JPH08223198A - Method and system for information transmission - Google Patents

Abstract

PURPOSE: To provide a duplex system transmission system without the need of taking synchronization even when a backup processor is added by providing a system for which the identity of the reception order of messages received inside respective processors is guaranteed. CONSTITUTION: A loop transmission line 1 is a medium for transmitting data transmitted and received by the respective processors 110, 120, 130 and 140 through transmission controllers 11, 12, 13 and 14 connected to the present processors. A function for transmitting and receiving the messages among programs stored inside the respective processors is provided. The processors 110 and 140 form a duplex system, the processor 110 becomes a main system and operates as the one for on-line and the processor 140 becomes a subordinate system and operates as the one for backup. They become to be the same constitution so as to let the subordinate system perform the backup when the main system fails and the same program is asynchronously operated simultaneously. The messages sent from the respective processors are sent out to the loop transmission line and circulated. Since the judgement of the data by a functional code is performed through an NCP for the respective data, the duplex system is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for a plurality of information processing devices to transmit a message using a loop transmission line to which the respective devices are connected, and more particularly to an information processing device which performs a dual system operation. The present invention relates to a suitable information transmission method when a device is connected.

[0002]

2. Description of the Related Art An example of a conventional system is shown in FIG.
The configuration shown in FIG. 4 can also be used in the present invention).

The system shown in FIG. 4 has a configuration in which a plurality of transmission control devices (NCP) are connected to one loop transmission line 1 and a processing device is connected to each transmission connection device.

Using such a system, necessary information such as messages has been transmitted between the processing devices.

Specifically, a plurality of programs are stored in each processing device, and a specific program among them is used to send a message. When sending a message, a function code indicating the contents of the message (destination processing device name, data contents, etc.) is added and the message is sent on the loop transmission line.

By the way, when the destination for sending a message using the specific program is another program (reception side program) in the same processing apparatus, the message is passed to the reception side program as it is, and further,
A message is sent to the loop transmission line via the transmission control device. Then, each transmission control device refers to the content of the function code added to the message transmitted on the loop transmission line, performs a process of fetching a necessary message, and the fetched message is sent to the processing device.

Further, a method has been used in which, after a message has been circulated on the loop transmission line, when the sent message returns to the transmission control device again, the message is discarded from the loop transmission line.

According to this method, the processing device on the message sending side can send the message to the loop transmission line without being aware of the existence of the processing device on the receiving side that needs the message. it can. in this way,
JP-A-56-4 discloses a method of circulating a message on a loop transmission line and discarding the message when it returns to the own transmission control device that has sent the message.
It is disclosed in Japanese Patent No. 0344.

A program for detecting an abnormal state of the processing device and the transmission control device in each processing device,
By a so-called survival monitoring program, a survival report message, which is a message for detecting an abnormal state, is sent in a predetermined cycle, and when the survival report message does not return within a predetermined time, the survival report message is returned. Has also been proposed in which it is determined that the processing device or the transmission control device, which should be sent, is in an abnormal state where the processing device or the transmission control device is not functioning normally (hereinafter appropriately referred to as “death”). By using such a method, it is possible to determine that the other processing device or the other transmission control device is in the "dead" state, and all the response information from the other processing device or the other transmission control device, If the survival report message does not arrive within the predetermined time, it can be determined that the transmission control device connected to the own processing device is in the “dead” state.

[0010]

In the above-mentioned prior art, the message is returned to the own transmission control device that has sent a message by making a loop on the loop transmission line disclosed in Japanese Patent Laid-Open No. 56-40344. When a message is sent using a program stored in a processing device, another program stored in the processing device will send the message. When necessary, the message is directly passed, and further, the message is sent out on the loop transmission line via the transmission control device. Therefore, the message transmission within the same processing device and the message transmission on the loop transmission line are performed. Was done asynchronously.

To this end, one online processing device connected to the loop transmission line and storing a plurality of programs stores a backup processing device (the same program is stored to have the same configuration as the online processing device). Then 2
In the case where both processing devices are operated asynchronously, the processing order of the messages to be received by each processing device must be the same, but the processing devices do not necessarily have to be installed in each processing device. The order in which the captured messages are captured is not guaranteed to be the same, and the processing sequence for messages differs between the online processing device and the backup processing device, and the backup processing device does not have a normal backup function. There was a problem that it would end up.

