Security Monitor IAM model 4090-9121 has both power and communications supplied by a two-wire 4100ES, 4100U or 4010ES IDNet circuit. It provides location specific addressability for up to five initiating devices (such as window or door magnet switch contacts or other similar security devices) by monitoring the circuit wiring connections to either normally closed or normally open dry contacts (one type per IAM). Operation. When the circuit is “armed” by selection from the fire alarm control panel, such as during nonworking hours, monitor loop activity (short, open, or abnormal) causes a priority 2 alarm at the panel. When the circuit is “disarmed”, such as during normal working hours, normal and abnormal conditions would be tracked as events. Depending on the point type selected, an open or short in the monitored circuit wiring will cause a trouble to be reported or a short can be tracked as an event.