JPH1079746A - Distribution controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a distribution controller in which a fault occurrence is recognized and a proper processing is conducted even when a usual station with a fault cannot transfer a fault flag to a management station. SOLUTION: A management station 1 sends a transmission frame 49 to confirm whether or not each station is normal to usual stations 2, 3, 4 at a prescribed interval and when the station 2 does not return any response, the station 1 sets '1' to a fault flag 45 of the frame 49 and sets '2' denoting the station 2 to a command 46 and transfers the command in a transmission frame 50 to the other stations 3, 4. The stations 3, 4 recognize a fault of the station 2 from the flag 45 and the command 46 of the frame 50 and disconnects the station 2 on the network. The management station 1 transfers a transmission frame 52 and installs a program used to stop the processing of the priority 3 executed by the station 4 and to execute the processing of the station 2 by using a transmission frame 53 and sets an execution flag 44 to a register 40. When the execution flag 44 is set, the usual station 4 sets a flag 41 to the register 40 and clears a fault flag 42, a processing assembly work flag 43 and a program execution flag 44 to execute the processing of the processing priority 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data transfer in which a header section and a data section are incorporated in a transmission frame and transferred to an external device (reception side), and a text section is restored on the reception side. The present invention relates to a distributed control device for data transfer between a plurality of normal stations.

[0002]

2. Description of the Related Art Conventionally, in a distributed switching system, a system processor for controlling the entire switching system is housed in a main unit set in a switching room. In this distributed switching system, a system in which each node has an exchange process for controlling the entire distributed switching system is disclosed in Japanese Patent Publication No. 7-08.
No. 7458 (control method of distributed switching system).

The control method of the above-mentioned distributed switching system is such that each node is provided with a switching process for controlling the entire distributed switching system, so that a main unit is not provided in the switching room. Even if the system is stopped, the node having the next priority has a redundant configuration in which the switching system of the entire distributed switching system is executed, thereby improving serviceability and reliability.

FIG. 11 shows the above-mentioned Japanese Patent Publication No. 7-08745.
FIG. 8 is a schematic block diagram of a control method of a distributed switching system described in Japanese Patent Application Publication No. 8 (JP-A-8) In FIG. 11, each node 101, 1
02, 103 and 104 are respectively the node processor 1
11, 121, 131, and 141, and system processors 112, 122, 132, and 142, all of which are connected via a common control bus 105.

[0005] The four system processors 112, 12
One of the system processors 2, 132, and 142 is performing switching processing of the distributed switching system, and the other system processors are in a standby state. Here, assuming that the system processor 112 has failed, the second-priority system processor 122 performs operation display and enters the operation state.

[0006]

However, the control method of the distributed switching system disclosed in Japanese Patent Publication No. 7-087458 has the following problems. Even a node that is unused during normal operation and used only during abnormal operation has a normal operation control function, but does not have an operation function during abnormal operation. For this reason, despite the large circuit scale, it has not been possible to execute an appropriate operation at the time of abnormality.

Therefore, among a plurality of communication stations, a certain communication station performs a distribution function having a low priority in a normal state, while supporting a distribution processing of another station in an abnormal state or when the load becomes large. It would be useful if switching to a function could be done by simply changing the program.

[0008] However, the above-mentioned Japanese Patent Publication No. 7-08745.
In the control method of the distributed switching system described in Japanese Patent Application Laid-Open No. 8 (1999) -2000, only the process of the same content is executed in the normal case and the abnormal case, and different processes cannot be executed in the normal case and the abnormal case. Was.

In the control method of the distributed switching system described in Japanese Patent Publication No. Hei 7-087458, when an abnormality or a failure occurs, the function can only be transferred to the next-priority distributed system for processing. Processing could not be performed.

Therefore, a distributed control device which can appropriately cope with an abnormality has been considered. FIG. 12 is a schematic block diagram of the configuration of the distributed control device, and shows a process of the distributed control when the normal station 2 is abnormal. This decentralized control device is
It is a bus-type or ring-type LAN that has a communication node composed of a plurality of normal stations 2, 3, and 4 and whose transmission is controlled.

In this distributed control apparatus, the normal stations 2, 3, and 4 have the processing priority of the normal station 2, the processing priority of 1, the normal station 3 the processing priority of 2, and the normal station 4 Has a processing priority of 3. Normal stations 2, 3, 4
As shown in FIG. 12B, each of them has a distributed control register 40 therein.

