Patent ID: 8121132

Claim:
A control network in a building for wired coupling of at least one analog device to a data unit, the network comprising: a plurality of nodes including first, second and third nodes; and a plurality of wiring segments including first and second wiring segments, each wiring segment comprising at least two conductors, wherein said first wiring segment connects said first and second nodes together in a point-to-point connection, and said second wiring segment connects said second and third nodes together in a point-to-point connection, wherein: said first and second nodes effect bi-directional communication of serial digital data over said first wiring segment and said second and third nodes effect bi-directional communication of serial digital data over said second wiring segment, at least one of said nodes is connectable to a data unit for coupling the serial digital data carried over at least one of said wiring segments to the data unit, at least one of said nodes comprises an analog/digital or digital/analog converter connectable to the analog device for coupling the serial digital data carried over said at least one of said wiring segments to the analog device, the analog device is a sensor or an actuator, each of said nodes is addressable in said network, and each of said nodes is connected by a respective pair of said wiring segments to only two other nodes, said nodes are connected by the wiring segments in a ring configuration, each of said nodes is in direct signal conducting communication only with a unique pair of other nodes and one of the data unit and the analog device, and each of said nodes is operative to be in a selected state to conduct data in both directions around the ring.