JPH04345337A - On-vehicle multiplex transmission controller - Google Patents

Abstract

PURPOSE:To save number of transmission lines and to simplify the transmission changeover device. CONSTITUTION:Two of three transmission lines 5-7 being three multiplex transmission lines are used to be connected to a transmission controller 1 via a transmission changeover device 4 and a bus transceiver 2 and the remaining one transmission line is used as a standby line and when the transmission control means detects a fault with a data from the transmission lines in use and the fault is informed to an error detection means 3, from which a transmission line switching signal is sent to a transmission line changeover device 4, which selects the normal standby transmission line from a faulty transmission line. Thus, number of the plural multiplex transmission lines is saved and the transmission line changeover device is simplified.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle multiplex transmission control device for controlling multiplex transmission between a plurality of electronic control devices mounted on an automobile.

0002

2. Description of the Related Art FIG. 3 is a block diagram showing the configuration of a conventional vehicle multiplex transmission control device. The vehicle multiplex transmission control device shown in FIG. , a bus transceiver 2 consisting of transmitters TX1, TX2, receivers RX1, RX2, error detection means 3 for detecting errors in the transmission line and sending out a transmission line switching signal, and duplex double-wire transmission lines 14, 15. It is composed of.

Next, the operation will be explained. As an example, a case will be described in which the double-wire multiplex transmission line 14 is used for transmission and the double-wire multiplex transmission line 15 is used for backup.

Two contacts a+, a in the transmission line switching device 4
- are connected to double-wire multiplex transmission lines a+ and a-, respectively, and when transmission is normal, data is transmitted from the double-wire multiplex transmission line 14 via the transmission line switching device 4 and the receivers RX1 and RX2 of the bus transceiver 2. It is transmitted to the control means 1.

However, if the double-wire multiplex transmission line 14 is short-circuited with another, the voltage level of the double-wire multiplex transmission line 11 remains constant, so the error detection means 3 detects an abnormality in the double-wire multiplex transmission line 14. Then, a transmission line switching signal is output to the transmission line switching device 4.

[0006] As a result, the transmission line switching device 4 switches the contact point to b.
Switch to + and b- sides. As a result, data can be transmitted from the double-wire multiplex transmission path 15 to the transmission control device 1 side.

[0007]

[Problem to be Solved by the Invention] Since the conventional vehicle multiplex transmission control device that takes measures against transmission line abnormalities is configured as described above, only two transmission lines are used during data transmission. Even though it does not work, it has to be sent over four double-wire multiplex transmission lines.

Therefore, as the number of transmission lines increases, the number of switching contacts in the transmission line switching device 4 also increases as the number of double-wire multiple transmission lines increases.

The present invention has been made to solve the above-mentioned problems, and provides a multiplex transmission control device for a vehicle that can reduce the number of double-wire multiplexed transmission lines and also simplify the configuration of the transmission line switching device. The purpose is to obtain.

0010

[Means for Solving the Problems] A multiplex transmission control device for a vehicle according to the present invention includes three double-wire multiplex transmission lines, and three double-wire multiplex transmission lines.
A transmission control means that connects to the main double-wire multiplex transmission line to control data reception and transmission, and an error detection means that detects an abnormality in the double-wire multiplex transmission line through this transmission control means and outputs a transmission line switching signal. and a transmission line switching device that switches the double-wire multiplex transmission line using a transmission line switching signal.

[0011]

[Operation] The transmission control means in this invention receives data from three double-wire multiplex transmission lines and controls the transmission to an electronic control device, and receives data from three double-wire multiplex transmission lines by this transmission control device. If there is an abnormality in the data from the transmission line, the error detection means detects it and sends a transmission line switching signal to the transmission line switching device. Disconnect the transmission line and switch to a normal transmission line.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the vehicle multiplex transmission control apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment. In FIG. 1, the same parts as those in FIG. 3 will be described with the same reference numerals.

In FIG. 1, reference numeral 1 denotes a transmission control means that is connected to a microcomputer (not shown in FIG. 1) that controls an electronic control device and performs data transmission and reception. Data from the transmission lines 5, 6, and 7 of the three double-wire multiplex transmission lines are inputted through the transmission line switching device 4 and the receivers RX1 and RX2 of the bus transceiver 2.

Of the three transmission lines 5, 6, and 7, two are used for transmission, and the remaining one is used as a backup.

Three double-wire multiplex transmission lines 5, 6,
7 are connected to contacts A, B, and C of the transmission line switching device 4, respectively, and the contacts A, B, and C of the transmission line switching device 4 are connected to each other by a transmission line switching signal from the error detection means 3. It has become so.

A bus transceiver 2 is connected between the transmission control means 1 and the transmission line switching device 4. Bus transceiver 2 is transmitter TX1, TX2, receiver RX
1, RX2, and the data is transmitted from the transmission control means 1 to the transmission lines 5, 6, and 7 of the three double-wire multiplex transmission lines through the transmitters TX1 and TX2, and When receiving data from transmission lines 5, 6, and 7 of the multiplex transmission path, the data is received via receivers RX1 and RX2.

