JPH07105829B2 - Communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention relates to a communication device for detecting a failure occurring in a system and preventing generation of bad data in the system due to the failure.

(Prior Art) In a communication system composed of a group of communication subjects connected by a communication path, the communication subject sometimes reads a message, and as a result, the contents processed based on the missing information are transmitted to other communication subjects. And the output is incorrect as a whole.

Therefore, it is necessary to constantly monitor the processing on each communication entity, stop the operation of the corresponding communication entity as soon as a failure or error is detected, and prevent the adverse effects of the failure or error from spreading to other communication entities.

However, although each communication entity checks the operation of the communication entity itself and performs appropriate processing when an error or failure occurs, the range that can be checked by the communication entity itself is limited.

Therefore, conventionally, an error or a failure is detected by multiplexing communication subjects that execute the same processing.
For example, if two communication subjects that perform the same process are prepared, and another communication subject receives the same message from these two communication subjects, it judges that it is correct and continues the process, but If the content of the message received from the subject is different, it is judged that an error or failure has occurred,
Perform corresponding processing.

(Problems to be Solved by the Invention) However, the above-mentioned method has the following problems.

The number of constituent elements of the system increases in order to multiplex the communication subjects, and their management becomes complicated.

Since the processing after receiving the message cannot proceed until the messages from all the communication entities in which the individual communication entities are multiplexed arrive, the processing speed of the entire system decreases. This problem becomes particularly serious when one of the multiplexed communication parties fails and does not send a message.

The present invention has been made based on such a situation, and communication capable of preventing abnormality detection of a communication subject and transmission of the abnormality to other communication subjects due to message skipping of the communication subject without multiplexing the communication subjects. The purpose is to provide a device.

[Configuration of the Invention] (Means for Solving the Problems) The present invention according to claim 1 has a communication path through which a message passes, a message sending function to this communication path, and a message reading function from the communication path. In a communication system including a plurality of communication entities, each of the communication entities counts and stores a cumulative amount of messages sent by all communication entities in the communication system, and the stored cumulative message amount. A third means for adding the message to be sent to the communication path by the communication entity itself, and a third means for comparing the cumulative message amount stored by the communication entity itself with the cumulative message amount added to the received message. Means and fourth means for detecting abnormality of the communication subject in the communication system based on this comparison.

According to a second aspect of the present invention, in the communication device according to the first aspect, the fourth means for detecting an abnormality of the communication subject in the communication system based on the comparison is such that the communication subject receives a message from another communication subject. In this case, when the cumulative message amount stored by the communication subject itself does not match the cumulative message amount added to the received message, the received message is invalidated.

The present invention according to claim 3 is a communication system comprising a communication path through which a message passes, and a plurality of communication subjects having a function of sending a message to the communication path and a function of reading a message from the communication path. A first means for the main body to count and store the cumulative amount of messages sent by all the communication parties in the communication system, and the stored cumulative message amount as a message to be sent to the communication path by the communication party itself. The second means for adding, the third means for comparing the cumulative message amount stored by the communication subject itself with the cumulative message amount added to the received message, and the result of this comparison, when they do not match And a fourth means for sending a message indicating that the communication subject that sent the message is abnormal to the communication path.

The present invention according to claim 4 is a communication apparatus comprising a communication path through which a message passes, and a plurality of communication subjects having a message sending function to the communication path and a message reading function from the communication path. A first means for the main body to count and store the cumulative amount of messages sent by all the communication parties in the communication system, and the stored cumulative message amount as a message to be sent to the communication path by the communication party itself. The second means for adding, the third means for comparing the cumulative message amount stored by the communication entity itself with the cumulative message amount added to the received message, and the result of this comparison, when the two do not match A fourth means for sending the message to the communication channel, and a message indicating that the communication entity itself is abnormal from another communication entity within a dynamically or statically determined period. When it received or the number determined the over-di static or dynamic, and a fifth means for stopping the communication function of the communication partner itself.

According to a fifth aspect of the present invention, in the communication device according to the third aspect, the communication subject adds an abnormal identifier to a message to be sent, and the cumulative message added to the message received from the other communication subject by the communication subject. When the amount does not match the cumulative message amount stored by the communication subject itself,
Abnormal identifier of the message and means for transmitting a message indicating that the communication subject that sent the message is abnormal to the communication path, and the same abnormal identifier of the message from the number of communication subjects that are statically or dynamically determined or more And a means for stopping the communication function of the communication subject itself when receiving a message indicating that the communication subject itself is abnormal.

