Addressable panels are usually much more advanced than their conventional counterparts, with a higher degree of programming flexibility and single point detection.

TSIGNALING LINE CIRCUIT LOOPS

Panels usually have a number of signaling line circuit loops – usually referred to as loops or SLC loops – ranging between one and thirty. Depending on the protocol used, a loop can monitor and control several hundred devices. Some protocols permit any mix of detectors and input/output modules, while other protocols have 50% of channel capacity restricted to detectors/sensors and 1/2 restricted to input/output modules. Each SLC polls the devices connected, which can number from a few devices to several hundred, depending on the manufacturer. Large systems may have multiple SLCs, and SLCs are further divided into sub-groups through the use of fault-isolation modules.

Each device on a 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: