In a conventional panel, fire detection devices including, but not limited to smoke detectors, flame detectors, heat detectors and manual call points or manual pull stations joined up with a number connected to each circuit. When a device on the circuit is activated, the panel recognizes an alarm on that circuit and could be set up to take a number of actions including directly calling the fire department via an alarm transportation system (ATS).
Conventional Panel
Conventional panels have been around ever since electronics became small enough to make them viable. They are no longer used frequently in large buildings, but are still used on smaller sites such as small schools or apartments. Conventional panels usually have a small number of circuits, each circuit covering a zone within the building. A small map of the building is often placed near the main entrance with the defined zones drawn up, and LEDs indicating whether a particular circuit/zone has been activated. Another common method is to have the different zones listed in a column, with an LED to the left of each zone name.
The main drawback with conventional panels is that one cannot tell which device has been activated within a circuit. The fire may be in one small room, but as far as emergency responders can tell, a fire could exist anywhere within a zone.
Loops
Panels usually have a number of loops within the range of two to 20 loops. At the present time, four or six loop panels are the most common.
Each loop can have a number of devices connected to it. Each device 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
- Manual Call Points or Manual pull Stations
- Responders
- Fire Sprinkler inputs
- Switches
- Flow control
- Pressure
- Isolate
- Standard switches
Addressable output devices are known as relays and include
- (Warning System/Bell) Relays
- Door Holder Relays
- Auxiliary (Control Function) Relays
Relays 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
Since their inception, loops have generally been able to handle 99 devices. More recently however, new protocols have been designed that allow 256 devices on each loop.
Mapping
Also known as "Cause and Effect" or "Programming", 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.
