TOKEN PASSING BUS COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To have it so that a node without transmission data need not be transmitted. SOLUTION: A communication node 2 transmits a transmission frame to which transmission stop data is added on a bus 3, when the self node executes transmission, for example. Transmission stop data shows the number of transmission stop times. Two-cycle transmission is not executed from next transmission, and transmission stop data '2' is transmitted at the time of executing transmission in a third cycle, for example. When the other nodes receive the transmission frames, they hold '1' as stop data for the node 2, for example. At the time of the transmission of the next cycle, the respective nodes view transmission stop data, which are kept and transmission is executed by skipping the node of transmission stop. Thus, the node without transmission data does not need to execute transmission every time. Consequently, the specified node can obtain transmission right at a rate larger than the other nodes, and the communication efficiency of an overall communication system improves.