Collective wiring system and method of control thereof

• US 5,438,506 A
• Filed: 01/10/1994
• Issued: 08/01/1995
• Est. Priority Date: 02/23/1985
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Matsumoto, Masahiro, Shibata, Takanori, Hasegawa, Akira, Oho, Shigeru, Hirayama, Takeshi, Hamano, Fumio
• Primary Examiner(s): RUGGIERO, JOSEPH F
• Application Number:
  US08/179,540
• Time in Patent Office: 568 Days
• Field of Search: 364/140-147, 364/138, 364/139, 364/425, 364/424.01, 364/424.03, 364/424.05, 364/424.04, 364/178, 364/179, 371/29.1, 340/825.06, 340/825.07, 340/825.15, 361/428, 370/85.1, 370/85.15, 370/100.1, 370/103, 395/275
• US Class Current: 700/9
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

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.

Claims

1. A method of control of a collective wiring system for a motor vehicle in which a central control unit fetches input data representing a status condition and outputs control data via a transmission path to a plurality of terminal control units which control vehicle electrical devices by transmitting said control data thereto, comprising the steps of:

(1) generating control data on the basis of fetched input data representing status conditions and holding the generated control data;

(2) storing in memory a listing of identifiers of terminal control units in an arbitrary predetermined order;

(3) generating addresses of terminal control units in response to the identifiers stored in said memory and in the order in which said identifiers are stored in said memory;

(4) formatting a sequence of messages each including a generated address of a terminal control unit and control data to be sent to the terminal control unit; and

(5) transmitting said sequence of messages periodically via said transmission path to said terminal control units according to the addresses thereof and in the arbitrary order of said listing of identifiers, independent of said generating and holding step (1).

2. A method of control of a collective wiring system according to claim 1, wherein said steps (1) to (3) are performed by said central control unit.

3. A method of control of a collective wiring system according to claim 2, wherein said central control unit includes a memory to hold generated control data and a timer, and wherein said steps (1) and (3) are repeatedly performed after initialization of said memory and said timer.

4. A method of control of a collective wiring system according to claim 1, wherein said central control unit transmits said control data and said terminal control unit returns data including said input data representing a status condition in accordance with the transmitted control data.

5. A method of control of a collective wiring system according to claim 4, wherein said steps (1) and (3) are repeatedly performed each time a signal is transmitted to a certain terminal control unit and a signal has been returned back from said certain terminal control unit, so that said terminal control units are accessed in a predetermined sequence according to said arbitrary predetermined order.

6. A method of control of a collective wiring system according to claim 5, wherein said central control unit has a monitor table for holding said input data representing a status condition and a control table for holding information for controlling a vehicle electrical device.

7. A method of control of a collective wiring system according to claim 6, wherein said central control unit stores information of a status of a vehicle electrical device in said monitor table upon reception of said input data from a terminal control unit, and then reads information stored in said control table and transmits it as control data to said terminal control units.

8. A method of control of a collective wiring system according to claim 5, wherein said central control unit transmits said control data to a next terminal control unit in said predetermined sequence when input data has not been received within a predetermined time from a current terminal control unit in said predetermined sequence.

9. A method of control of a collective wiring system according to claim 1, wherein said central control unit effects the transmission of said control data in parallel with said generation of the control data.

10. A method of control of a collective wiring system according to claim 1, wherein said central control unit controls the transmission and reception of signals between said central control unit and said terminal control units, by way of a communication interface module composed of hardware.

11. A method of control of a collective wiring system according to claim 10, wherein said communication interface module receives control data as a parallel data signal from said central control unit and converts said control data into a serial data signal for transmission.

12. A method of control of a collective wiring system according to claim 11, wherein said communication interface module converts a received serial data signal into a parallel data signal for said central control unit when a serial data signal is received from a terminal control unit, and outputs a further signal to said central control unit representing the fact that a signal from a terminal has been received.

13. A method of control of a collective wiring system according to claim 12, wherein said further signal representing the fact that a signal has been received from a terminal control unit is outputted to an interruption terminal of a digital computer installed in said central control unit.

14. A method of control of a collective wiring system according to claim 13, wherein said communication interface module has a control circuit composed of hardware, and transmission and reception of signals to and from a terminal control unit is controlled by said control circuit.

15. A collective wiring system comprising:

a processing unit including a microprocessor for preparing transmission data;

a plurality of control units which control electrical devices;

a transmission path for transmitting transmission data between said plurality of control units and said processing unit; and

a memory element for storing a scan table of addresses of all of said plurality of control units in an arbitrary predetermined order in which said plurality of control units are to be periodically accessed by said processing unit.

16. A collective wiring system according to claim 15, wherein said microprocessor increments a pointer in said scan table for each transmission data with one of said plurality of control units for indicating an address of a control unit for effecting a next transmission.

17. A collective wiring system according to claim 15, wherein each of said control units has a communication interface module and both the address of each control unit and address of each communication interface module are listed in said scan table stored in said memory element.

18. A collective wiring system according to claim 17, where transmission data passing through said transmission path has a field for the address of each control unit and a field for the address of each communication interface module.