This is because, for example, in the processing in the same program stored in the online processing device and the backup processing device, the message A transmitted on the loop transmission line and the message A stored in each processing device are stored. When message A and message B are generated at the same time when message B transmitted within the same processing device sent by another program is required, the certain program in the online processing device causes message A, message It is conceivable that a message may be fetched in the order of B, while the certain program in the backup processing device may fetch the message in the order of message B and message A.

Particularly, when the performance of the online processing device and the backup processing device are different, the operation of each processing device is more likely to be different.
Therefore, even if the online processing device actually fails and the backup processing device activates the backup function, the various processes that have been performed before the startup will differ, and a normal backup function will be realized. I can't.

Further, in the above-mentioned prior art, the message is sent from a certain transmission control device, then goes around on the loop transmission line, and is discarded when returning to the transmission control device, so the message is sent. It does not return to the processor. For this reason, the survival monitoring program, which is a program for checking the abnormal state of the processing device and the transmission control device, in each processing device, sends a survival report message at a predetermined cycle, and When a report message does not arrive, in the method of determining that the processing device or transmission control device to which the survival report message should be sent is in the "dead" state, another processing device or other transmission control device is "dead". The purpose is to judge that it is in the state of.

In the online processor equipped with the backup processor, it is judged whether or not the transmission control device connected to the online processor is in the "dead" state,
Although it is necessary to set the operation mode of the processing device to other than online (that is, to activate the backup function), in order to determine that the transmission control device connected to its own processing device is in the "dead" state, A method of determining that the transmission control device connected to the own processing device is in the "dead" state when all the survival report messages from the other processing device or the other transmission control device do not arrive within the predetermined time Since it adopts, it is a process to judge "death" of its own processing device,
The survival monitoring process was complicated. Furthermore, in order to determine that the transmission control device connected to the self-processing device is in the "dead" state, the transmission control device or the processing device connected to the loop transmission line can be appropriately added or removed by adding or removing work. There is also a troublesome problem that the processing contents of the survival monitoring processing must be changed in consideration of the system configuration.

Therefore, an object of the present invention is that each transmission control device can carry out message transmission without knowing the address of the receiving side device, and a plurality of processing devices can be provided to each of the pair of processing devices constituting the duplex system. Is to provide information transmission means that guarantees the identity of the message reception sequence even when these programs are stored and activated, and the transmission control is connected to the loop transmission line. Even if the configuration of the device or the processing device is changed, it is possible to easily perform the survival monitoring process for determining that the transmission control device connected to the own processing device is "dead", and it is unnecessary to change the processing content. It is to provide a transmission means.

[0017]

In order to solve the above problems, the following means are considered.

That is, an information transmission method in which a plurality of information processing devices transmit a message by using a loop transmission line to which the respective devices are connected, and in the same information processing device, from a transmission unit to a reception unit. When passing a message, the message addressed to the own device is sent out on the loop transmission line, the sent message is looped over the loop transmission line and transmitted, and the transmitted message addressed to the own device is taken into the receiving unit and after being taken in. This is an information transmission method that discards the message on the loop transmission line.

Further, the following modes are also possible.

That is, there is provided an information transmission method for transmitting a message by using a loop transmission line in which at least one set of information processing devices for performing a dual operation is connected.
The message sent from the information processing device of one system performing the dual system operation to the loop transmission path is looped through the loop transmission path, and is captured by the information processing devices of both systems performing the dual system operation. This is an information transmission method of discarding the message on the transmission path.

[0021]

[Operation] The operation will be described below.

Assume an information transmission method in which a plurality of information processing devices transmit a message using a loop transmission line to which each device is connected.

First, when passing a message from the transmitting unit to the receiving unit in the same information processing apparatus, the message addressed to the own apparatus is sent out on the loop transmission line.

Then, the sent message is looped on the loop transmission line and transmitted, and the transmitted message addressed to the own device is taken into the receiving unit. Further, after the message is captured, the process of discarding the message on the loop transmission line is performed.

The operation of the other embodiment is as follows.

Assume an information transmission method for transmitting a message by using a loop transmission line in which at least one set of information processing devices performing a dual system operation are connected.

Then, a message is sent out on the loop transmission line from the information processing device of one of the systems which performs the dual system operation. Next, the sent message is looped on the loop transmission path.

Further, the information processing devices of both systems which perform the dual system operation fetch the message.

After fetching the message, the message on the loop transmission line is discarded.

As a result of the above operation, even if the online processing device is provided with the backup processing device and operated asynchronously, all the messages are fetched in both processing devices in the same order. It is possible to guarantee the same processing order of messages used by a plurality of programs stored in both processing devices, and it is guaranteed that the same operation is performed. Of course, even if the online processing device and the backup processing device have different performances, the same operation is guaranteed.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a configuration diagram showing a configuration example of a system for carrying out the present invention.

The loop transmission line 1 has a transmission control device 11,
12, 13, 14 (Network Communication Processor;
(Hereinafter, referred to as NCP), and each processing device 11 is connected to each transmission control device 11, 12, 13, 14.
0, 120, 130, 140 are connected.

The loop transmission line 1 includes data transmitted by each processing device via the NCP connected to the own device, and
Each processing device is a transmission medium for transmitting data received via the NCP connected to the processing device, and can be realized by, for example, an optical fiber cable, an electric cable, or the like.

Each processing device includes a storage area for storing a plurality of types of programs for performing a predetermined process, a storage means having at least a storage area for storing processing results of the programs, and a CPU for executing the programs.
It is configured to have at least.

Note that it also has a function of transmitting and receiving messages between programs stored in the processing device.

The processing device 110 and the processing device 140 constitute a so-called dual system, and the processing device 110 functions as a main system and the processing device 140 functions as a slave system.
Therefore, the processing device 110 becomes the online processing device, and the processing device 140 becomes the backup processing device.

When the master system is in an abnormal state such as a failure, the slave system continues to execute the processing that was being executed by the master system. In order to realize such a dual system configuration, the processing device 110 and the processing device 140 have the same configuration, and the same program is executed at the same time. As will be described later, according to the present invention, the processes of the processing device 110 and the processing device 140 are
It is not necessary to synchronize the operations, and asynchronous operations are possible.

Further, each NCP connected to the loop transmission line 1
Have the same configuration. Each NCP takes in only the necessary messages transmitted on the loop transmission line 1,
It has the function of sending to the corresponding processing device. Here, each NCP determines whether or not a message is necessary by referring to the function code added to the message data described later. Generally, it is sent to the processing device connected to its own NCP. Take in the received message as necessary data,
Send to the corresponding processing device.

The message sent from the processor is
It is sent out on the loop transmission line 1 via the corresponding NCP and transmitted on the loop transmission line 1. Where each NCP is
The recipient address is not set in the message so that the message can be transmitted without knowing the system configuration or the value of the address of the processing device on the receiving side.

Further, the data transmitted on the loop transmission line 1 is transmitted only to the corresponding processing device via NCP.

The message receiving process using the system shown in FIG. 2 will be described later in detail with reference to the flowchart.

Next, FIG. 3 shows an example of the data format of a message transmitted on the loop transmission line 1 which constitutes this system.

In each field, "FC" is a function code and is a code corresponding to the content of data. For example, it is 8-bit data that represents numbers from "1" to "256".

Then, each NCP refers to the function code and determines whether or not the data is required data. Therefore, each NCP stores at least one type of predetermined data in advance, and if the data matches the function code, the data (message or the like) having the function code is determined to be necessary data. To do.

Next, "SA" creates a message,
It is the address (source address) of the NCP that made the call,
An address is set in advance for each NCP. "C
“C” is a serial number required for transmission, and is, for example, a value added to the message from the initial value No. 1 in the order of transmission on the loop transmission line 1. “Data” is information to be processed by the program.

"FCS" is error detection data, and "F" is a flag indicating the beginning and end of the message.

Each NCP has fields "F, FC, S".
A, FCS "is used to control the information transmission,
Does not refer to. Each NCP compares the function code registered in advance with the processing device from the connected processing device with the “FC field” of the message on the loop transmission line 1, so that the processing device concerned can send the message. It is determined whether or not it is necessary, and only when it is necessary, the message on the loop transmission line 1 is fetched.

Each processing device generates the data contents when the data is generated by executing the program,
And the predetermined function code is D
The data is set in the data field and the FC field and sent to the NCP connected to the own device.

