A control network comprises a plurality of network nodes arranged in a plurality of tiers, with first-tier nodes and lower tier nodes. A master control bus interconnects the first-tier nodes, which are also connected to a power source. Lower-tier buses interconnect groups of the lower tier nodes. The...http://www.google.fr/patents/US7724778?utm_source=gb-gplus-shareBrevet US7724778 - Control network with data and power distribution
