The beam operates primarily on the basic principle of light obscuration using infrared. The OSI-RI detector is often a mixed transmitter/receiver which might be right connected to an smart detector circuit in LiteSpeed® or CLIP mode. The 302-ET-194 Thermotech charge-anticipation heat detector from Honeywell NOTIFIER operates within a managed array https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/