The AACUSP is a self programmable, Analogue Linear Heat Detection (LHD) cable control unit. It provides monitoring for any of the Alarmline II range of LHD sensor cable, configuration of alarm and pre-alarm temperatures as well as enabling simple interface to a main fire alarm or BMS system.

As well as monitoring the LHD sensor cable for changes in temperature, the control unit also monitors for open and short circuit faults along the cable ensuring notification if the cable becomes damaged. It is fitted with its own internal temperature monitor and should the temperature within the controller enclosure reach 100°C (212°F) an alarm will be signalled.

Each control unit may have up to 500m (1640ft) of LHD sensor cable connectef to it, acting as a single detection zone. When the LHD sensor cable and the control unit are installed in different areas, a suitable interposing cable can be used to make the electrical connection between them. 

The AACUSP provides LED indications as well as an LCD. Internal pushbuttons allow configuration without the need for a PC. Pre-Alarm and Alarm thresholds can be set trough simple menu options with no need for any graphs or nomograms. Initial set up is done by measuring and entering the calibration resistance of the sensor cable removing the need to know the sensor cable length. 

Volt free changeover contacts are provided inside the control unit for Pre Alarm and Alarm signalling to a main fire alarm control panel or BMS system. A failsafe opto-isolated phototransistor fault output is also provided. 

No user controls are provided on the control unit. An isolated input is provided enabing remote reset functionality.