The beam operates primarily on the basic principle of light obscuration utilizing infrared. The OSI-RI detector is a merged transmitter/receiver which can be straight linked to an smart detector circuit in LiteSpeed® or CLIP mode. I agree to Ampac delivering software updates, solution updates, presents and promotions by using email https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/