Patent ID: 7619322
Filing Date: 2009-11-17
Classification: G05B,H04B,H04L,Y10T

Abstract:
1. 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: 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; transmitting over said pair of wires direct current power pulses of alternating polarity for powering said devices; each of said power pulses having a first width and either a first polarity or a second polarity; each of said power pulses delimited from each other by a no-power segment; actuating a selected one of said devices by transmitting said identification and action code over said pair of wires in the form of a train of communication pulses that have said first polarity for logic 1, and said second polarity for logic 0; and 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.