Abstract: A data transfer communication system capable of handling both node-to-node data transfer messages originating at any transmitter and transmitted to a specific receiver on the network and functional command messages originating at any transmitter and broadcast transmitted to an unspecified number of receivers on the network. Receivers are programmed to receive and acknowledge receipt of correspondingly addressed node-to-node type messages and certain correspondingly addressed functional command type messages with their unique addresses in a predetermined field location of the transmitted message. By utilizing pulse width modulation techniques, binary logic signals and a unique start signal are defined and have a dominant hierarchy that allows for bit-wise contention of the common data bus. In that manner, when contention of the data bus is resolved a higher priority message continues to be transmitted while losing contender delays its transmission until after the higher priority message is completed.