An electronic network of communication and processing nodes particularly suitable for control of environmental systems has pluralities of the nodes which are sources for certain types of status messages each of which comprise communication of a particular kind of information on the network. To resolve the question of which of the nodes shall furnish each type of status message, one node is designated the coordinator node, and it stores a status message source list which associates the node assigned for each type of status message with the status message type itself and transmits all or a part of the list on the network to allow each of the status message source nodes to determine therefrom their responsibility with respect to each status message type. These status message source nodes can also transmit request messages on the network by which they request responsibility for furnishing a particular type of status message. Upon acceptance of the request in a request message, the coordinator node enters the node transmitting the request message into the status message source list in asociation with the status message type. In one embodiment, the coordinator node monitors the transmission of status messages on the network and if an instance arises where a status message is supplied by other than the one specified in the status message source list, takes remedial action. In another embodiment each node is given a priority for a particular type of status message, allowing the coordinator node to replace a node assigned to a particular type of status message with another node.