JPH01120141A - Control unit communication line abnormality detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a communication line abnormality detection device in a parallel interface type control unit communication structure.

<Prior Art> In recent years, many automobile control devices using microcomputers have come into use.

As shown in FIG. 2, as a communication structure between control units of such a control device, there is a parallel interface type communication structure in which digital signals are transmitted in parallel from a transmitting side control unit 1 to a receiving side control unit 2. .

<Problems to be Solved by the Invention> However, in such a parallel interface type communication structure, in the case of communication in only one direction, it is difficult to determine whether the transmitted signal and the received signal match. If it is impossible to judge, and there is an abnormality such as a short or disconnection in the communication line, the transmitted signal and the received signal will differ, making it impossible to perform accurate control and lacking reliability. It was something.

In view of the above-mentioned conventional circumstances, the present invention provides a control unit communication system that improves reliability by easily determining whether or not a transmitted signal and a received signal match. The purpose of the present invention is to provide a line abnormality detection device.

Means for Solving Problems> Therefore, as shown in FIG. 1, in the communication structure between control units of the parallel interface type, the present invention has the following advantages: means for alternately outputting the signals to the receiving side control unit;
The configuration includes means for counting the number of times of the h signal and all Lo- signals, and means for determining whether there is an abnormality in the communication line based on the counted number of times.

(Function) In this configuration, a signal in which all the communication lines are all High and a signal where all are Low are alternately output to the receiving control unit, and when the receiving control unit receives both signals a predetermined number of times or more, there is no abnormality. However, if it is not received a predetermined number of times or more, it is determined that there is an abnormality.

<Example> Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the present invention, in the parallel interface type inter-control unit communication structure, as shown in FIG.
B, C: means for alternately outputting all High signals and all Low signals to the receiving side control unit 2; means for counting the respective number of times of the all High signals and all Lo- signals; and means for determining an abnormality in the communication line based on the communication line.

That is, communication lines A and B are connected from the transmitter control unit 1 to
, C, as shown in FIG. 3, all High signals and all LO- signals are alternately outputted together with the control signals.

The counting means and determining means provided in the receiving side control unit 2 operate as shown in the following flowchart.

In the counting routine that is executed at regular intervals (for example, every 10 m5) in Fig. 4, all H
Determine whether the signal is high and all the signals are low, respectively.
If so, proceed to S3 and 4 and add 1 to the previous count number.
Add times and add them one after another.

In the determination routine shown in FIG. 5 that is executed at regular intervals, it is first determined in Sl whether flag F is set to 1 or not. This flag F is initially set to 0 in advance when power is turned on to the control unit.

Therefore, in the first stage, 82 is executed after Sl. In this S2, it is determined whether the count number of the Lgh counter has reached a predetermined OK level as shown in FIG. It is determined whether or not the number has reached the predetermined OK level as shown in FIG.
If the level has been reached, it is determined to be normal. On the other hand, if the OK level has not been reached in S2 and 33,
Proceeding to S5, flag F is set to 1, and if at least one of the count number of the High counter and the count number of the Lo-counter has not reached the OK level (see Figure 6), an abnormality is determined in S6. . Then, in S5, when flag F is set to 1, flag F of Sl
After determining whether or not is set to 1, processing beyond S32 to S6 is performed.

As described above, if all High and all Lo- signals are not received for a predetermined number of times or more at regular intervals, it is determined that there is an abnormality, thereby easily determining that an abnormality such as a short or disconnection of the communication line has occurred. It is possible to prevent the transmitted signal from being different from the received signal, to perform accurate control, and to improve reliability.

It should be noted that the above transmission line abnormality determination can be applied to, for example, an automobile control device that transmits a limited number of control signals such as a signal during an autotransmission shift, whose time and frequency can be predicted.

Also, all High and all Low signals are sent, and the number of times these signals are sent is used as a criterion, so all High signals are sent as control signals.
High and all Low signals are excluded.

<Effects of the Invention> As explained above, according to the present invention, in a parallel interface type communication structure in which digital signals are transmitted from a transmitting side control unit to a receiving side control unit in parallel, the communication line is The occurrence of abnormalities such as short circuits and disconnections can be easily detected.
It is possible to eliminate the situation where accurate control cannot be performed due to a difference between the transmitted signal and the received signal, and the reliability of communication can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a control unit communication line abnormality detection device according to the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of the same device, and FIG. 3 explains the operation of the same embodiment. FIG. 4 and FIG. 5 are a flowchart explaining the operation of the above embodiment, and FIG.
The figure shows abnormality and normality levels of communication lines.

Claims (1)

[Claims] In a parallel interface type inter-control unit communication structure, means for alternately outputting all High signals and all Low signals from the transmitting side control unit to the receiving side control unit, and the all high signals and all low signals respectively. 1. An abnormality detection device for a control unit communication line, comprising: means for counting the number of times, and means for determining an abnormality of the communication line based on the counted number of times.