[0017] The error detection means 3 includes the transmission control means 1
3 by detecting the level of data input to the
It is designed to detect an abnormality such as a short circuit or disconnection in any of the double-wire multiplex transmission lines 5, 6, and 7, and when this abnormality is detected, the transmission line switching signal is sent to switch the transmission line as described above. It is designed to be output to device 4.

FIG. 2 is a system configuration diagram showing an example of a multiplex transmission system using the vehicle multiplex transmission control device of the present invention. In FIG. 2, explanation will be given assuming that among the three transmission lines 5, 6, and 7 of the above-mentioned double-wire multiplex transmission line, transmission lines 5 and 6 are currently used, and transmission line 7 is used as a backup. Proceed.

Reference numerals 8, 9, and 10 are electronic control devices controlled by the microcomputer, respectively, and these electronic control devices 8, 9, and 10 include multiplex transmission control devices 11, 12, and 12, respectively, shown in FIG. 13 is installed. As shown in FIG. 1, each of the multiplex transmission control devices 11, 12, and 13 is connected to the transmission lines 5, 6, and 7 of three double-wire multiplex transmission lines.

Next, the operation will be explained with reference to FIGS. 1 and 2. If there is no abnormality such as disconnection or short circuit in the transmission lines 5 and 6, contacts A and B of the transmission line switching device 4 are connected, and the data on the transmission lines 5 and 6 is transferred to the transmission switching device 4.
contacts A, B and receiver RX of bus transceiver 2
1 and RX2, the signal is taken into the transmission control means 1, and is transmitted from the transmission control means 1 to the electronic control devices 8, 9, and 10 via the microcomputer. In other words, normal transmission is performed.

Next, a case where the transmission line becomes abnormal will be explained. If the transmission line 5 is short-circuited to the power supply or ground, the error detection means 3 detects the transmission line 5 through the transmission control means 1 of the multiplex transmission control devices 11, 12, 13 mounted on each electronic control device 8, 9, 10. Detects when the voltage level becomes constant and considers it a short circuit.

Further, when the transmission line 5 is disconnected, each transmission control means 1 of the multiplex transmission control devices 11, 12, 13 transfers data from the transmission line 6 to the receiver R of the bus transceiver 2.
Since only the data through X2 is received, the transmission control device 1 considers that the transmission line 5 is broken, and notifies the error detection means 3.

[0023] With this, the error detection means 3 detects the transmission line 5.
is determined to be abnormal, and sends a transmission line switching signal to the transmission line switching device 4.

Transmission line switching device 4, which has received the transmission line switching signal, switches contact A to contact C. As a result, the abnormal transmission line 5 is disconnected and a spare transmission line 7 is connected in its place, and this transmission line 7 is used to transmit data to each electronic control device 8, 9, 10. Can be done.

[0025] Furthermore, if the transmission lines 5 and 6 are short-circuited,
The transmission control means 1 of the multiplex transmission control devices 11, 12, and 13 installed in each electronic control device 8, 9, and 10 is configured so that the transmission line It is detected that there is a short circuit between 5 and 6, and the transmission control device 1 notifies the error detection means 3.

[0026] With this, the error detection means 3 detects the transmission line 5.
It detects that there is a short circuit between and 6, and outputs a transmission line switching signal to the transmission line switching device 4. As a result, the transmission line switching device 4 disconnects the contact B and connects it to the contact C.

Accordingly, by using the short-circuited transmission lines 5 and 6 and the transmission line 7, it becomes possible to transmit data to the electronic control device.

[0028]

As described above, according to the present invention, three double-wire multiplex transmission lines are used, an abnormality in each of the transmission lines is detected by the transmission control means, and when an abnormality is detected, the error detection means is notified. Since the configuration is configured so that the transmission line switching device performs transmission line switching control, the number of transmission lines is reduced and
This has the effect of simplifying the transmission switching device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a vehicle multiplex transmission control device according to an embodiment of the present invention.

FIG. 2 is a system configuration diagram of a double-track multiplex transmission system using the same vehicle multiplex transmission control device.

FIG. 3 is a block diagram showing the configuration of a conventional vehicle multiplex transmission control device.

[Explanation of symbols]

1 Transmission control means 2 Bus transceiver 3 Error detection means 4 Transmission line switching device 5 Transmission line 6 Transmission line 7 Transmission line 8 Electronic control device 9 Electronic control device 10 Electronic control device 11 Vehicle multiplex transmission control device 12 Vehicle multiplex transmission control device 13 Vehicle multiplex transmission control device

Claims (1)

[Claims] 1. A transmission control means that is mounted on an electronic control device connected to three double-wire multiplex transmission lines and controls transmission and reception of transmission data, and a transmission control means that detects an abnormality in the double-wire multiplex transmission line. A multiplex transmission control device for a vehicle, comprising: an error detection means for detecting an error through the transmission line and outputting a transmission line switching signal; and a transmission line switching device for switching the double-wire multiplex transmission line based on the transmission line switching signal.