Normally, the stations 2, 3, and 4
A distribution control execution flag 41, an abnormality flag 42, and a processing division flag 43 of 0 can be set. The management station 1 can set the program execution flag 44 in the distribution control register 40.

First, consider the case where the normal station 2 has failed. The normal station 2 stores the abnormality flag 42 in the distributed control register 4
Set to 0. The management station 1 determines that the normal station 2
Is set in the distributed control register 40, the transmission frame 61 for stopping the processing of the processing priority 1 currently executed by the normal station 2 is transferred to the normal station 2.

The normal station 2 sends a transmission frame 6 from the management station 1.
When the station 1 is received, the normal station 2 stops the processing of the processing priority 1 currently executed. Thereafter, the management station 1 issues a request to the normal station 4 with the lowest processing priority 3 for the processing priority.
The transmission frame 62 for stopping the processing of the processing priority 3 performed by the normal station 4 is transferred. When the normal station 4 receives the transmission frame 62 from the management station 1, the normal station 4 stops the processing of the processing priority 3 currently executed by the normal station 4.

After that, the management station 1
A program for executing the processing of the processing priority 1 which has been executed by the normal station 2 is installed in the transmission frame 53. Thereafter, the management station 1 sets the program execution flag 44 in the distribution control register 40.

When the normal station 4 confirms that the program execution flag 44 has been set in the distribution control register 40, the normal station 4 sets the distribution control execution flag 41 in the distribution control register 40, and sets the abnormal state set in the distribution control register 40. Flag 4
2. The processing division flag 43 and the program execution flag 44 are cleared, and the processing of the processing priority 1 is executed.

As described above, the distribution control register 40 includes the distribution control execution flag 41, the abnormality flag 42, the processing division flag 43, and the program execution flag 44, and the transmission frame also includes the setting flag. Then, when the normal station is abnormal or when the load becomes heavy, it notifies the management station 1 by a transmission frame or a flag.

Further, the management station 1 transfers a transmission frame or flag received by the management station 1 to the normal station having a low-priority dispersing function, which indicates that the management station 1 has received an abnormality or that the load has become heavy. By installing a distributed processing program, the system is switched to the distributed processing to improve the reliability of the entire system.

However, the distributed control device capable of coping with the above-described abnormality also has the following problems. That is, when the normal station in which an abnormality occurs or the load becomes large cannot transfer the abnormality flag or the like to the management station, for example, when the power of the normal station in which the abnormality or the like occurs is turned off, or when the abnormality flag or the like is managed. If the control station cannot receive the data even if it is transferred to the station, for example, if the cable is disconnected, if the error flag is noise, or if the error flag is not transferred to the control station due to attenuation of the communication signal, an error may occur. However, there is a problem in that it is not possible to recognize the information and appropriate processing cannot be performed.

[0020] The object of the present invention is to provide a method in which a normal station in which an abnormality has occurred or a heavy load cannot transfer an abnormal flag or the like to a management station, or even if an abnormal flag or the like is transferred to the management station, the management station can perform the processing. An object of the present invention is to realize a distributed control device capable of recognizing occurrence of an abnormality and the like and performing appropriate processing even when reception is not possible.

[0021]

[Means for Solving the Problems]

(1) In order to achieve the above object, the present invention is configured as follows. In other words, it recognizes that the received data is valid data, and if it is not valid data, a plurality of normal stations for distributed control that notify the destination that the data is not valid, and a plurality of these normal stations. In a distributed control device having a management station that performs distributed and centralized control by transmitting and receiving data, each of the plurality of normal stations determines whether the centralized control is a distributed control, and displays the determined control content in a distributed control setting. And an abnormality display setting unit that determines whether the function of the normal station is normal or abnormal, and indicates whether the function is normal or abnormal,
A process sharing request display setting unit to determine whether or not to request the sharing of the processing performed by the normal station to another normal station, and a distributed control process of the plurality of normal stations. A priority determining unit for determining the priority of the processing of the normal station, wherein the management station determines whether there is no response to the data transfer to each of the normal stations, and an abnormal display setting unit of each of the normal stations. When an abnormality is set in the normal station, an abnormality determination unit is provided for determining that the normal station is abnormal.

The management station determines that the normal station is abnormal when there is no response to data transfer to each normal station and when an abnormality is set in the abnormality display setting section of each normal station. Is provided when an abnormality occurs in a normal station and an abnormal flag or the like cannot be transferred to the management station, or when an abnormal flag or the like is transferred to the management station but cannot be received by the management station. Also, it is possible to recognize the occurrence of an abnormality or the like, and the management station can perform appropriate processing.

