The Furukawa Electric Co., Ltd.

Mazda Motor Corporation

Teruhisa Inoue

Osamu Michihira

Yutaka Matsuda

Yusaku Himono

Kiyoshi Inoue

Yuichi Ito

Seiji Hirano

Kyosuke Hashimoto

Atsuhiko Suzuki

Kyousuke Hashimoto

Kyosuke Hasimoto

Makoto Muto

A device for controlling the current consumption of a power supply which applies a voltage to a transmission control circuit for transmitting a transmission signal with respect to a transmission line is provided. A power supply stabilizing circuit for stabilizing a voltage applied from the power supply; an amplitude detection circuit for detecting a transmission signal input from the transmission line; a switching circuit for interrupting application of a voltage from the power supply stabilizing circuit to the transmission control circuit; and a control circuit for controlling the open/closed state of the switching circuit according to the presence or absence of a transmission signal detected by the amplitude detection circuit are provided, and only when the amplitude detection circuit has detected the transmission signal, the control circuit sets the switching circuit into the closed state so as to permit a voltage to be applied to the transmission control circuit. When no transmission signal is transmitted, application of an unnecessary voltage to the transmission control circuit is interrupted, thereby reducing the current consumption.

Current consumption control device

A multiplex transmission system, in which a node as a transmission node transmits data frame by frame to a transmission path, and a plurality of other nodes, as reception nodes, returns a reception acknowledgment signal to the transmission path upon proper reception of the frame of data. Each of the reception nodes which properly received the frame returns the reception acknowledgment signal specific thereto to that division of a reception acknowledgment signal area in the frame which corresponds to this node. Each node discriminates the success/failure of signal transmission, by comparing the information registered beforehand in its reception acknowledgment signal table with the information in the reception acknowledgment signal area. When the information of the reception acknowledgment signal table does not coincide with that of the reception acknowledgment signal area, the transmission node re-transmits the frame and the reception acknowledgment signal tables of all the nodes are updated. The system can not only effect the addition and deletion of multiplex nodes easily without requiring the change of scale of the circuit of the system, but also discriminate trouble for each of the multiplex nodes.

Multiplex transmission system

A multiplex transmission system, in which a plurality of nodes are coupled together through a transmission path, and a node as a transmission node transmits a frame of data including a data area containing transmission data, to other nodes as reception nodes through the transmission path. The frame of data includes a data valid/invalid area having the same bit length as the data area and indicating, bit by bit, the validness/invalidness of the data carried by the corresponding bits in the data area. The system need not be modified depending on the model and grade of vehicles, and can be used widely and applied to various options by the use of a signal allocation system common to different models and grades of vehicles. Those bits in the data area which correspond to the bits in the data valid/invalid area indicative of data invalidness may have values thereof set to a fixed value, so that the reception node judges the transmission node to be defective when a bit of the data valid/invalid area of the received frame and the corresponding bit of the data area of the received frame make a combination of specific values.

A multiplex transmission system, in which one of a plurality of nodes, as a transmission node, mutually coupled together through a transmission path transmits data frame by frame to at least one of other nodes as at least one of reception node, and the reception node returns a reception acknowledge signal to the transmitting node upon proper reception of the frame of data. A reception acknowledge signal area comprising a plurality of bits is provided following the frame transmitted from the transmitting node. The reception acknowledge signal area is divided into a plurality of bit areas which are respectively assigned to the plurality of nodes. The reception node returns the reception acknowlege signal to the transmitting node from the respectively-assigned bit areas of the reception acknowledge signal area. As desired, a destination designation area having the same length as the reception acknowledge signal area is provided in a frame and is divided into a plurality of bit areas which are respectively assigned with the plurality of nodes. The individual destination nodes are specified by the respective bit areas of the destination designation area of the frame. Preferably, a pulse width modulation code for discriminating the binary logic based on the size of the pulse width is used as a transmission code at least in the reception acknowledge signal area.

Growing community of inventors

Ichikawa, Japan

Teruhisa Inoue