JPH05227259A - Fault diagnostic device for multiplex transmitter - Google Patents

Abstract

PURPOSE:To obtain the fault diagnostic equipment for a transmission unit in the multiplex transmission system in which plural transmission units are connected to a common transmission line. CONSTITUTION:A transmission address space is used in common for an address of a data signal and an address for a fault diagnostic signal and a fault diagnostic device 5 is connected to a transmission line 6 separately from transmission units 2, 3, 4. A fault diagnostic signal is sent from the transmission units 2, 3, 4 or the fault diagnostic device 5 by the fault diagnostic address, or the fault diagnostic signal received by the transmission units 2, 3, 4 is looped back as it is or with a prescribed relation of them and the fault diagnostic signal received by the fault diagnostic device 5 is analyzed to diagnose a fault of the system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosis device for improving the reliability and maintainability of a multiplex transmission device,
In particular, the present invention relates to a failure diagnosing device for a multiplex transmission device which is composed of a large number of transmission units, transmits / receives data in synchronization with a clock, and counts the clock to determine an address.

[0002]

2. Description of the Related Art In a conventional general multiplex transmission device,
The transmission is performed in units of frames in which an address part indicating the destination address is added to the data to be transmitted. A frame is transmitted from the transmitting side, and the receiving side takes in data whose frame address matches its own address.

In this system, when data is received by the receiving side, the receiving side performs various checks and returns a reply based on the result. Since the transmitting side receives this reply and performs the confirmation operation, it is possible to confirm that the receiving side has received the data, which also serves as a failure diagnosis. On the transmitting side, the reliability is improved by performing processing such as retransmission if necessary. FIG. 5 shows an example of the format of a transmission frame, and FIG. 6 shows an example of a procedure for returning a reply.

The multiplex transmission of this system is disadvantageous in that the transmission efficiency of the net data to be transmitted is low because a lot of information such as an address portion is included in the frame. Especially 1
This drawback is significant when the length of data transmitted in a frame is short.

A multiplex transmission system which eliminates this drawback and maintains high transmission efficiency even when transmitting data in 1-bit units is also used. For example, the present inventor has previously described Japanese Patent Application No. 62-131.
The method proposed in 882 is a typical example. The system configuration of this system is shown in FIG. In this figure, there is one transmitting station and one receiving station, but it is generally composed of many stations.

The clock shown in FIG. 8 is sent from the control device. Data transmission is performed for each bit clock, and more specifically, data transmission is performed during the inactive period of the bit clock. An address is required to identify the transmission position. The address is determined by counting the number of bit clocks. That is, the transmitting station transmits data at the clock position determined to be its own address by the above method, and the receiving station similarly receives the data at the clock position determined to be its own address.

In this transmission method, most of the frame is used for data, so that the data transmission efficiency is high. In addition, it is possible to perform arbitrary transmission in 1-bit units.
It has many features, such as being able to send to multiple locations at the same time by sharing the same address. Moreover, it is inexpensive because it is easy to control.

However, in this method, a reply for confirmation is not made unless some means is added. There is a defect that the sender cannot confirm that the other party has received. For systems that require high reliability for this,
It is necessary to add a function for detecting and diagnosing a failure to compensate for this defect. However, since the transmission method itself is extremely simple and inexpensive, the use of a commonly used fault diagnosis detection method is relatively expensive. Therefore, in the past, simple but insufficient fault diagnosis detection, such as confirmation that a signal is flowing in the transmission line, has been used.

[0009]

From the above, in order to use a simple and inexpensive multiplex transmission system in a system that requires high reliability, a simple and inexpensive fault diagnosing device with high reliability is constructed. It is necessary to. The present invention aims to solve this problem. It should be noted that in order to carry out a failure diagnosis, it is not always necessary to confirm the reception of the other party who sent the data. Rather, it is desirable to be able to monitor failure information of the entire system in one place. The present invention aims to easily meet this demand.

[0010]

In order to solve the above problems, the present invention provides a multiplex transmission system in which a transmission address space is shared by a data signal address and a fault diagnosis signal address, and a transmission unit is generally used. The failure diagnosis signal is transmitted at a failure diagnosis address independent of the data transmission address, and the failure diagnosis device receives the failure diagnosis signal,
Fault diagnosis is performed by the signal.