(Operation) In the present invention, each communication entity counts and stores the cumulative amount of messages sent by the communication entities in the communication system, and adds the cumulative message amount to the message to be sent to the communication path by the communication entity itself. is doing. Then, the cumulative message amount stored by the communication subject itself is compared with the cumulative message amount added to the received message, and the abnormality of the communication subject in the communication system is detected based on the comparison result. It is possible to prevent the abnormality detection and abnormality of the communication subject from being transmitted to other communication subjects due to the message skipping of the communication subject without multiplexing the communication subjects performing the communication.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

FIG. 1 is a diagram showing a configuration of a communication device according to an embodiment of the present invention.

As shown in the figure, this device is configured by connecting a plurality of communication subjects 2a, 2b ... To the communication path 1.

Communication subject 2a, 2b ... (Hereinafter, these are collectively referred to as communication subject 2
And ) Is connected to the communication path 1 and main processing units 3a, 3b ... (Hereinafter collectively referred to as main processing unit 3) that execute processing unique to each communication main body 2, The communication processing units 4a, 4b ... (Hereinafter, which execute information exchange between the two
These are collectively referred to as the communication processing unit 4. ) And.
That is, the communication entity 2 sends a message to the communication channel 1 via the communication processing unit 4 and receives a message on the communication channel 1 to exchange information with another communication entity 2.

FIG. 2 is a diagram showing the configuration of the communication processing unit 4.

The communication processing unit 4 is composed of a transmission processing unit 5, a reception processing unit 6 and a comparison processing unit 7, as shown in FIG.

The transmission processing unit 5 receives the message sent by the main processing unit 3 through the line 8 and performs processing such as packet disassembly if necessary, but also performs the following processing in cooperation with the comparison processing unit 7.
That is, the transmission processing unit 5 receives, via the line 9 from the comparison processing unit 7, the accumulated message amount that is the accumulation of the message amounts that have passed through the communication path 1 and is stored in the comparison processing unit 7 up to the present time. Then, an amount obtained by adding the amount of the message to be transmitted by the processing unit 3 to the accumulated message amount is calculated, and the calculation result is set as the accumulated message amount after the message is transmitted by the transmission processing unit 5.

Next, as shown in FIG. 3, the transmission processing unit 5 defines the message to be transmitted as the message body, and the destination identifier of the message and the identifier of the communication subject 2 to which the transmission processing unit 5 as the sender of the message belongs. , A message having a format in which the amount of outgoing message and the previously calculated cumulative amount of message after outgoing message are added is created and sent to the communication path 1 through the line 11.

Further, when the transmission of the message ends normally, the transmission processing unit 5 notifies the comparison processing unit 7 through the line 10 of the previously calculated cumulative message amount after the message transmission.

Then, when the comparison processing unit 7 receives the cumulative message amount via the line 10, the comparison processing unit 7 replaces the cumulative message amount stored by the comparison processing unit 7 itself with the received cumulative message amount.

Here, as the cumulative message amount, it is possible to use the number of messages that have passed through the communication path 1, the cumulative message size, or the like. However, when the number of messages is used, the amount of outgoing message is always "1", and therefore the amount of outgoing message in the message format shown in FIG. 3 is unnecessary.

On the other hand, the message from communication channel 1
The reception processing unit 6 receives it.

The reception processing unit 6 checks the destination of the received message and, if it is for the communication subject 2 to which the reception processing unit 6 itself belongs, extracts the message body from the received message and performs packet assembly or the like if necessary. And track 13
To the main processing unit 3 through.

In addition to such processing, the reception processing unit 6 receives the received message from the received message regardless of whether the destination of the received message is the communication subject 2 to which the reception processing unit 6 itself belongs, that is, FIG. The sender, the outgoing message amount, and the cumulative message amount are extracted from the message shown in (1). Note that when the number of messages is used as the message amount, the outgoing message amount need not be extracted. Then, these extracted messages are notified to the comparison processing unit 7 through the line 14.