(2) Preferably, in the above (1),
Each of the above normal stations and the management station respectively indicates a header portion indicating at least a transmission source and a transmission destination, a flag indicating normal or abnormal, and indicates which normal station indicates the normal or abnormal normal station. And a transmission processing unit that transmits a transmission frame including a data portion having a flag to another normal station or a management station.

The normal station having no abnormality can recognize in the transmission frame transmitted by the transmission processing section which normal station has the abnormality based on the indicated information, Can be executed.

(3) Preferably, in the above (2), the data portion of the transmission frame includes a flag indicating whether or not to request the sharing of another process to be performed to another normal station. The normal station requesting the sharing of the processing further has a flag indicating which normal station.

The normal station having no abnormality can recognize in the transmission frame transmitted by the transmission processing section which normal station has the abnormality based on the indicated information, and request the processing division of labor. The normal station that has not performed can recognize which normal station has requested processing sharing from the transmission frame transmitted by the transmission processing unit based on the indicated information, and perform appropriate processing for it. Becomes possible.

(4) A plurality of normal stations for distributed control for recognizing that the received data is valid data, and when not valid, notifying the transmission destination that the data is not valid. In a distributed control apparatus having a plurality of normal stations and a management station that performs distributed and centralized management control by transmitting and receiving data, each of the plurality of normal stations determines whether centralized control or distributed control, and the determined control content. , A determination control unit that determines whether the processing performed by the normal station is overloaded, and an overload display setting unit that determines whether the processing performed by the normal station is overloaded. A process sharing request display setting unit for determining whether or not to request sharing to a station, and a priority determination for determining the priority of the processing of the normal station among the distributed control processing of the plurality of normal stations; And the above, The physical station determines that the normal station is overloaded when there is no response to the data transfer to each of the normal stations and when the excess is set in the overload display setting section of each of the normal stations. An overload judging unit is provided.

The management station determines that the normal station is overloaded when there is no response to the data transfer to each of the normal stations and when an overload is set in the overload display setting section of each of the normal stations. Since the overload judging unit is provided, the overload occurs in the normal station and the overload flag or the like cannot be transferred to the management station, or even if the overload flag or the like is transferred to the management station, the management station cannot receive. Also, it is possible to recognize the occurrence of overload and the like, and appropriate processing by the management station becomes possible.

(5) Preferably, in the above (4),
Each of the normal stations and the management station respectively indicates a header portion indicating at least a transmission source and a transmission destination, a flag indicating whether or not it is overloaded, and indicates which of the normal stations the overloaded or not is indicated. And a transmission processing unit that transmits a transmission frame including a data portion having a flag to another normal station or a management station.

The normal station that has not generated an overload can recognize which normal station has overloaded on the basis of the indicated information in the transmission frame transmitted by the transmission processing section, Can be executed.

(6) Preferably, in the above (5), the data portion of the transmission frame includes a flag indicating whether to request the sharing of the processing being executed to another normal station, The normal station requesting the sharing of the processing further has a flag indicating which normal station.

The normal station that has not generated an overload can recognize which normal station has overloaded on the basis of the information shown in the transmission frame transmitted by the transmission processing section, and requests the division of processing. The normal station that has not performed can recognize which normal station has requested processing sharing from the transmission frame transmitted by the transmission processing unit based on the indicated information, and perform appropriate processing for it. Becomes possible.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a distributed control device according to a first embodiment of the present invention, and is an example in which a process performed when a normal station is abnormal can be appropriately executed.

The distributed control apparatus according to the first embodiment includes a bus-type or ring-type LAN, which is controlled for transmission and has a communication node composed of a management station 1 and four nodes of normal stations 2, 3, and 4. Has become.

As shown in FIG. 2, the management station 1
1, ROM 32, RAM 33, transmission controller 34
, An internal bus 35 for connecting them, and an external RO for storing a distributed processing program to be executed in the memory expansion normal station.
M36 and an external R that stores network variables for communication
The external ROM 36 and the R
It comprises a memory expansion bus 38 connecting the AM 37.

The CPU 31 controls the transmission controller 34 in accordance with the program stored in the ROM 32 to transmit and receive various frames to and from the transmission path 30.
The RAM 33 is used as a buffer memory for temporarily storing transmission / reception data and other various data. Further, the external ROM 36 stores a distributed processing program to be executed by the memory expansion normal station.

