Hitachi, Ltd.

Fumio Hamano

Shigeru Oho

Takeshi Hirayama

Akira Hasegawa

Takanori Shibata

Masahiro Matsumoto

In a data transmission system having a data processing unit (MPU) and a communication control unit (CIM) and capable of transmitting a data to a local control unit (LCU) in a half duplex mode, the data processing unit receives the data by an interruption based on an end of data reception signal supplied from the communication control unit.

Data transmission system having a communication control computer for

A collective wiring system for an automobile provides a central control unit which communicates with a plurality of terminal control units each connected to one or more input or output devices, such as switches, sensors, motors and the like. The control over output devices in response to the status of input devices is performed by the central control unit on the basis of tables of data stored in memory. A scan table controls the order in which data communications are made to the terminal control units to obtain their status and provide them with control commands. A monitor table stores the current status of the terminal control units and a control table stores the control data for the terminal control units. A connection table stores the relationship between the terminal control unit for an input device and the terminal control unit for the output device to be controlled thereby. Thus, connection control between input and output devices is effected by software.

Collective wiring system and method of control thereof

Data transmission system

In a data transmission system having a central control unit including a data processing unit (MPU) and a communication control unit (CIM) which is capable of transmitting data to a local control unit (LCU) in a half duplex mode, the data processing unit receives the data in an interruption based on an end of data reception signal supplied from the communication control unit. At the time of initialization of the system, the central control unit responds to the application of power to the system by transmitting predetermined control data to the local control unit to set the state of accessory devices connected thereto, thereby preventing improper operation of the accessory devices during system startup.

Control method for a collective wiring system

A terminal device for a multiplexed data transmission system has a decoder matrix having plural groups of function setting inputs for selecting plural types of functions such as interface, operation modes and other. One group of the function setting inputs are preferably address designating signals which are utilized for determining the interface. The other group of the function setting inputs determines various additional functions such as, for example, enabling/disabling of fail-safe function and automatic transmission function. Selection with the aid of the matrix allows selection of a large number of functions with a small number of input signals. Utilization of the address signals to this end allows the number of terminal pins to be decreased to a minimum.

Terminal for data transmission system

A multiplex communication system comprises a central control unit, a plurality of local control units, an optical loop transmission path interconnecting the central control unit and the plurality of local control units by optical fibers in a loop-like configuration to thereby cause data transmission to be effected among the control units through the optical fibers, and an electrical loop transmission path for interconnecting the central control unit and the plurality of local control units by electrical signal conductors in a loop-like configuration to thereby cause data transmission to be effected among the control units through the electrical signal conductors, wherein the central control unit selects at least one of the optical loop transmission path and the electrical loop transmission path to be connected to the signal transmitter means in dependence on predetermined conditions, so that data transmission is conducted between the central control unit and the local control units through the selected loop transmission path.

Multiplex communication system

An information transmitting apparatus includes a transmitting apparatus for transmitting control information; a receiving apparatus for receiving the control information; a transmission line provided between the transmitting apparatus and the receiving apparatus; and a load which operates in response to the output of the receiving apparatus; wherein the transmitting apparatus transmits the control information through the transmission line to the receiving apparatus within a given time period and the receiving apparatus makes the load operative on the basis of the control information received. The receiving apparatus has a circuit for detecting the reception interval of the transmission information from the transmission line and for generating an abnormality signal when that interval becomes a predetermined time or more.

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Katsuta, Japan

Fumio Hamano