Then, each NCP formats the message received from the corresponding processing device so as to have the format shown in FIG. 3, and sends the message to the loop transmission line 1 by itself as the source.

Further, each NCP, when the message sent by itself as the originator returns after making a loop through the loop transmission line 1, when the corresponding processing device determines that the message is necessary, After sending the message to the corresponding processing device,
A so-called discard process of deleting the message from the loop transmission line 1 is performed. Temporarily, within a predetermined time set in advance,
If the message sent out on the loop transmission line 1 does not return, the message may be retransmitted a predetermined number of times until it returns. Such NCP information transmission control processing is exactly the same for each NCP.

Next, FIG. 1 shows a flowchart showing an embodiment of the processing performed by each NCP.

When a message is received, it is first judged whether the message is a message transmitted from the connected processing device or a message transmitted from the loop transmission line side, that is, the message. The direction of reception is determined (step 101).

Such a determination should be made by grasping whether the message is sent from the data bus connected to the corresponding processing device or the data bus connected to the loop transmission line. Can be judged by.

Then, if the message is sent from the connected processing device, the message format is generated so as to have the format described in FIG. 3 (step 107), and the message itself is the sender, and the loop transmission is performed. A message is sent out on the road and the process ends (step 108).

On the other hand, if the message is sent from the loop transmission line side, whether the message is needed by the corresponding (connected) processing device (simply referred to as "connection processing device") is determined. , FC is shown in FIG. 3 for determination (step 102). If the message is required, the message is transferred to the corresponding processing device (step 103).

Further, the NCP of the sender of the message
However, whether it is the own NCP or another NCP is determined by referring to the SA described in FIG. 3 (step 104).
If the source NCP of the message is the own NCP, the message is taken into the processing device, and then the message on the loop transmission line is discarded (step 105), while the source NCP of the message is the other NCP. If so, the message is directly transferred to the loop transmission line without any processing so as to be transmitted on the loop transmission line, and the process is terminated (step 106).

The above NCP processing does not discard the message as it is, even if the message source is the own NCP, and if the connected processing device needs the message, This indicates that the message is discarded after the message is transmitted to the connected processing device.

In order to perform the dual system operation, it is necessary that the data transmitted from the master system to its own NCP is also transmitted to the slave system. Therefore, when the slave NCP receives a message having a predetermined predetermined FC, the slave processing device may perform processing for determining that the message is necessary. . At this time, it will be described later with reference to the drawings that normal double system operation is guaranteed even if the processing devices constituting the dual system are operated asynchronously.

Next, the flow of messages in the system shown in FIG. 2 will be described with reference to FIG.

The processing devices 110 and 140 store the programs 300 and 301 and the programs 400 and 401, respectively. When the program 300 is executed, a message 200 is generated, and the message 200 is generated. Shall be received and used.

In this case, first, the processor 110 sends the message 200 generated by the program 300 to the NC.
Send to P11. The NCP 11 receives the message 200 from the connected processing device 110 and sends the message to the loop transmission line 1. The message 200 transmitted on the loop transmission line 1 is transmitted via the NCPs 12 and 13 to N
Reach CP14.

The NCP 14 is connected to the processing unit 140.
However, since the message 200 is required, the message 200 is fetched, the fetched message is transmitted to the processing device 140, and the message 200 is transferred to the loop transmission line 1.

Then, the processing unit 140 sends the message 2
Message 401 to program 401 that requires 00
And the program 401 executes the process using the message 200.

Further, the message 200 transmitted on the loop transmission line 1 reaches the NCP 11. NCP11 is
Since the connected processing device 110 needs the message 200, the processing device 110 captures the message 200 and sends it to the processing device 110.
Therefore, the message 200 is discarded. Then, the processing device 110 passes the message 200 to the program 301 that requires the message 200, and the program 301 executes the process using the message 200.

Further, referring to FIG. 5, the data flow in the case where the backup processing device is provided for the online processing device will be described in order. In this example, the backup processing device 140 has a backup function with respect to the online processing device 110, and the online processing device 110 is the main system and the backup processing device 1
It is assumed that 40 serves as a subordinate system and is performing a dual system operation.

Therefore, the program configurations in the processors 110 and 140 are the same, and here the program 30 is used.
0 and 301 and programs 400 and 401 have the same contents.