The external RAM 37 stores communication network variables. External ROM 36 and external RAM 37
When used in a normal station, if the capacity of a network variable for communication with a distributed processing program to be executed is small, a configuration similar to that used in the normal stations 2, 3, and 4 is also possible.

The CPU 31 of the management station 1 functions as a functional block when the normal stations 2, 3, and 4 do not respond to the data transfer to the normal stations 2, 3, and 4. An abnormality judging unit for judging the station as abnormal, a header part indicating at least the transmission source and the transmission destination, a flag indicating normal or abnormal, and indicating which normal station indicates the normal or abnormal normal station A data having a flag, a flag indicating whether or not to request sharing of the processing being executed to another normal station, and a flag indicating which normal station is the normal station requesting sharing of the processing. And a transmission processing unit for transmitting a transmission frame including the transmission unit to the normal station. The management station 1 performs distributed and centralized control by transmitting and receiving data to and from the plurality of normal stations.

Normally, the stations 2, 3, and 4, as shown in FIG.
It comprises a CPU 31, a ROM 32, a RAM 33, a transmission controller 34, a distributed control register 40, and an internal bus 35 connecting these. CPU
31, ROM 32, RAM 33, transmission controller 34
The internal bus 35 has the same function as that of the management station 1.

The respective CPUs 31 of the normal stations 2, 3, and 4
Is a functional block that determines whether centralized control or distributed control, a distributed control setting unit that displays the content of the determined control, and determines whether the function of the normal station is normal or abnormal. An abnormal display setting section indicating the processing, a processing sharing request display setting section for determining whether or not to request the sharing of processing executed by the normal station to another normal station, and displaying the processing, and a processing of the normal station. Priority determining unit for determining the priority order, a header portion indicating at least the transmission source and the transmission destination, a flag indicating normal or abnormal, a flag indicating the normal station itself, and other A transmission frame including a flag indicating whether or not to request sharing of the normal station and a data portion having a flag indicating which normal station is requesting the sharing of the processing is transmitted to the management station 1 or And a transmission processing unit for transmitting to other normal stations. There.

Each of the normal stations 2, 3, and 4 recognizes that the received data is valid data, and if it is not valid data, notifies the destination that the data is not valid data.

The priorities of the processes executed in the normal stations 2, 3, and 4 are not the same.
Normal station 3 has processing priority 2 and normal station 4 has processing priority 3
Is executed. Normal stations 2, 3, 4
Is a distributed control execution flag 41 of the distributed control register 40,
An abnormality flag 42 and a processing division flag 43 can be set. Further, the management station 1 can set the program execution flag 44 in the distribution control register 40.

First, the normal station 2 becomes abnormal, and the normal station 2 sets the abnormal flag 42 to the distributed control register 40.
The case when the setting cannot be set will be described. That is, when the power of the normal station 2 in which the abnormality has occurred is turned off, or when the cable is disconnected, the abnormality flag is noise, the communication signal is attenuated, and so on, the abnormality flag cannot be transferred to the management station 1. It is an explanation.

In FIG. 1, the management station 1 has a normal station 2, a normal station 3, and a normal station 4 connected to the network and determines whether each of the normal stations 2, 3, and 4 is normal or abnormal. Are transmitted at regular intervals to confirm the polling, and polling is performed.

The management station 1 continues this communication until an abnormal communication station is found among the normal stations 2, 3, and 4. In this example, since the normal station 2 is abnormal, the management station 1 performs polling until the normal station 2 confirms that there is no response.

When the management station 1 recognizes that the normal station 2 has not responded, the management station 1 sets an abnormality flag of 1 to the transmission partner station abnormality flag 45 of the transmission frame 49. Then, 2 indicating the normal station 2 is set in the transmission destination station command 46 by byte data, and the other normal stations 3 connected on the network are set.
The broadcast is transmitted to the normal station 4 in a transmission frame 50.

The normal station 3 and the normal station 4 transmit the transmission frame 50
Transmission destination station abnormality flag 45, transmission destination station command 46
Is received, the normal station 2 recognizes that an abnormality has occurred, and disconnects the normal station 2 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do.

That is, in the transmission frame 52, a flag 70 indicating the stop of the process is set to 3 indicating the stop, and a flag 71 indicating the priority of the process to be stopped is set to the third priority.

Normal station 4 transmits transmission frame 5 from management station 1.
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs a program for causing the normal station 4 to execute the processing of the processing priority 1 which has been executed by the normal station 2 with the transmission frame 53.

