Integration of the emitting and receiving part makes for easy installation and accurate optical pathway. Built-in microprocessor enables intelligent judgment of fire alarm and fault. Easy alignment ensures a single person installation. Self-diagnostic. Drift-compensation for factors weakness, such as dust contamination, positional excursion and component ageing. Integrated functions for both addressable and conventional use. Electrically address by handheld programmer. Fire and fault volt-free contact output for Integration of the system. 2 sensitivity levels can be set by programmer. SMT processing technology.