Token passing communication network including a node which maintains and transmits a list specifying the order in which the token is passed

Claim 1

In a communications network comprising a plurality of master nodes all connected to a single data bus comprising a pair of electrical conductors and each node including a node address register whose contents are a node address preassigned to the node, each of the nodes of the type having an active mode during which the node may provide on the data bus a plurality of different messages comprising electrical signals for communicating with the other nodes, and each of said nodes including a successor address register dedicated to storing a network address different from the content of the node address register, said active mode of a node being initiated responsive to receiving on the data bus signals encoding a token message having a preselected unique identifying format and including a successor address equal to the contents of the node address register of the node, and each said node further transmitting a token message including a successor address comprising the address stored in the successor address register of the node and terminating the active mode responsive to the receipt on the data bus of a token acknowledge signal having a preselected unique identifying format, and wherein a first of the master nodes includes an address memory in which may be stored an active master list including the contents of the node address registers of active master nodes in the network and further, specifying a successor address for each of the node addresses included in the active master list, the improvement comprising (a) in the first of the master nodes, an active master list broadcast means for providing signals on the data bus encoding therein an active master list message having a preselected unique identifying format and including at least a part of the active master list stored in the address memory; and (b) in each of the master nodes, means for receiving the active master list message on the data bus from the first of the master nodes, means responsive to the active master list message identifying format for extracting therefrom the successor address specified in the active master list for the network address of the master node involved, and means for storing the network address so extracted in the successor address register of the master node involved.