FIG. 5A is a diagram showing a flow of the message 201 when the program 400 and the program 300 receive the message 201 transmitted on the loop transmission line 1 from, for example, a processor (not shown). And the message 201 transmitted on the loop transmission line 1 is
NCP14 and NCP11 take in each, NC
P14 and NCP11 are respectively corresponding processing devices 1
A message 201 is sent to 40 and 110, and the processing devices 140 and 110 respectively execute the program 40 in their own device.
0, the message 201 is passed to the program 300, and the program 400 and the program 300 execute processing using the passed message 201, respectively.

Next, the program 400 and the program 30
0 sends a message 203 necessary for a program 401 and a program 301 existing in the same processing apparatus, respectively, and a message 202 sent from a processing apparatus (not shown) on the loop transmission line 1 401, when the program 301 receives,
The message flow will be described with reference to FIG.

It is assumed that the program 400 and the program 300 that have received the message 201 shown in FIG. 5A and executed the process using the message 201 next perform the process of sending the messages 204 and 203, respectively. . Here, since the double system operation is performed, the messages 204 and 203 have the same content.
The backup processing device 140 does not send the message 204 to the NCP 14 in order to prevent the same message from being sent to the loop transmission line 1. In order to prevent such a transmission, when the processing device of the master system is operating normally, the slave system may perform a process for blocking such a transmission. It should be noted that whether or not the main system processing device is operating normally may be determined by a known technique at predetermined time intervals or the like.

Then, the processor 110 sends the message 2
03 is sent to the NCP 11. The NCP 11 takes in the message 203 sent from the processing device 110 and sends it to the loop transmission line 1. And message 203
Transmits on the loop transmission line 1.

On the other hand, at substantially the same time, the message 202 transmitted on the loop transmission line 1 is NCP14, NCP11.
Respectively, NCP14, NCP11,
The message 202 is transmitted to the corresponding processing devices 140 and 110, respectively, and the processing devices 140 and 110 are processed.
Passes the message 202 to the program 401 and the program 301, respectively, and the program 401 and the program 301 respectively execute the process using the message 202.

Next, refer to FIG. 5C for the data flow when the program 401 and the program 301 receive the message 203 transmitted on the loop transmission line 1 generated in FIG. 5B. And explain.

Message 2 transmitted on loop transmission line 1
03 is loaded into the NCP14 and NCP11, respectively, and the NCP14 and NCP11 are loaded into the processing device 14 respectively.
0, the message 203 is transmitted to the processing device 110, and the processing device 140 and the processing device 110 pass the message 203 to the program 401 and the program 301, respectively.
The program 401 and the program 301 each execute a process using the message 203.

As described above, in the processing according to the present invention,
Message 20 sent by programs 400 and 300
4 and 203 are not directly passed to the programs 401 and 301 in the respective processing devices 140 and 110, but are temporarily transmitted to the loop transmission line 1 by sending a message to the loop transmission line 1. A method of passing the message once to the programs 401 and 301 is adopted.

According to such a method, the message 20
3, the message 202, the processing device 140 and the processing device 1
In 10, the processings are taken in and processed in the same order, so that the operations of the processing device 140 and the processing device 110 are not asynchronous even if no special synchronization means is provided, that is, the program 401 and 301 are respectively “message 202 → message 203”,
It is guaranteed that the processing using the received message is executed while maintaining the same order.

It is assumed that the messages 204 and 203 sent by the execution of the programs 400 and 300 are directly transmitted to the programs 401 and 301 in the processing units 140 and 110.
According to the conventional method of passing the message to the client, the message 203 (or the message 204) and the message 202 may be out of order. That is, the program 401 in the processing device 140 uses the messages 202, 204 (20
While the process using the message is executed in the order of 3), the program 301 in the processing device 110 may execute the process using the message in the order of the messages 203 and 202. If such a situation occurs, the function of the dual system operation will not be normally exhibited.

As described above, according to the present invention, in a transmission system configured with a loop transmission line, a special N
Even if a backup processing device is provided for an online processing device without providing a CP and all NCPs do not recognize the address of the receiving NCP, the order of messages received by both processing devices The identity of can be retained.

Therefore, it is possible to guarantee that the online processing device and the backup processing device operate in a synchronized state without providing any special means for synchronization. Even if the performances of the online processing device and the backup processing device are different, the present invention is effective because the same processing order is guaranteed in both processing devices.