Further, the failure diagnosis device transmits a failure diagnosis test signal, the transmission unit receives the test signal, and transmits the signal or a signal having a fixed relationship with the signal as a failure diagnosis signal to cause a failure. The diagnostic device receives the fault diagnostic signal and compares the test signal with the test signal to perform a fault diagnostic.

When the transmission unit B receives the data signal transmitted from the transmission unit A, the transmission unit B uses the data signal transmitted from the transmission unit A or a signal having a certain relationship with the data signal for failure diagnosis. The data is transmitted as a signal, and the failure diagnosis device receives the data signal and the failure diagnosis signal and compares the two signals to perform failure diagnosis.

Further, the transmission unit transmits a signal which is the same as or has a constant relationship with the data signal transmitted by itself, as a fault diagnostic signal, and the fault diagnostic device receives the data signal and the fault diagnostic signal. , Fault diagnosis is performed by comparing both signals.

[0014]

[First Embodiment] FIG. 1 shows a first embodiment of a data transmission system according to the present invention, in which a control unit 1, a transmission unit 2 for transmission, transmission units 3 and 4 for reception, and a failure diagnosis apparatus 5 are used. Configured, transmission line 6
Are connected to each other by. Here, a case where one transmission unit for transmission and two transmission units for reception are shown is shown, but in general, a large number of transmission units are connected. There is also a variation in which a plurality of functions are accommodated in one case and integrated. For example, a transmission unit having both a transmission function and a reception function, or a transmission unit that also serves as a control unit is possible.

The structure and operation of the control unit 1 and the transmission unit 2 for transmission are not peculiar to the present invention. Is the same as However, in the system of the previous application, the clock signal also serves as the power supply, but the present invention is also applied to the system in which the clock signal does not serve as the power supply. Basically, any transmission system can be applied as long as the transmission bits can be addressed in bit units.

The operation principle of the receiving transmission unit is the same as that of the receiving station of the previous application method, but a function for transmitting a failure diagnosis signal is added.

The structure of the receiving transmission unit is shown in FIG.
The configuration and operation of the transmission control units 11 and 21 are the same as those of the previous application, but the address units are data signal address units 12 and 22 and failure diagnostic signal addresses 14 and 24, respectively.
Have a set. The data signal address part 12 of the reception transmission unit 3 determines that the address is from 1 to 8 when the address is 1 to 8 and takes in the data signal transmitted from the transmission transmission unit, and the data reception part 13 receives the data signal. Use the data. Similarly, in the reception transmission unit 4, the data reception address section 22 determines the addresses 9 to 32 as its own address, and takes in the transmitted data signal and uses it in the data reception section 23. Therefore, in the transmission unit for transmission, addresses 1 to 32 are assigned and data signals are transmitted.

The role of the failure diagnosis device 5 in this embodiment is as follows.
It is to monitor that the receiving transmission units 3 and 4 are operating normally. The addresses for the failure diagnosis signals of the reception transmission units 3 and 4 are determined by the failure diagnosis signal address sections 14 and 24 at 33 and 34, respectively. When the addresses match, the transmission control units 11 and 21 transmit the information of the failure diagnosis signal generating unit.

The failure diagnosis signal in this embodiment is the same signal as the active signal of the data signal. That is, the failure diagnosis signal generator of the reception transmission unit monitors the state of the own unit and generates an active signal when the own unit is determined to be normal and an inactive signal when the unit is determined to be not normal. .. When an overall failure of the reception transmission unit occurs, transmission of the failure diagnosis signal itself becomes impossible, but at this time, it means that an inactive signal is transmitted. In addition, as a simple method, the failure diagnosis signal generator can always generate an active signal. Even at this time, when the receiving transmission unit is totally out of order, it becomes similar to transmitting an inactive signal, so that it can serve as a failure diagnosis signal.

The configuration of the failure diagnosis device 5 is shown in FIG. The transmission control unit 31 has the same function as the transmission unit, and acts as a reception function on the transmission path. The addresses of the address portion are 33 and 34, and the failure diagnosis signal transmitted by the reception transmission units 3 and 4 is received. The failure diagnosis signal is determined by the failure diagnosis unit. In this embodiment, when the signal is an active signal, the receiving transmission unit is determined to be normal, and when the signal is inactive, the receiving transmission unit is determined to be defective. The result of diagnosis is the fault diagnosis device 5
Is displayed / warned or is sent to the outside.

