuring continuous vigilance on the bridge. The BR-520 as a processor unit would typically be central to the BNWAS, managing inputs from various sensors and controls, and coordinating the alarm sequences according to the system's settings and requirements. This includes the initial visual and audible alarms on the bridge, followed by additional alarms in other areas of the vessel if the initial warnings are not acknowledged. Such systems are mandatory on certain types of vessels to enhance maritime safety, as per the regulations set by the International Maritime Organization (IMO).