Fire Alarm Systems can be divided into two main categories: addressable and conventional systems. Though both of them achieve the same goal of detecting fire, many differences exist between the two systems in terms of functionality, reliability, complexity, application, and cost.
An addressable fire alarm system includes addressable devices that permit the end user to determine the exact location of the fire. In contrast, the conventional system divides the protected area into zones comprising one or more fire detection devices. Hence, if a fire occurs, the conventional system indicates the zone where the fire happened not the exact device like in an addressable system.
In conventional systems, a 2-wire cable runs from the fire panel and connects to the detection devices (detectors and pull stations / call points). In case of a wire breakdown, the detection devices lose their ability to send signals to the panel. In addressable systems, a 4-wire cable runs through the detection devices in a loop form, making each device connect to the panel from both sides of the loop. Hence, in case of a wire breakdown, the detection devices can still communicate with the panel.
Addressable systems are capable of building correlations between the different devices and circuitries present in the loop. The devices are more intelligent and thus permit the engineer to create multiple fire scenarios as required by the application. On the other hand, conventional systems have limited ability to create these correlations.
Addressable systems are usually specified in medium to large applications whereas conventional systems are used in small to medium applications.
Addressable systems are more intelligent than conventional ones; this makes their cost higher.