In FIG. 6, a message generated from a processing device according to another embodiment of the present invention normally makes a round of a loop and returns to the processing device. The explanatory view of the method of judging the "death (not functioning normally, meaning an abnormal state)" of the NCP connected to is shown. In particular, the data flow is shown in detail.

For simplicity, the loop transmission line 1 has two NCs.
It is assumed that the P11 and P12 are connected, and that the processing apparatuses 110 and 120 are connected to the NCPs 11 and 12, respectively.

Note that each component basically has the same function as the component shown in FIG.

However, the processing device 110 is provided with an alive monitoring processing section 410, and an alive report sending program 411 is a program for sending an alive report message for checking an abnormality of a device (processing device, NCP, etc.), An alive report receiving program 412, which is a program for receiving the alive report message, and an alive monitoring program 413, which detects an abnormality of the device from the transmission / reception state of the alive report message, are stored.

Similarly, the processing device 120 is also provided with a survival monitoring processing section 510, and stores a survival report sending program 511, a survival report receiving program 512, and a survival monitoring program 513. Further, each processing device includes a resettable timer (not shown) for each of the NCPs included in the own processing device and other processing devices other than the own processing device. The timer expires when a predetermined time that has been set in advance has elapsed since the timer was reset, and information to that effect is notified to a predetermined program.

The survival report message may have a format similar to that shown in FIG. For example, the “Data” section may be configured to store predetermined specific data indicating that the message is a survival report message.

Here, the outline of the operation will be described.

First, the survival report sending program 511 in the processor 120 sends a survival report message 211. That is, the processing device 120 sends the message 211 to the NCP 12, and the NCP 12 sends the message 211 on the loop transmission line 1.

The NCP 11 sends the transmitted message 21
1 is received and transmitted to the processing device 110, and the message 2
11 is passed to the survival report reception program 412.

The survival report reception program 412 grasps the NCP that has transmitted the survival report message 211 with reference to the SA shown in FIG.
The CP timer is reset to the survival monitoring program 413.

On the other hand, the survival monitoring program 413 is activated by the time-up of the timer when the survival report message does not arrive within a predetermined time, and the NCP which issued the survival report message 211 or the NCP.
Understand that the processing device connected to is in an abnormal state, that is, in a dead state. The survival report message 212 sent by the survival report sending program 411 in the processing device 110 is also sent out on the loop transmission line 1 and completes a loop on the loop transmission line 1 to make the processing device 110 concerned.
And is passed to the survival report reception program 412. At this time, similarly, the survival monitoring program 413, if the survival report message does not arrive within a predetermined time,
It is activated when the corresponding timer times out, and the NCP connected to the self-processing device recognizes that it is in a dead state.

Next, FIG. 7 shows the processing relating to the survival report and monitoring.
This will be described with reference to the flowchart shown in FIG.

FIG. 7A is a flow chart showing a survival report sending program, which sends out a survival report message from itself at a predetermined fixed time interval (fixed cycle).
The process ends (step 111).

FIG. 7B is a flow chart showing the live report receiving program. Referring to "SA" (see FIG. 3) which is the data constituting the live report message, the timer corresponding to the NCP of the transmission source is shown. The timer is canceled to stop the time measurement (step 121), and the timer is set so that the time measurement of the timer is performed again, and the process is ended (step 12).
2).

FIG. 7C is a flow chart showing the survival monitoring program. First, the cause of timeout is judged (step 131). That is, it is determined to which device the timed-out timer is. Here, the timeout means that the life report message is not sent even after a predetermined time has elapsed.

If the timed-out timer is a timer for another device, the NCP corresponding to the timer
Alternatively, the processing device connected to the NCP recognizes that it is in a dead state and ends the processing (step 13).
3).

If the timer that has timed out is the timer for the own device, the NCP connected to the own processing device recognizes that it is in a dead state and ends the process (step 132).

By carrying out such a processing, it is possible to recognize that the other device or its own device is in a dead state, and when the online processing device is provided with the backup processing device, This is an effective method for monitoring the survival of both devices and the own device. In particular, since the NCP connected to the online processing device is in a dead state and performs a dual system operation, after the backup processing device shifts from the slave device to the master device in order to exert the online function, When the NCP recovers from the dead state and shifts to the normal ("live") state, there are two online processing devices connected to one loop transmission line. In order to avoid such a situation, whether each device is in a dead state,
It is effective to use the above method to perform a determination process at predetermined time intervals.

