These range from outdoor lighting to security sensors. The VCR when programmed is also considered an individual control device. A distributed-control system uses standard electrical wiring, telephone wire, video wire, radio frequency signals, and infrared signals. Microchips must be installed in appliances or outlets to allow communication over regular home electrical wiring. A central controller is not required although keyboard entry is possible using telephones or personal computers.
Homeowners can use a television set to monitor the system's status.
Centrally controlled systems route signals between a central computer and appliance controllers or sensors. This system can control all appliances whether microchips are present or not. If the controller fails, however, the whole system fails. If the system determines that all is well, the network box sends power to that outlet. If the network senses potential danger, such as a frayed cord, or appliance incompatibility, power is denied to the outlet.