ELECTRONIC WATCHDOGS.

Supervised home security control systems are considered that use microprocessors and digital communication to shut off different parts of the system if they are not needed or have malfunctioned. The use of microprocessors, both in sensors and in the devices that process sensor signals, is reducing false alarms. Systems can be programmed, for example, to trip the alarm only after two sensors have been activated. Furthermore they can send multiple messages to the monitoring station, requesting either police, firefighters, or an ambulance, depending on the type of sensor signal that has been received. Supervised wireless sytems - in which sensors communicate with controllers via radio - offer still more convenience, since they can be installed without expensive wiring. The use of closed circuit TV (CCTV) is also considered for monitoring and security.