In this embodiment, the failure diagnosing signal output from each receiving unit has one bit each, but it may have a plurality of bits. At this time, since a plurality of failure factors can be distinguished and transmitted, the failure diagnosis device can perform more detailed diagnosis.

In the present invention, as shown in this embodiment, it is important that the data transmission address and the failure diagnosis signal address are independently assigned.

What would happen if this were not assigned an independent address? The address allocation method in that case is as follows, for example. Similarly, the data transmission address of the reception transmission unit 3 is 1
From 8 to 8. Further, the address of the failure diagnosis signal will be assigned to 9. In this case, the data transmission address of the reception transmission unit 4 is assigned from 10 to 33, and the address of the failure diagnosis signal is 34.
Assigned to. Correspondingly, the transmission addresses of the transmission unit for transmission 2 are also 1 to 8 and 10 to 33. The reception addresses of the failure diagnosis signal of the failure diagnosis device are 9 and 34.
Becomes It can be seen that the allocation of this address is complicated and wasteful compared to this embodiment.

In this example, since the number of transmission units is small, the degree of complexity is small. However, when the number of transmission units is large and the combination of data points is complicated, the difference is large and the system cost is also greatly different. In addition, the ease of maintenance and the ease of changes such as increasing or decreasing points will also have a great impact.

Further, depending on the equipment connected to the transmission unit, there are restrictions on the allocation of addresses, and some cannot freely set addresses. In such a case, it is necessary to assign an address according to the restrictions on the address of the connected device.

Although the address for data transmission and the address of the fault diagnosis signal have separate address parts so that they can be set independently, the addresses themselves are not particularly distinguished. Since a single address space is allocated, how to allocate the data transmission address and the failure diagnostic signal address is arbitrary. This is also a feature of the present invention. The number of transmission data and the number of transmission units can be determined within the frame of the total address space without being restricted by the address.
The flexibility of the transmission system configuration is increased.

[0027]

Second Embodiment Next, a second embodiment of the present invention will be shown. The system configuration, the number of transmission data points, and the address allocation are
This is the same as in the first embodiment.

In this embodiment, the failure diagnosis device 5 transmits a failure diagnosis test signal. There are cases where a plurality of types of test signals are required, but in this embodiment, one type of test signal that is common to all transmission units is used.
In the case of a shared signal, transmission may be performed once with one address, and multiple units can receive at the same address at the same time. The address of this test signal is set to 33.

The structure of the receiving transmission unit is the same as that of FIG. However, the failure diagnosis signal address has two of 33 and 34 in the reception transmission unit 3, and has two of 33 and 34 in the reception transmission unit 4. Address 34
Similarly to the first embodiment, 35 and 35 transmit a failure diagnosis signal. The address 33 is used to receive the test signal for failure diagnosis.

Further, in this embodiment, not only the receiving transmission unit but also the transmitting transmission unit 2 is diagnosed. The structure of the transmission unit 2 for transmission is shown in FIG. Transmission control unit 4
The function of 1 is the same as that of the transmission control unit 11 of the reception transmission unit. The address section 42 has an address for transmission data and is 1 to 32. The data transmission unit 43 creates a transmission signal or fetches it from the outside, and transmits the data at a predetermined address. The configuration of the address portion 44 of the failure diagnosis signal is the same as the address portion of the reception transmission unit, and has an address 33 for receiving the failure diagnosis test signal and an address 36 for transmitting the failure diagnosis signal.

The failure diagnosis device 5 in the second embodiment has the same structure as that of the first embodiment, but the transmission control section 31 also has a transmission function. The address section 32 has an address 33 for transmitting a test signal for failure diagnosis and addresses 34 to 36 for receiving a signal for failure diagnosis. The failure diagnosis unit 33
It has the function of fault diagnostic test signal generation. In the second embodiment, the failure diagnosis test signal is a signal which repeats ON and OFF at a constant cycle, and is transmitted at the address 33.

Each transmission unit takes in the test signal, returns it as its own failure diagnosis signal, and transmits it. In this embodiment, the test signal is returned as it is as a failure diagnosis signal, but it may be converted into a signal having a constant relationship with the test signal and returned, for example, by inverting and returning 0 and 1 of the signal. .. This failure diagnosis signal is transmitted at addresses 34 to 36 according to the address of each transmission unit.

