A modern, addressable fire alarm is a specialized computer designed to monitor signals from any number of devices and ultimately make decisions about the severity of the situation from the information received. Devices communicate digitally with information including their position and status, and the system is connected to modules used to alert other residents and also local authorities.
A Fire Alarm Control Panel is the central part of any fire alarm system, it's responsible for connections between devices that initiate alarms (detectors, pull stations) on the initiating circuit, and devices that indicate problems (fire bells, strobes, and other communications) on the indicating circuit, as well as all of the logic that goes into where and when to use the information.
FACPs need to be checked with regularity to ensure they are working correctly to manufacturer specifications, including testing of all circuits and devices, as well as batteries and external connections in the event of a real emergency or power failure.
Non-addressable or conventional FACPs work exactly the same as addressable panels, but lack the digital communication between devices. Instead, devices are arranged on loops (called zones) which are used to distinguish between different floors, buildings, or areas of a building depending on the configuration.
Problems are detected digitally in the case of addressable panels and are detected by changes to the state of the circuit in the case of conventional panels. Electronic switches inside each device correlate to alarms or troubles in the system, this information is interpreted and organized for display and reporting by the FACP.
Manual pull stations are required to be placed beside exits, and are a simple switch that tells the FACP a fire has occurred. Some other components sense problems automatically: