Analogue addressable devices are individually identified with an address (number) on a loop of wiring. The control panel communicates with each device in turn and each device reports back an analogue value based upon how much smoke or heat is present. The control panel, not the detectors, then makes all the decisions with regard to sounding the alarms.
With an intelligent system, if a fire is detected, its position can be pin-pointed because each device has its own unique address which means its location can be found precisely.
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