Addressable Fire Alarm Systems

An addressable fire alarm system is one in which all fire and smoke detection devices in a system are connected together and communicate both with each other and a central control monitoring location. The interconnectivity allows the control personnel to identify the “location” or “address” where the initial detection has occurred. The information directs the emergency response team to channel their efforts immediately to the precise location of the developing problem.

Linking all devices offers several advantages that are not possible with traditional independent fire alarms. Some of the benefits of an addressable system are:

Accurate identification of where the problem started and where it may be spreading
Specific actions can be programmed such as delaying evacuations from areas not immediately threatened, there by reducing bottlenecks of evacuating occupants
Reduces potential for false alarms
Each element of the system can be monitored routinely for operational health
More reliability, less likely to lose connection.
Lower overall cost of wiring.

Addressable panels are usually more advanced than their conventional counter parts, with greater information capacity and control flexibility.

Signalling Line Circuits

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 signalling line circuit can monitor and control several hundred devices.

Each device on an SLC has its own address, and so the panel knows the state of each individual device connected to it. Common addressable input (initiating) devices include

Smoke detectors
Heat detectors (Rate of Rise and Fixed Temperature)
Manual call points or Manual pull stations
Notification appliances
Responders
Fire sprinkler system inputs
Switches

Flow control
Pressure
Isolate
Standard switches
Monitor modules

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

Mapping

Also known as "cause and effect", mapping is the process of activating outputs depending on which inputs have been activated. Traditionally, when an input device is activated, a certain output device (or relay) is activated. As time has progressed, more and more advanced techniques have become available, often with large variations in style between different companies.

Zones

Zones are usually made by dividing a building or area into different sections. Then depending on the specific zone, a certain number and type of device is added to the zone to perform its given job. Zones are a requirement by the National Building Code in Canada and zones must be labelled and include RED LEDs for fire zones, AMBER LEDs for supervisory and trouble. This is in addition to an LCD display although they relax this requirement if the LCD has 8 or more lines of characters. Isolators are also required when wiring departs a zone and enters a new zone such as floor to floor and between firewalls.

Groups

Groups contain multiple output devices such as relays. This allows a single input, such as a smoke detector or MCP, to have only one output programmed to a group, which then maps to multiple outputs or relays. This enables an installer to simplify programming by having many inputs map to the same outputs, and be able to change them all at once, and also allows mapping to more outputs than the programming space for a single detector/input allows.

Boolean Logic

This is the part of a fire panel that has the largest variation between different panels. It allows a panel to be programmed to implement fairly complex inputs. For instance, a panel could be programmed to notify the fire department only if more than one device has activated. It can also be used for staged evacuation procedures in conjunction with timers.