Digital data transmission system using AC mains network - uses signals from central station superimposed on AC voltage for communication between units in network

摘要

The mains power supply is used as a transmission medium for information. A central control and terminals are connected to the same mains network to enable digital information to be transmitted along the network between the units by superimposition of the information on the mains voltage. The system makes use of a ready made and installed network and avoids the need for purpose built links between units.