What is a conventional system and what is an intelligent system?

In conventional systems, detectors are hard wired into a circuit or zone. They signal fire or fault conditions to a control panel by changing from a high to low impedence. The panel detects this impedence change by current monitoring and identifies the zone. Individual detectors cannot be identified.

Intelligent systems incorporate hard wired loops and each device has a unique address code. The control panel carries out a polling routine in which each device is interrogated in a programmed sequence. Devices respond with a status report which, as confirmation that the correct device is responding, includes its own address code. Intelligent systems give advance warning of a developing hazard and pinpoint the individual device raising the alarm. It is possible to follow the spread or progress of a fire as individual detectors report conditions in their area and this could allow a phased evacuation and precise direction of fire-fighting teams.