Addressable panels are usually more advanced than their conventional counterparts, with much greater information capacity and control flexibility.
Addressable fire alarm panels were introduced by many manufacturers during the microcontroller boom in the mid 1980s.
Addressable Fire Alarm Control Panel employ one or more Signalling Line Circuits - usually referred to as
loops or
SLC loops - ranging between one and thirty. Depending on the protocol used, a Signaling Line Circuit can monitor and control up to several hundred devices. Some protocols permit any mix of detectors and input/output modules, while other protocols have 50% of channel capacity restricted to detectors/sensors and 50% restricted to input/output modules. Each SLC polls the devices connected, which can number from a few devices to several hundred, depending on the manufacturer. Large systems may have multiple Signalling Line Circuits.
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Each device on an SLC has its own unique address, and thus the panel knows the state of each individual device connected to it. Common addressable input (initiating) devices include
Addressable output devices include
- (Warning System/Bell) relays
- Door holder relays
- Auxiliary (control function) relays
- Control modules
- Relay modules
Output devices are used to control a variety of functions such as
- Switching fans on or off
- Closing/opening doors
- Activating fire suppression systems
- Activating notification appliances
- Shutting down industrial equipment
- Recalling elevators to a safe exit floor
- Activating another fire alarm panel or communicator
- Causing emergency exit signs to flash (primarily US, uncommon)