In the second embodiment, the fault diagnostic device 5 takes in the fault diagnostic signal and returns the test signal as it is in the transmission unit. Therefore, the fault diagnostic device determines the test transmitted by itself. If the signal and the returned failure diagnosis signal match, it is determined to be normal, and if they do not match, it is determined to be a failure. However, in the transmission system, a transmission error may occur even if there is no failure, resulting in a temporary mismatch. Therefore, it is often necessary to perform processing such as determining a failure with continuous mismatches rather than simple mismatches. This is also true for the first embodiment.

The processing of the failure diagnosis result is similar to that of the first embodiment. In the second embodiment, even when each transmission unit loses the function of receiving the test signal for failure diagnosis and the loopback function, it is judged as a failure, so that more reliable failure diagnosis can be performed. The reason why the address is divided into one for data signal transmission and one for failure diagnosis is the same as in the first embodiment.

In the second embodiment, the address of the normal address space is used as the address of the failure diagnosis test signal. However, when the failure diagnosis test signal is shared by many transmission units, the failure diagnosis test signal is considered to be a special signal different from the general failure diagnosis signal. Therefore, it is conceivable that the test signal for fault diagnosis is assigned to another place when the system of the transmission device uses the system of the previous application. That is, in FIG. 8, a place where the frame clock is inactive is not used and is vacant. The inactive portion of the frame clock is assigned to the transmission of the test signal for fault diagnosis. This method does not lose the generality of the present invention and belongs to the present invention. The same applies when a signal other than the fault diagnostic test signal, which is used for a special purpose of only 1 bit, is assigned to an inactive portion of the frame clock.

This second embodiment can be used in combination with the first embodiment.

Example 3

Next, a third embodiment will be described. First
And the second embodiment is characterized in that it is simple and therefore cheap to implement. However, the degree of reliability required for multiplex transmission systems varies. There are times when high reliability is required even if the cost increases slightly. This third
And the fourth embodiment described below are effective methods in such a case. It is conceivable that these embodiments are used in combination with the first and second embodiments, and that they are applied to particularly required portions.

The configuration of the third embodiment is also the same as that of FIG.
The feature of the third embodiment is that the data signal to be transmitted is used as a test signal for failure diagnosis. Here, a case where data is transmitted from the transmission unit 2 for transmission to the transmission unit 3 for reception will be described as an example. The configurations of the transmission unit 2 for transmission and the transmission unit 3 for reception are similar to those of FIGS. 4 and 2, and 8-bit data is transmitted from the transmission unit 2 for transmission to the transmission unit 3 for reception by using addresses 1 to 8. I am sending.

In the transmission unit 3 for receiving and transmitting, the received data signal is also fetched into the failure diagnosis signal generating section, and the data is returned as a failure diagnosis signal. Also in this case, not only the return signal, but also a failure diagnosis signal having a fixed relationship with the received data, such as being inverted, may be created.

In this case, if the received data is used as all failure diagnosis signals, eight failure diagnosis signal addresses are required. 41 to 48 are assigned as this address. Therefore, this failure diagnosis signal is transmitted at addresses 41 to 48.

In the failure diagnosis device 5, the address unit 3
2 has two parts, one takes in the data signals of addresses 1 to 8 transmitted from the transmission unit for transmission. The other one is to take in the failure diagnosis signal at addresses 40 to 48. The failure diagnosing section compares the corresponding bits of these two types of signals, and if they match, determines normal, and if they do not match, determines failure. In making this comparison, the same consideration as in the second embodiment is applied. The same applies to the use of diagnostic results.

The feature of the third embodiment is that it is possible to perform a failure diagnosis for each point of the data signal with respect to the reception transmission unit, which is a detailed diagnosis. However, when the data signal is folded back in the reception transmission unit, the range to be diagnosed differs depending on where it is folded back. In order to make the diagnosis effective for each point, it is necessary to take a folding route including an individual circuit for each point.

The third embodiment is used as a modification of the second embodiment for the same purpose as the second embodiment, in addition to being used for fine-grained failure diagnosis for each point. You can That is, the data signal transmitted from the transmission unit for transmission is used for the same purpose as the test signal for failure diagnosis of the second embodiment.

