Message or Data
the information sent by a communications system.

Module
in home automation, a device for interfacing controllers with security devices, lamps, appliances, and other devices. Each module has an address which may be unique or may be the same as other modules.

Monitoring Service
see Central Monitoring Station

Motion Detector
Passive InfraRed: PIR: An intrusion detector designed to register changes of temperature, which occur when an intruder enters a protected space.