Patent ID: 7616090

Claim:
An electronic security system comprising: a power line having exactly two wires; a power supply electrically connected to the power line and including a power supply module, the power supply module configured to receive electrical power, to selectively receive operational instructions, to modulate the electrical power with the operational instructions, and to supply the modulated electrical power through the power line; a plurality of electronic security devices electrically connected to the power line, and configured to be powered with the modulated electrical power from the power line, each including an input/output module configured to receive the modulated electrical power, to decode the modulated electrical power to retrieve the operational instructions, to program the electronic security device based on the retrieved operational instructions, and to operate the electrical security device with the modulate electrical power and the programmed operational instructions; wherein the power supply module also includes a multiple power supply module interface configured to couple the power supply module to and to transmit programming signals to another power supply module of another electronic security system via a line.