Mazda Motor Corporation

Naldec Corporation

Mazda Motor Corporation and Naldec Corporation

Yasuhiko Kurata

Yuichi Akiyama

Osamu Michihira

When it is detected that the state of an electrical component connected to a communication node has not changed in the OFF state of an ignition key switch, it is determined that a vehicle equipped with the multiplex transmission apparatus is in a parking state, and the communication node is forcibly shifted to a sleep state, thereby preventing consumption of battery power due to a dark current supplied to the communication node in the sleep state.

Multiplex transmission apparatus

The number of control nodes, of a plurality of control nodes distributed/connected to a common multiplex transmission path, which can exchange data with each other, is counted and data communication between the plurality of control nodes is performed while each control node prolongs the data transmission period as the number of control nodes, i.e., the number of control nodes which can exchange data with each other, increases.

Multiplex transmission apparatus and method

The output interval between a signal for shifting a communication node from a sleep state to a wake-up state and a signal for operating an electrical component is set to be longer than the wake-up rise time of the communication node. After the communication node is reliably shifted to the wake-up state, an operation signal can be transmitted to the electrical component, and an unnecessary dark current can be prevented from being supplied to the communication node in the wake-up state.

In a multiplex transmission apparatus, multiplex transmission paths to each of which a plurality of communication nodes are connected through a gateway node. When data transfer between the multiplex transmission paths is disabled, data are temporarily saved in a stack according to priority order of data, and when the saved data are transmitted, the data are transmitted on the basis of the priority order and the storage order of the data, thereby preventing omission of transfer data.

Growing community of inventors

Higashihiroshima, Japan

Yasuhiko Kurata