That is, in the transmission frame 53, the install flag 72 is set to a flag 1 indicating installation, and the flag 73 indicating a program of the process to be installed is set to the program 1 of the first priority. Thereafter, the management station 1 sets the program execution flag 44 in the distribution control register 40.

When the ordinary station 4 confirms that the program execution flag 44 has been set in the distribution control register 40,
The distribution control execution flag 41 is set to 1 indicating execution in the distribution control register 40 (0 if not executed). And normal station 4
Is the abnormality flag 4 set in the distribution control register 40.
2. The processing division flag 43 and the program execution flag 44 are cleared, and the processing of the processing priority 1 is executed.

When the abnormal normal station 2 becomes normal, the management station 1 connects to the other normal stations 3 and 4. In this case, the restored normal station 2 may instruct the normal station 2 to execute the processing of the processing priority 3 or change the processing executed by the normal station 4 to the processing of the priority 3 and send the processing to the normal station 2. The process of the first priority may be executed.

With the above operation, the processing priority 1
When the abnormality occurs in the normal station 2 and the abnormality flag 42 cannot be set in the distribution control register 40, the management station 1 substitutes the transmission partner station abnormality flag 4 for the substitute of the normal station 2 in which the abnormality has occurred.
5. By setting the transmission partner station command 46,
The processing of the processing priority 1 can be shifted and executed by the normal station having the lower processing priority.

Next, a case where the normal station 3 becomes abnormal will be described. FIG. 4 is an operation block diagram when the normal station 3 becomes abnormal in the first embodiment and the normal station 3 cannot set the abnormality flag 42 in the distributed control register 40. That is, when the power of the normal station 3 in which the abnormality has occurred is turned off, or when the cable is disconnected, the abnormality flag is noise, the communication signal is attenuated, and the abnormality flag cannot be transferred to the management station.

First, the management station 1 sends a transmission frame 49 to the normal station 2, the normal station 3, and the normal station 4 connected to the network to confirm whether it is normal or abnormal.
Is transmitted at regular intervals and polling is performed. This communication is continued until an abnormal station is found. In this example, since the normal station 3 is abnormal, polling is performed until it is confirmed that the normal station 3 has not responded.

When the management station 1 recognizes that the normal station 3 has not responded, the management station 1 sets the abnormal flag 1 in the transmission partner station abnormality flag 45, and sets 3 indicating the normal station 3 to byte data in the transmission partner station command 46. The broadcast is transferred to the other normal stations 2 and 3 connected on the network by the transmission frame 50.

The normal station 2 and the normal station 4 transmit the transmission frame 50
When the transmission destination station abnormality flag 45 and the transmission destination station command 46 are received, the normal station 3 recognizes that an abnormality has occurred in the normal station 3 and disconnects the normal station 3 connected to the network.

Thereafter, the management station 1 transmits a transmission frame for stopping the processing of the processing priority 3 executed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. Transfer 52. That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

Normal station 4 transmits transmission frame 5 from management station 1.
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs, in the transmission frame 53, a program for causing the normal station 4 to execute the processing of the processing priority 2 which has been executed by the normal station 3.

That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 2 of priority 2. Thereafter, the management station 1 sets the program execution flag 44 in the distribution control register 40.

When the normal station 4 confirms that the program execution flag 44 has been set in the distribution control register 40,
The distribution control execution flag 41 is set in the distribution control register 40, the abnormality flag 42, the processing division flag 43, and the program execution flag 44 are cleared, and the processing of the processing priority 2 is executed.

When the abnormal station 3 becomes normal, the management station 1 connects to the other normal stations 2 and 4. In this case, the restored normal station 3 may instruct the normal station 3 to execute the processing of the processing priority 3, or may change the processing executed by the normal station 4 to the processing of the priority 3, and instruct the normal station 3 to perform the processing. The process of the priority 2 may be executed.

With the above operation, the processing priority 2
In the case where an abnormality occurs in the normal station and the abnormality flag 42 cannot be set in the distribution control register 40, the processing of the processing priority 2 can be shifted to the normal station having the lower processing priority.

Next, although the normal station 2 is abnormal, the normal station 2 itself can set the abnormality flag 42, and the management station 1 also replaces the normal station 2 with the transmission partner station abnormality flag 45 and the transmission partner station. The case where the command 46 can be set will be described with reference to FIG.

The management station 1 sends the normal stations 2, 3 and 4 connected to the network to the normal stations 2, 3, and 4, respectively.
The transmission frame 49 is transferred at regular intervals to check whether the data No. 4 is normal or abnormal, and polling is performed.

