The System Sensor Loop Driver is a plug-in card for use in the ZXa and ZXe intelligent multi protocol fire alarm control panels. This module allows ZXa and ZXe control panels to support input/output points from System Sensor 200 and 500 Series Analogue Addressable devices:

- Smoke Sensors (Ionisation and Optical)
- Heat Sensors
- Omni Sensor
- Filtrex Sensor
- Monitor Modules
- Control Modules
- Isolator Modules
- Conventional Zone
- Addressable Manual Call Points & Pull Stations
- Addressable Sounders
 
The plug-in card provides power for and handles communications to the analog addressable devices. The loop driver continuously monitors the analog values of all sensors and displays this value on the panel as a percentage of the alarm threshold value. Both the alarm and pre-alarm threshold levels can be adjusted from the panel if required. Up to 198 devices (99 sensors and 99 modules) can be connected to a single loop driver. Each device has two rotary decade switches to allow a unique address to be selected. The loop driver can support Class-A and Class-B wiring configurations. Short-circuit isolation and double address detection are built into the plug in card. The AUTO-LEARN facility provided in the ZXa and ZXe control panels saves considerable time and effort when installing a new loop or when changing sensor configuration. It allows the system to learn for itself what devices have been installed on the loop.