The document describes two individual addressable modules (IAMs) that receive power and communications over a single wire pair to provide supervised monitoring of normally open contacts at a location. Model 4090-9001 has a housing and visible LED, while model 4090-9051 is encapsulated without an LED. Both provide up to 500 feet of wiring distance and compatibility with Simplex fire alarm panels for use with IDNet or MAPNET II communications protocols.