VEHICLE MULTIPLEX COMMUNICATION SYSTEM

A vehicle communication multiplex system comprises: a bus; and a plurality of nodes connected to the bus, wherein transmission right circulates to the nodes in a predetermined order and send a predetermined number of data to the bus from the node which gets the transmission right. Each of the nodes includes, a block division section for dividing the data into blocks to prepare data blocks, a change-block-determination section for determining whether or not each of the data blocks prepared by the block division section changes as an event occurs, and a data transmission section, if the change-block-determination section determines that a data block changes, for extracting the data block from the block division section and sending the extracted data block to the bus.