As described above, according to the present invention,
Since the reception order of the messages received in each processing device is guaranteed to be the same, even if a backup processing device is provided for the online processing device to operate, the means for synchronizing both devices is not provided. Normal double system operation can be guaranteed. Furthermore, even if only the online processing device is initially present and the backup processing device is added later, the additional work can be performed without changing the configuration of the online processing device.

Further, it is possible to detect not only whether or not another device is in an abnormal state, but also the abnormal state of the NCP connected to the own processing device by the simple existence monitoring process.

[0100]

According to the present invention, since the reception order of messages received in each processing device is guaranteed to be the same,
For example, even if a backup processing device is provided for the online processing device and the device is operated, normal dual system operation can be guaranteed without providing a means for synchronizing both devices.

Further, the simple existence monitoring process makes it possible to detect not only whether or not another device is in an abnormal state, but also an abnormal state of the NCP connected to the own processing device.

[Brief description of drawings]

FIG. 1 is a flowchart showing a process according to the present invention.

FIG. 2 is a configuration diagram showing a configuration example of a loop system.

FIG. 3 is an explanatory diagram of a format of a transmitted message.

FIG. 4 is an explanatory diagram showing a flow of a message transmitted in a loop.

FIG. 5 is an explanatory diagram showing a flow of a message transmitted in a system including a backup processing device.

FIG. 6 is an explanatory diagram showing a flow of a message for performing processing for existence monitoring.

FIG. 7 is a flowchart showing survival monitoring processing according to the present invention.

[Explanation of symbols]

1 ... Loop transmission line, 110 ... Processing device, 120 ... Processing device, 130 ... Processing device, 140 ... Processing device, 11 ... Transmission control device (NCP), 12 ... Transmission control device (NCP),
13 ... Transmission control device (NCP), 14 ... Transmission control device (NCP), 200 ... Message, 201 ... Message, 203 ... Message, 204 ... Message, 211
… Alive report message, 212… Alive report message,
300 ... Program, 301 ... Program, 400 ... Program, 401 ... Program, 411 ... Survival report sending program, 511 ... Survival report sending program, 412
... Alive report receiving program, 512 ... Alive report receiving program, 413 ... Alive monitoring program, 513 ... Alive monitoring program

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jira Kumayama 5-2-1 Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd. Omika factory

Claims (5)

[Claims] 1. An information transmission method in which a plurality of information processing devices transmit a message by using a loop transmission line to which the respective devices are connected, and from the transmission unit to the reception unit in the same information processing device. When passing a message, the message addressed to the own device is sent out on the loop transmission line, the sent message is looped over the loop transmission line and transmitted, and the transmitted message addressed to the own device is taken into the receiving unit and after being taken in. An information transmission method characterized by discarding the message on the loop transmission line. 2. An information transmission method for transmitting a message by using a loop transmission line in which at least one set of information processing devices for performing a dual system operation is connected, wherein one system for performing the dual system operation is provided. A message sent from the information processing device to the loop transmission line is circulated in the loop transmission line so that the information processing devices of both systems performing the dual system operation can capture the message and discard the message on the loop transmission line after the capture. An information transmission method characterized by: 3. The method according to claim 1, wherein when a message is transmitted / received between two programs existing in the information processing device, the message addressed to the device itself is transmitted from the program on the message transmitting side, which is the transmitting unit, An information transmitting method, characterized in that the program on the message receiving side which is the receiving unit receives the program. 4. The device according to claim 1, further comprising: when it is determined that the message addressed to the device itself sent on the loop transmission line is not sent to the device within a predetermined time, the device is in an abnormal state. An information transmission method characterized by determining that there is. 5. An information transmission system having a loop transmission line to which at least one set of information processing devices performing a dual system operation is connected, wherein each information processing device performing the dual system operation has a message on a loop transmission line. Means for sending the sent message, a means for causing the sent message to go around the loop transmission path and being acquired by both of the one set of information processing devices including the self information processing device, and a predetermined process using the acquired message. An information transmission system, comprising: