FOR MORE THAN A HALF CENTURY, fire alarm control panels (FACPs) have used indicating device circuits (IDCs) to channel alarm and supervisory signals from traditional heat/smoke detectors, carbon monoxide (CO) sensors, water level indicators, temperature sensors and other devices.
To do this, supervised normally open contacts within these panels monitor all aspects of the environment through attached devices. Called a conventional FACP, this type of fire panel is still in use today, but is quickly giving way to two additional types of FACPs that are designed to assign a unique identifier to each and every device monitored. One of them uses wireless radio technology and the other a data-oriented, cabled technology.