The management station 1 continues this communication until an abnormal communication station is found among the normal stations 2, 3, and 4. In this example, since the normal station 2 is abnormal and the normal station 2 itself sets the abnormality flag 42, the management station 1 recognizes that the normal station 2 is abnormal.

When the management station 1 recognizes that the normal station 2 is abnormal, the management station 1 sets an abnormal flag of 1 to the transmission partner station abnormal flag 45 of the transmission frame 49. Then, 2 indicating the normal station 2 is set in the transmission destination station command 46 by byte data, and the other normal stations 3 connected on the network are set.
The broadcast is transmitted to the normal station 4 in a transmission frame 50.

The normal station 3 and the normal station 4 transmit the transmission frame 50
Transmission destination station abnormality flag 45, transmission destination station command 46
Is received, the normal station 2 recognizes that an abnormality has occurred, and disconnects the normal station 2 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do. That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

The management station 1 transfers the transmission frame 51 to the normal station 2. In the transmission frame 51, a flag 70 indicating processing stop is set to 3 indicating stop, and a flag 71 indicating priority of the processing to be stopped is set to 1 priority.

The normal station 4 sends the transmission frame 5
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs a program for causing the normal station 4 to execute the processing of the processing priority 1 which has been executed by the normal station 2 with the transmission frame 53. That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 1 of the priority order 1. afterwards,
The management station 1 sets the program execution flag 44 in the distribution control register 40.

When the normal station 4 confirms that the program execution flag 44 has been set in the distribution control register 40,
The distribution control execution flag 41 is set in the distribution control register 40. Then, the normal station 4 clears the abnormality flag 42, the processing division flag 43, and the program execution flag 44 set in the distribution control register 40, and executes the processing of the processing priority 1.

Then, when the normal station 2 that has become abnormal becomes normal, the management station 1 connects to the other normal stations 3 and 4. In this case, the restored normal station 2 may instruct the normal station 2 to execute the processing of the processing priority 3 or change the processing executed by the normal station 4 to the processing of the priority 3 and send the processing to the normal station 2. The process of the first priority may be executed.

By the above operation, the normal station 2 can set the abnormality flag 42, and the management station 1 can set the transmission partner station abnormality flag 45 and the transmission partner station command 46 instead of the normal station 2. Can also perform appropriate processing.

Next, although the normal station 3 is abnormal, the normal station 3 itself can set the abnormality flag 42, and the management station 1 also replaces the normal station 3 with the transmission partner station abnormality flag 45 and the transmission partner station. The case where the command 46 can be set will be described with reference to FIG.

The management station 1 sends the normal stations 2, 3, 3 and 4 connected to the network to the normal stations 2, 3, and 4, respectively.
The transmission frame 49 is transferred at regular intervals to check whether the data No. 4 is normal or abnormal, and polling is performed.

The management station 1 continues this communication until an abnormal communication station is found among the normal stations 2, 3, and 4. In this example, since the normal station 3 is abnormal and the normal station 3 itself has set the flag 42, the management station 1 recognizes that the normal station 3 is abnormal.

When the management station 1 recognizes that the normal station 3 is abnormal, the management station 1 sets an abnormal flag of 1 to the transmission partner station abnormal flag 45 of the transmission frame 49. Then, 3 indicating the normal station 3 is set in the transmission partner station command 46 by byte data, and the other normal stations 2 connected to the network
The broadcast is transmitted to the normal station 3 in a transmission frame 50.

The normal station 2 and the normal station 4 transmit the transmission frame 50
Transmission destination station abnormality flag 45, transmission destination station command 46
Is received, the normal station 3 recognizes that an abnormality has occurred, and disconnects the normal station 3 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do. That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

The management station 1 transfers the transmission frame 51 to the normal station 3. In the transmission frame 51, a flag 70 indicating processing stop is set to 3 indicating stop, and a flag 71 indicating priority of the processing to be stopped is set to 2 priority.

The normal station 4 sends the transmission frame 5
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs, in the transmission frame 53, a program for causing the normal station 4 to execute the processing of the processing priority 2 which has been executed by the normal station 3.

That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 2 of priority 2. Thereafter, the management station 1 sets the program execution flag 44 in the distribution control register 40.

When the normal station 4 confirms that the program execution flag 44 has been set in the distribution control register 40,
The distribution control execution flag 41 is set in the distribution control register 40. Then, the normal station 4 clears the abnormal flag 42, the processing division flag 43, and the program execution flag 44 set in the distribution control register 40, and executes the processing of the processing priority order 2.

