JPH0692215B2 - In-vehicle control system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an on-vehicle control system which is mounted on a vehicle and which connects a plurality of terminal units to a main unit to perform communication for control.

[Conventional technology]

FIG. 2 shows an example of this type of conventional device, 1 is a main unit mounted on a vehicle, and a serial interface 2
The receiving line 4 is connected to the input port side of the serial interface 2 via the photocoupler 3 and the transmitting line 6 is connected to the output port side of the serial interface 2 via the transistor 5. There is.
The serial interface 2 is connected to a control unit 7 including a microcomputer. 8-10 is resistance,
11, 12 are power supplies. 13 is a vehicle-mounted terminal unit,
The serial interface 14 is provided, and the reception line 4 is connected to the output port side of the serial interface 14 via the transistor 15 and the transmission line 6 is connected to the input port side of the serial interface 14 via the photocoupler 16. . Further, the serial interface 14 is connected to a control unit 17 including a microcomputer. 18 ~
20 is a resistor, 21 is a diode, and 22 and 23 are power supplies. Also, 2
Reference numeral 4 is another terminal unit that is also mounted on the vehicle, and has a serial interface 25, the output port side of which is connected to the branch line 4a of the reception line via the transistor 26, and the input port side of which is connected via the photocoupler 27. Is connected to the branch line 6a of the transmission line 6. In addition, the serial interface 25 includes a control unit composed of a microcomputer.
28 is connected. 29 to 31 are resistors, 32 is a diode,
33 and 34 are power supplies. The terminal unit is also provided in the same manner.

Next, the operation of the above configuration will be described. For example, when performing an operation such as changing the frequency of a car radio, an operation command is issued from the control unit 7, and this command is input to the terminal unit 13 from the transmission line 6 via the serial interface 2 and the transistor 5. This input is applied to the control unit 17 via the photocoupler 16 and the serial interface 14 of the terminal unit 13, and the control unit 17 drives and controls the vehicle-mounted device so that the operation according to the command is performed. Then, when the operation according to the instruction is performed, a counter signal is output from the control unit 17 to the reception line 4 via the serial interface 14 and the transistor 15, and the output is the photocoupler 3 and the serial interface 2 of the main unit 1. It is sent to the control unit 7 via the and the operation is confirmed. When performing other operations, signals are exchanged with the terminal unit 24, for example. Identification of each terminal unit is performed by including a code signal in the output of the main unit 1.

In the above-mentioned conventional device, the transmission line 6 and the reception line 4 are provided with the branch lines 4a and 6a. On the transmission side of the main unit 1, the photocouplers 16 and 27 electrically connect the units 1, 13 and 24 to each other. Be separated. On the other hand, on the receiving side, the main unit 1 and the terminal units 13 and 24 are electrically separated from each other by the photocoupler 3, but the terminal units 13 and 24 are not electrically separated from each other. In this case, when the ground level of one terminal unit fluctuates, the ground level of the other terminal unit also fluctuates, which causes noise and malfunction.

Further, FIG. 3 shows another conventional device. In the main unit 1, a photo coupler 35 is connected to an input port different from the input port to which the photo coupler 3 of the serial interface 2 is connected. It is connected to the output side of the terminal unit 24 via the line 36. A transistor 37 is connected to an output port different from the output port to which the transistor 5 of the serial interface 2 is connected,
The transistor 37 is connected to the terminal unit 24 via the transmission line 38.
Connected to the input side of. Note that 39 and 40 are power supplies and 41 to 43 are resistors. Further, in the terminal unit 13, the resistor 9 is moved from the main unit 1, and in the main unit 1, the resistor 9 is moved.
18 has been moved from terminal unit 13 and terminal unit 24
In, a resistor 44 is provided. The other structure is similar to that of FIG.

In the conventional device shown in FIG. 3, the operation on the side of the terminal unit 13 is the same as that of FIG. 2, and also on the side of the terminal unit 24, the photocoupler 35, the transistor 37 and the transmission / reception line 3 are provided.
The functions of 6,38 are the same as those of the terminal unit 13 side. In such a conventional device, the transmission lines 6 and 38 and the reception lines 4 and 36 are provided for each terminal unit 13 and 24, and these are electrically separated by the photocouplers 3, 16, 27 and 35. Therefore, the fluctuation of the power supply or the ground level of one terminal unit does not affect the other terminal unit, and it is possible to prevent the occurrence of noise or malfunction. However, the number of input ports and output ports of the serial interface 2 in the main unit 1 increases,
The configuration and control process became complicated.

