Vehicle-Mounted lan system, electronic control unit, relay connection unit, and vehicle-mounted lan communication means

摘要

A vehicle-mounted LAN system comprises a plurality of vehicle-mounted LANs in each of which an electronic control unit is connected to a communication line to perform the transmission/reception of messages; and a relay connection unit that relays the messages between the vehicle-mounted LANs. Each electronic control unit has a reception port having a function of transmitting a reception confirmation signal to the relay connection unit in response to a received message. The relay connection unit has a relay management means that determines, based on the presence or absence of the reception confirmation signal responsive to the message relayed to each of the vehicle-mounted LANs, whether a relay is required or not and that then updates relay processing information stored in a storing means.