Firstly, the Simplex 565-905 duct detector PC board functions for a few models of duct detectors. Also, the Simplex 4098-9686 True Alarm Duct Smoke Detector features an air duct detector housing with a clear cover and factory-installed TrueAlarm photoelectric smoke detector. Besides, comes with a 4098-9601 Photoelectric Smoke Detector. Compatible for use with Simplex Fire Alarm Control Panels that provide conventional 4-wire IDCs (initiating device circuits).
In general, the Simplex 565-905 4-wire operation provides a supervised relay control output that can control up to 15, 4098-9843 control relays. Furthermore, relay supervision troubles are indicate by a yellow LED on the interface board. Optional Remote test station 4098-9835 provides a test key switch, a red LED alarm indicator, and a green power-on LED.