When the comparison processing unit 7 receives the sender, the outgoing message amount, and the cumulative message amount via the line 14, the comparison processing unit 7 itself adds the received message amount to the cumulative message amount stored by the comparison processing unit 7 and the received cumulative value. Compare with message volume. If they do not match, it is determined that the communication subject 2 corresponding to the received transmission source has failed, and if necessary, the main processing unit 2 is notified via the line 15. on the other hand,
When they match, the cumulative message amount stored in the comparison processing unit 7 itself is replaced with a value obtained by adding the received message amount to the cumulative message amount stored in the comparison processing unit 7 itself. However, the same effect can be obtained even if the final replacement process is performed regardless of the comparison result.

However, in a communication path such as a LAN, only one communication entity 2 can send a message at the same time, so a group of communication entities that normally perform message transmission on the communication path 1 and message reception from the communication path 1 The cumulative message amount stored in the comparison processing unit 7 belonging to is always the same.

Therefore, when the comparison processing unit 7 finds a mismatch between the cumulative message amount stored in the comparison processing unit 7 itself and the received cumulative message amount in the above process, the communication subject 2 or the message to which the comparison processing unit 7 itself belongs It can be seen that the communication subject 2 that has sent

In the above description, when a mismatch is found, it is determined that the sender of the message has an abnormality, and the communication party on the receiving side continues to operate. Even if the communication party on the receiving side has a failure, when the communication party next sends a message, the comparison processing unit 7 of the receiving communication party 2 detects an abnormality on the side sending the message. Therefore, no inconvenience will occur.

The transmission processing unit 5 shown in FIG. 2 notifies the comparison processing unit 7 of the cumulative message amount after the message is sent via the line 10, but instead, the transmission processing unit 5 notifies the sending message amount and the comparison processing unit 7 sends the message. The cumulative message amount after transmission may be calculated. In the case of this method, if the number of messages is further used as the message amount, the transmitted message amount is always "1". Therefore, the transmission processing unit 5 normally transmits the message to the comparison processing unit 7 through the line 10. All you have to do is notify.

In the message shown in FIG. 3, the cumulative message amount calculated by the transmission processing unit 5 after sending the message is used as the cumulative message amount, but instead, the cumulative message amount before sending the message is used to receive the message. The side can also calculate the cumulative message amount after sending the message.

Further, the outgoing message amount shown in FIG. 3 may be any value as long as the outgoing message amount can be calculated by it. For example, when the cumulative message amount after sending the message is used as the cumulative message amount, before sending the message. If the cumulative message amount of is known, the outgoing message amount can be calculated.

Next, a second embodiment of the present invention will be described.

FIG. 4 is a diagram showing the configuration of the communication processing unit according to the second embodiment of the present invention.

That is, in the comparison processing unit 7 shown in FIG. 2, the comparison processing unit 7 compares the cumulative message amount stored in the comparison processing unit 7 itself with the cumulative message amount included in the received message to perform communication. Although the abnormality of the main body was discovered, the communication main body 2 in which the adverse effect of the abnormality is normally operating in the configuration of the second embodiment shown in FIG.
It further has the function of preventing the spread of

The transmission processing unit 16 shown in FIG. 4 operates in the same manner as the transmission processing unit 5 shown in FIG. 2 operates in conjunction with the comparison processing unit 7 in cooperation with the comparison processing unit 18.

On the other hand, in the reception processing unit 6 shown in FIG. 2, the message body of the received message is directly sent to the main processing unit 3 through the line 13, whereas in the embodiment shown in FIG.
The message body is also sent to the main processing unit 3 via the comparison processing unit 18. That is, when the reception processing unit 17 receives a message from the communication path 1 through the line 23, if the destination is the communication subject 2 to which the message belongs, the reception processing unit 17 performs processing such as packet assembling, if necessary, for the entire message, When the destination is not the communication entity 2 to which the reception processing unit 17 itself belongs, at least a portion including the transmission source, the transmission message amount, and the cumulative message amount of the message shown in FIG. 3 is transferred to the comparison processing unit 18 through the line 24. To do.