[Problems to be Solved by the Invention]

As described above, in the conventional device, when the transmission / reception line is branched, the terminal units are not electrically separated from each other and noise or malfunction occurs. Further, if a transmission / reception line is provided for each terminal unit, noise and malfunction can be prevented, but there is a problem that the configuration and control processing become complicated.

The present invention has been made to solve the above problems, and an object thereof is to obtain an in-vehicle control system capable of preventing noise and malfunction and simplifying the configuration and control processing. And

[Means for Solving the Problems]

The vehicle-mounted control system according to the present invention transmits a control signal to each terminal unit from an individual transmission unit via an individual transmission line, and sends a reply signal from each terminal unit via an individual reception line to an individual reception line. There is provided a main unit which receives by a photo coupler and which is connected to each transmission unit and each photo coupler to be connected to a serial interface.

[Work]

In the present invention, communication between the main unit and each terminal unit is performed using separate transmission lines and reception lines, and the photo couplers as the transmission units and the reception units in the main unit are connected to one, respectively. Connected to the serial interface.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
The figure shows the configuration of the in-vehicle control system according to this embodiment,
Reference numeral 45 is an AND circuit which is a synthesizing means for inputting the outputs of the photocouplers 3 and 35, and the output thereof is the serial interface 2
Input to the input port of. Reference numeral 46 is a transistor, which is a branching means, the output side of which is connected to the respective transistors 5 and 37 constituting the transmitting section, and the input side thereof is connected to the output port of the serial interface 2. Also, 47 and 48 are resistors and 49
Is the power supply. Other configurations are the same as those in FIG.

Next, the operation of the above configuration will be described. The control signal issued from the control unit 7 is given from the output port of the serial interface 2 to each of the transistors 5 and 37 which is a transmission unit via the transistor 46, and further to the photo couplers 16 and 27 via the transmission lines 6 and 38. Given. Further, the control signal is given to the control units 17 and 28 via the serial interfaces 14 and 25, but the control signal also includes the code signal, and only a specific control unit, for example, the control unit 17 operates. This controller
The in-vehicle device is driven and controlled by the operation of 17, and in response to this, a reply number is sent from the control unit 17 via the serial interface 14, the transistor 15, and the reception line 4 to the photo coupler 3
Given to. Therefore, the output of the photocoupler 3 changes from high to low, and the output of the AND circuit 45 also changes from high to low. This signal is applied to the control unit 7 via the input port of the serial interface 2 to check the operation. .

In the above embodiment, since the transmission / reception lines 4, 6, 36, 38 are provided for each terminal unit 13, 24, the units 1, 13, 24 are electrically separated from each other, and noise and malfunction are prevented. It Also, the transistors 5 and 37 and the photocouplers 3 and 35 are combined into a single serial interface 2
Since it is connected to the serial interface, only one input port and one output port are required for the serial interface, which simplifies the configuration and control processing.

In the above embodiment, the terminal unit 13,244 is used for convenience of explanation.
However, other terminal units have similar configurations and operations.

〔The invention's effect〕

As described above, according to the present invention, by providing a transmission / reception line for each terminal unit, the units are electrically separated from each other completely, mutual influences of power supply fluctuations and ground level fluctuations are eliminated, and noise and malfunction are prevented. To be done. Moreover, in the main unit, the number of the photo couplers as the transmitting unit and the receiving unit is respectively one and is connected to the serial interface, so that only one input port and one output port are required, which simplifies the configuration and control processing. Become.

[Brief description of drawings]

FIG. 1 is a block diagram of the device of the present invention, and FIGS. 2 and 3 are block diagrams of a conventional device. 1 ... Main unit, 2 ... Serial interface, 3,16,27,35 ... Photo coupler, 4,36 ... Reception line, 5,37,46 ... Transistor, 6,38 ... Transmission line, 1
3,24 …… Terminal unit, 45 …… and circuit. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A plurality of units mounted on a vehicle, having a photo coupler on the receiving side, driving and controlling an in-vehicle device according to a control signal received through the photo coupler, and returning a result of the driving control. A control signal is transmitted to each of the photocouplers provided in the terminal unit and the vehicle and provided in the plurality of terminal units via a separate transmission line, and the reply signals from the plurality of terminal units are individually transmitted. A main unit for receiving by a separate photocoupler via a reception line is provided, and the main unit controls the plurality of terminal units, and sends and receives signals to and from the control unit and the plurality of units. Connected to the output port of this serial interface and the serial interface with one output port and one input port Branching means for branching a transmission line to create the individual transmission line; and combining means for combining the output lines of the photocouplers provided in the main unit into one and connecting to the input port of the serial interface. An in-vehicle control system comprising: