The AlarmLine II Analogue EN Linear Heat Detection (LHD) system comprises of AlarmLine II Analogue EN Linear Heat Detection (LHD) sensor cable (AAE-xxxx), a AlarmLine II Analogue EN Controller (AAECU) and a AlarmLine II Analogue EN end of line unit (AAECUEOL). The controller provides monitoring of the AlarmLine II Analogue EN 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.