Patent ID: 7358626

Claim:
A method of providing power and communications to a plurality of remotely controllable devices over a single pair of wires in a control system, comprising the steps of: a) connecting to said pair of wires a plurality of devices selectably actuatable to perform a predetermined function in response to an identification and action code; b) transmitting over said pair of wires a single set of direct current power pulses of alternating polarity for powering said devices; each of said power pulses having a first width; c) transmitting said identification and action code over said pair of wires in the form of a train of communication pulses that have a first polarity, and a second polarity; d) measuring said pulses with said selected device; e) determining a polarity of each of said pulses sensed at said selected device and decoding a 1 logic based solely on a first polarity of said pulses and decoding a 0 logic based solely on a second polarity of said pulses; f) causing said selected device to acknowledge receipt of said code or transmit data in response thereto by selectively drawing current in the presence of a transmitted pulse of predetermined polarity.