When the abnormal station 3 becomes normal, the management station 1 connects to the other normal stations 2 and 4. In this case, the restored normal station 3 may instruct the normal station 3 to execute the processing of the processing priority 3, or may change the processing executed by the normal station 4 to the processing of the priority 3, and instruct the normal station 3 to perform the processing. The process of the priority 2 may be executed.

By the above operation, the normal station 3 can set the abnormality flag 42, and the management station 1 can set the transmission partner station abnormality flag 45 and the transmission partner station command 46 instead of the normal station 3. Can also perform appropriate processing.

FIG. 7 is a schematic configuration diagram of a distributed control apparatus according to a second embodiment of the present invention, and is an example in which a process when a load on a normal station becomes large can be appropriately executed. In the second embodiment, the overall configuration and the internal configuration are almost the same as those shown in FIGS. 1, 2 and 3 showing the above-described first embodiment. And the description thereof is omitted.

In the second embodiment, as in the first embodiment, the priorities of the processes executed in the normal stations 2, 3, and 4 are not the same, and
Is a processing priority 1, the normal station 3 is executing a processing priority 2, and the normal station 4 is executing a processing priority 3.

The CPs of the normal stations 2, 3, and 4
U31 further includes an excess display setting unit that determines whether the processing performed by the normal station is excessive, and indicates whether the processing is excessive. Further, the management station 1 determines that the normal station is excessive when there is no response to the data transfer to each normal station and when the excess is set in the excess display setting section of each normal station. And an overload judging unit.

Further, the data portion of the transmission frame transmitted by the transmission processing section of the CPU 31 of the normal stations 2, 3, 4 and the management station 1 indicates a flag indicating whether or not the data is overloaded and whether or not the data is overloaded. The normal station has a flag indicating which normal station.

First, processing division when the load on the normal station 2 becomes heavy and the normal station 2 cannot set the processing division flag 43 in the distributed control register 40 will be described. That is, when the power of the normal station 2 in which the load overload occurs is turned off, or the cable is disconnected, the load overload flag is a noise, the communication signal is attenuated, and the abnormal flag is transmitted to the management station 1,
This is a description of processing when transfer cannot be performed.

In FIG. 7, the management station 1 provides a normal station 2, a normal station 3, and a normal station 4 connected to the network that the normal stations 2, 3, and 4 are overloaded or not overloaded. The transmission frame 49 is transferred at regular intervals in order to check whether the polling has been performed, and polling is performed.

The management station 1 continues this communication until an overloaded station is found among the normal stations 2, 3, and 4. In this example, since the normal station 2 is overloaded, the management station 1 performs polling until the overloaded station 2 confirms that there is no response.

When the management station 1 recognizes that the normal station 2 has not responded, the management station 1 sets the overload flag 47 of the transmission partner station of the transmission frame 49 to the overload flag of 1. Then, 2 indicating the normal station 2 is set in the transmission destination station command 46 by byte data, and the other normal stations 3 connected on the network are set.
The broadcast is transmitted to the normal station 4 in a transmission frame 50.

The normal station 3 and the normal station 4 transmit the transmission frame 50
Transmission destination station overload flag 47, transmission destination station command 46
Is received, the normal station 2 recognizes that a load overload has occurred, and disconnects the normal station 2 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do. That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

Normal station 4 transmits transmission frame 5 from management station 1.
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs a program for causing the normal station 4 to execute the processing of the processing priority 1 which has been executed by the normal station 2 with the transmission frame 53. That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 1 of the priority order 1. afterwards,
The management station 1 sets the program execution flag 44 in the distribution control register 40.

When the ordinary station 4 confirms that the program execution flag 44 has been set in the distribution control register 40, it sets the distribution control execution flag 41 in the distribution control register 40. Then, the normal station 4 sets the processing division flag 43 and the program execution flag 44 set in the distribution control register 40.
Is cleared, and the processing of the processing priority 1 is executed.

Then, when the load of the normal station 2, which has been overloaded, becomes normal, the management station 1 connects to the other normal stations 3, 4. In this case, the restored normal station 2 may instruct the normal station 2 to execute the processing of the processing priority 3 or change the processing executed by the normal station 4 to the processing of the priority 3 and send the processing to the normal station 2. The process of the first priority may be executed.

By the above operation, the processing priority 1
When a load overload occurs in the normal station 2 and the processing division flag 43 cannot be set in the distributed control register 40, the management station 1
By setting the transmission partner station load overload flag 47 and the transmission partner station command 46 on behalf of the normal station 2 in which the load overload occurs, the processing of the processing priority 1 is shifted to the normal station having the lower processing priority. Can be performed.