The comparison processing unit 18, which has received the signal through the line 24, compares the cumulative message amount stored by the comparison processing unit 18 itself with the value of the sent message received and the received cumulative message amount. If they are different, it is determined that the communication subject 2 corresponding to the received transmission source has an abnormality, and the message body is not sent to the main processing unit 3. If necessary, the processing unit 3 is notified of the abnormality of the communication subject 2 corresponding to the transmission source through the line 25. On the other hand, if the two values compared by the comparison processing unit 18 match, the cumulative message amount stored in the comparison processing unit 18 is replaced with the cumulative message amount received through the line 24, and the destination of the message is the comparison processing unit. If it is the communication entity 2 to which 18 itself belongs, the message body is sent to the main processing unit 3 through the line 25.

In this way, in this embodiment, by stopping the transfer of the message sent from the communication subject 2 that has detected the abnormality to the main processing unit 3, the communication subject 2 in which the abnormality is operating normally
It is possible to prevent the spread to.

Next, a third embodiment of the present invention will be described.

FIG. 5 is a diagram showing the configuration of the communication processing unit according to the third embodiment of the present invention.

That is, in the communication processing unit shown in FIG. 2 or 4,
When the comparison processing units 7 and 18 detect an abnormality, it is not possible to determine whether the abnormality has occurred in the communication subject 2 to which the comparison processing units 7 and 18 themselves belong or in the communication subject 2 that is the sender of the message. Although not possible, the communication processing unit shown in FIG. 5 has a device configuration in which the communication entity 2 in which an abnormality has occurred is identified and the communication activity by the identified communication entity 2 is stopped. With this configuration, it is possible to prevent unnecessary messages from continuously flowing to the communication path 1 from the communication subject 2 in which an abnormality has occurred.

The configuration of the communication processing unit shown in FIG. 5 is a modification of the configuration of the communication processing unit shown in FIG.

That is, the transmission processing unit 27, the reception processing unit 28, and the comparison processing unit 29 perform substantially the same operations as the transmission processing unit 16, the reception processing unit 17, and the comparison processing unit 18 shown in FIG. 4, respectively.

The transmission processing unit 27 and the reception processing unit 28 are different from those shown in FIG. 4 and indicate from the abnormality processing unit 30 that the communication subject 2 to which the communication processing unit itself belongs is abnormal through the lines 40 and 41, respectively. It is designed to receive a signal, and when it receives this signal, it stops transmitting and receiving operations.

Further, the comparison processing unit 29, unlike the one shown in FIG. 4, also sends a signal to the transmission processing unit 27 and the abnormality processing unit 30 through the lines 38 and 39. That is, the comparison processing unit 29, like the comparison processing unit 18 shown in FIG. 4, is included in the cumulative message amount stored in the communication processing unit itself and the message received from the reception processing unit 28 through the line 36. The cumulative message amounts are compared. If the two values do not match as a result, a message indicating that the message transmission source is abnormal is generated, and the transmission processing unit 27 and the communication path 1 are transmitted via the line 38.
Send to. If the message obtained through the line 36 indicates that the communication subject 2 to which the communication processing unit itself belongs is abnormal, the comparison processing unit 29 sends the message to the line.
The signal indicating the abnormality is not transmitted to the main processing unit 3 through 37, but is transmitted to the abnormality processing unit 30 through the line 39 together with the transmission source included in the message.

The abnormality processing unit 30 stores the signal obtained through the line 39 for a predetermined period, and a message indicating that the communication subject 2 is abnormal from a predetermined number of different communication subjects 2 within a certain period. When the communication subject 2 is received, it is determined that the communication subject 2 is abnormal, and an abnormality notification is sent to the transmission processing unit 27 and the reception processing unit 28 through the lines 40 and 41, respectively, and their operations are stopped.

Here, the number of communication subjects 2 that has sent a message indicating an abnormality necessary for determining that the communication subject 2 is abnormal is, for example, “2” or a majority of the number of communication subjects 2 that are operating in the system. And so on. Further, the valid period of the message indicating the abnormality received from the communication subject 2 can be set or measured as an absolute time defined by a timer or the like, or as the number of messages received by the reception processing unit 28 from the communication path 1.

As the message identifier, the message generation time shown in FIG. 6 can be used as a pair of the message generation time and the transmission source. However, when the comparison processing unit 29 transmits a signal indicating that the transmission source is abnormal through the line 38, the received message is received. If the message identifier of is added as the abnormality identifier, the abnormality processing unit 30 determines that the abnormality is detected when the abnormality processing unit 30 receives an abnormality notification that is detected and notified by a different number of communication subjects 2 having the same abnormality identifier. You can also do it.

In any case, according to the present embodiment, the communication main body 2 that has recognized that the plurality of communication main bodies 2 is abnormal in a short time period by such means is specified as abnormal, and therefore the abnormality identification accuracy is Get higher

[Advantages of the Invention] According to the present invention, it is possible to detect an abnormality of a communication subject due to a message skipping of the communication subject without multiplexing the communication subjects and to prevent the abnormality from being propagated to other communication subjects.

Therefore, the complication due to the multiplexing of the processing on each communication entity is eliminated, and further, it is possible to prevent the decrease in the processing speed due to the waiting when the messages arrive from all the multiplexed communication entities.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a communication system according to an embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a communication processing unit in FIG. 1, FIG. 3 is a diagram showing an example of its message, FIG. FIG. 4 is a diagram showing the configuration of a communication processing unit according to the second embodiment of the present invention, FIG. 5 is a diagram showing the configuration of the communication processing unit according to the third embodiment of the present invention, and FIG. It is a figure which shows the example of a message. 1 ... communication path, 2a, 2b ... communication subject, 3a, 3b ... main processing section, 4a, 4b ... communication processing section, 5 ... transmission processing section, 6 ...
Reception processing unit, 7 ... Comparison processing unit.

Continuation of the front page (56) References "OSI" Japanese Standards Association (1987) p. 56 Figure 2.13, P. 100 to 101 Figure 3.22 and Table 3.11

Claims (5)

[Claims] 1. A communication system comprising a communication path through which a message passes, and a plurality of communication entities having a function of sending a message to the communication path and a function of reading a message from the communication path, wherein each communication entity communicates with each other. A first means for counting and storing the cumulative amount of messages sent by all communication parties in the system; and a second means for adding the stored cumulative message quantity to a message to be sent to the communication path by the communication party itself. Means for comparing the cumulative message amount stored by the communication subject itself with the cumulative message amount added to the received message, and the abnormality of the communication subject in the communication system is detected based on this comparison. A communication device comprising: a fourth means. 2. A fourth means for detecting an abnormality of a communication subject in a communication system based on a comparison, when the communication subject receives a message from another communication subject, the cumulative information stored by the communication subject itself. 2. The communication device according to claim 1, wherein the received message is invalidated when the message amount does not match the cumulative message amount added to the received message. 3. A communication system comprising a communication path through which a message passes, and a plurality of communication entities having a function of sending a message to the communication path and a function of reading a message from the communication path, wherein each communication entity communicates with each other. A first means for counting and storing the cumulative amount of messages sent by all communication parties in the system; and a second means for adding the stored cumulative message quantity to a message to be sent to the communication path by the communication party itself. Means for comparing the cumulative message amount stored by the communication subject itself with the cumulative message amount added to the received message, and if the result of this comparison is that they do not match, the message is And a fourth means for transmitting a message indicating that the transmitted communication subject is abnormal to the communication path. 4. A communication device comprising a communication path through which a message passes, and a plurality of communication entities having a message sending function to the communication path and a message reading function from the communication path, wherein each communication entity communicates with each other. A first means for counting and storing the cumulative amount of messages sent by all communication parties in the system; and a second means for adding the stored cumulative message quantity to a message to be sent to the communication path by the communication party itself. Means for comparing the cumulative message amount stored by the communication subject itself with the cumulative message amount added to the received message, and if the result of this comparison is that they do not match, the message is A fourth means for sending out to the communication channel and a static message from another communication entity indicating that the communication entity itself is abnormal within a period determined dynamically or statically. Or a fifth means for stopping the communication function of the communication subject itself when more than the dynamically determined number is received. 5. A cumulative amount of messages added by a communication subject to a message sent from another communication subject by an abnormal identifier added to a message sent by the communication subject, and a cumulative message stored by the communication subject itself. A means for sending a message indicating that the abnormal identifier of the message and the communication subject that sent the message is abnormal to the communication path when the amounts do not match, and a number of communication subjects that are statically or dynamically determined 4. When receiving a message indicating that the communication subject itself is abnormal from the communication subject together with the same abnormality identifier of the message, the communication subject's own communication function is stopped. The communication device described.