[0044]

[Embodiment 4] The third embodiment is capable of finely diagnosing a failure at each point, but cannot be applied to diagnosis of a transmission unit for transmission. That is, the transmission unit for transmission has failed,
This is because even if an abnormality occurs in the transmission signal of the transmission unit, if the reception transmission device and the transmission path are normal, the signals will match in the diagnosis of the failure diagnosis device. However, if the transmission signal itself has a specific property, it is possible to make a diagnosis by using that property. For example, if the transmission signal from the transmission unit for transmission is a signal that turns on and off at a constant cycle, it is possible to determine the failure.

By using the fourth embodiment, the versatility can be given to the diagnosis of the transmission unit for transmission.

The structure of the transmission unit for transmission in the fourth embodiment is the same as that in FIG. The transmission data signal is transmitted as in the second embodiment. Fault diagnostic signal generator 45
Then, the same signal as the data signal to be transmitted is generated as a failure diagnosis signal. However, a signal having a fixed relationship with the data signal to be transmitted may be created as the failure diagnosis signal, such as creating an inverted signal of the data signal. When the same signal as the data signal to be transmitted is used as the failure diagnosis signal, it means that the transmitter is duplicated as a result. The number of failure diagnosis signals is the same as the number of data signals to be transmitted in this example. Therefore, both have the same number of addresses in the address part.

The failure diagnosing device 5 takes in both the transmitted data signal and the failure diagnosing signal, compares the corresponding bits, and if they match, determines normal, and if they do not match, determines failure. Items in this case are the same as those in the third embodiment. The transmission control unit 41 is not duplicated in this example. This is because the fourth embodiment is intended for the failure diagnosis of individual data, and it is assumed that the common part is diagnosed, for example, by the second embodiment. Because there is.

Although various embodiments have been described above, in these embodiments, the failure diagnosis device does not necessarily have to be an independent device. In a multiplex transmission system, a programmable controller or a microcomputer system is often connected to the transmission system. In such a case, the connected programmable controller or microcomputer system can be used as a failure diagnosis device.

Some multiplex transmission systems can directly transmit analog signals as well as digital signals. For example, Japanese Patent Application No. 63-63 previously proposed by the present inventor.
The -172627 can directly transmit analog signals. A system for transmitting such analog signals,
Alternatively, the present invention can be applied to a system in which analog signals and digital signals are mixed and transmitted.

[Brief description of drawings]

FIG. 1 shows a data transmission system according to the present invention.

FIG. 2 shows a configuration of a reception transmission unit.

FIG. 3 shows a configuration of a failure diagnosis device.

FIG. 4 shows a configuration of a transmission unit for transmission.

FIG. 5 shows an example of a format of a transmission frame.

FIG. 6 shows a procedure for returning a reply for confirmation of transmission.

FIG. 7 shows a configuration of conventional multiplex transmission.

FIG. 8 shows a clock signal sent from the control device.

[Explanation of symbols]

 1 Control Unit 2, 3, 4 Transmission Unit 5 Fault Diagnosis Device 6 Transmission Line

Claims (4)

[Claims] 1. In a multiplex transmission system in which a plurality of transmission units are connected to a common transmission line, a failure diagnosis device is connected to the common transmission line, and a transmission address space is an address of a data signal and an address of a failure diagnosis signal. The transmission unit transmits the failure diagnosis signal at the address of the failure diagnosis signal independent of the address of the data signal, and the failure diagnosis device receives the failure diagnosis signal, and performs the failure diagnosis by the signal. A failure diagnosis device characterized by performing. 2. A fault diagnostic device transmits a fault diagnostic test signal, a transmission unit receives the test signal, and transmits the signal or a signal having a fixed relationship with the signal as a fault diagnostic signal, The failure diagnosis apparatus according to claim 1, wherein the failure diagnosis apparatus receives the failure diagnosis signal and compares the received signal with the test signal to perform failure diagnosis. 3. When the transmission unit B receives the data signal received from the transmission unit A, the transmission unit B diagnoses the data signal transmitted from the transmission unit A or a signal having a certain relationship with the data signal as a fault diagnosis. 2. The failure diagnosis apparatus according to claim 1, wherein the failure diagnosis apparatus receives the data signal and the failure diagnosis signal and compares the two signals to perform failure diagnosis. 4. The transmission unit transmits, as a failure diagnosis signal, a signal which is the same as or has a constant relationship with the data signal transmitted by itself, and the failure diagnosis device receives the data signal and the failure diagnosis signal. The fault diagnosis apparatus according to claim 1, wherein the fault diagnosis is performed by comparing the two signals.