The M501MEA provides a two-wire initiating circuit for normally open contact fire alarm and security devices. In addition to transmitting the supervised state of the monitored device (normal, open, or short), the full analogue supervision measurement is sent back to the panel. The compact size allows it to fit inside devices or junction boxes behind devices. Its size and light weight allows it to be installed without the need to be rigidly mounted. Enabling the Advanced Protocol, alarms or troubles are determined in a reduced time.