The beam operates totally on the theory of sunshine obscuration employing infrared. The OSI-RI detector is usually a combined transmitter/receiver that can be straight connected to an intelligent detector circuit in LiteSpeed® or CLIP mode. Power and connectivity occur during the imager only plus the OSID-R only needs a single https://www.firesense.co.uk/type/addressable-fire-system/addressable-beam-detectors/