Patent ID: 8719477

Claim:
A communication system comprising: a bus and a plurality of nodes including a master node and a plurality of slave nodes, the plurality of nodes being communicably coupled to each other through the bus; the master node is configured to transmit, in a passive communication mode, at least one of: first identification information and second identification information on the bus, the first identification information representing start timing of the passive communication mode, the second identification information including at least first designation of one of the plurality of nodes allowed to transmit data; the master node is configured to transmit, in an active communication mode, third identification information indicative of start timing of the active communication mode on the bus; when a request of an active communication occurs in at least one of the plurality of nodes, the at least one of the plurality of nodes serves as a request node in the active communication mode to receive, from the bus, the third identification information and successively transmit, on the bus, the third identification information and a second designation of at least one of the plurality of nodes allowed to transmit data; each of the plurality of nodes is configured to, when receiving any one of the first designation and the second designation as designation information that designates the corresponding node, transmit; on the bus, the designation information, and, subsequent to the designation information, data; the first identification information and the third identification information are designed to be identifiable from each other based on a former part of the first identification information and a former part of the third identification information; the request node is configured to, when determining to receive the former part of the first identification information, transmit, on the bus, collision information at a timing that allows the collision information to collide with a latter part of the first identification information, resulting in rewrite of the first identification information based on arbitration on the bus between the collision information and the latter part of the first identification information; and the request node is configured to regard the rewritten first identification information as the third identification information, and to operate in the active communication mode.