Fire Alarm Control Unit Internal Block Diagram

An open fire alarm control unit showing the door display, LEDs and zone map, the CPU and logic board, network interface card, power supply, battery charger, two 12 V 7 Ah batteries, earth ground and plug-in modules for the signaling line circuit, two initiating device circuits, two notification appliance circuits, relays and auxiliary monitoring, with the field wiring for each circuit type and a legend.