Next, a description will be given of the processing division of labor when the load of the normal station 3 becomes heavy and the normal station 3 cannot set the processing division flag 43 in the distributed control register 40. That is, when the power of the normal station 3 in which the load overload occurs is cut off, or the cable is disconnected, the load overload flag is a noise, the communication signal is attenuated, and the abnormality flag is transmitted to the management station 1.
This is a description of processing when transfer cannot be performed.

In FIG. 8, the management station 1 provides a normal station 2, a normal station 3, and a normal station 4 connected to the network that each of the normal stations 2, 3, and 4 is overloaded or not overloaded. The transmission frame 49 is transferred at regular intervals in order to check whether the polling has been performed, and polling is performed.

The management station 1 continues this communication until an overloaded station is found among the normal stations 2, 3, and 4. In this example, since the normal station 3 is overloaded, the management station 1 performs polling until the overloaded station 3 confirms that there is no response.

When the management station 1 recognizes that the normal station 3 does not respond, the management station 1 sets the overload flag 47 of the transmission partner station of the transmission frame 49 to the overload flag of 1. Then, 3 indicating the normal station 3 is set in the transmission partner station command 46 by byte data, and the other normal stations 2 connected to the network
The broadcast is transmitted to the normal station 4 in a transmission frame 50.

The normal station 2 and the normal station 4 transmit the transmission frame 50
Transmission destination station overload flag 47, transmission destination station command 46
Is received, the normal station 3 recognizes that a heavy load has occurred, and disconnects the normal station 3 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do. That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

The normal station 4 sends the transmission frame 5
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs, in the transmission frame 53, a program for causing the normal station 4 to execute the processing of the processing priority 2 which has been executed by the normal station 3.

That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 2 of priority 2. Thereafter, the management station 1 sets the program execution flag 44 in the distribution control register 40.

When the normal station 4 confirms that the program execution flag 44 has been set in the distribution control register 40, it sets the distribution control execution flag 41 in the distribution control register 40. Then, the normal station 4 sets the processing division flag 43 and the program execution flag 44 set in the distribution control register 40.
Is cleared, and the processing of the processing priority 2 is executed.

When the load on the normal station 3 which has been overloaded becomes normal, the management station 1 connects to the other normal stations 2 and 4. In this case, the restored normal station 3 may instruct the normal station 3 to execute the processing of the processing priority 3, or may change the processing executed by the normal station 4 to the processing of the priority 3, and instruct the normal station 3 to perform the processing. The process of the priority 2 may be executed.

By the operation as described above, the processing priority 2
When the load overload occurs in the normal station 3 and the processing division flag 43 cannot be set in the distributed control register 40, the management station 1
By setting the transmission partner station load overload flag 47 and the transmission partner station command 46 on behalf of the normal station 3 in which the load overload has occurred, the processing of the processing priority 2 is shifted by the normal station having the lower processing priority. Can be performed.

Next, when the load on the normal station 2 becomes heavy, the normal station 2 can set the processing division of work flag 43 in the distributed control register 40, and the management station 1 is replaced with the normal station 2 instead. The case where the transmission partner station overload flag 47 and the transmission partner station command 46 can be set will be described.

In FIG. 9, the management station 1 provides a normal station 2, a normal station 3, and a normal station 4 connected to the network that each of the normal stations 2, 3, and 4 is overloaded or not overloaded. The transmission frame 49 is transferred at regular intervals in order to check whether the polling has been performed, and polling is performed.

The management station 1 continues this communication until an overloaded station is found among the normal stations 2, 3, and 4. In this example, since the normal station 2 is overloaded, the normal station 2 sets the processing division flag 43 of the control register 40 to 1 indicating a processing division request.

When the management station 1 recognizes that the processing division flag 43 of the load overload station 2 is 1, the management frame 1 transmits the transmission frame 50.
The overload flag 47 is set to the overload flag 47 of the transmission partner station. Then, 2 indicating the normal station 2 is set in the transmission partner station command 46 by byte data, and the transmission frame 50 is transmitted to the other normal stations 3 and 4 connected to the network.
To broadcast.

The normal station 3 and the normal station 4 transmit the transmission frame 50
Transmission destination station overload flag 47, transmission destination station command 46
Is received, the normal station 2 recognizes that a load overload has occurred, and disconnects the normal station 2 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do.

That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

The normal station 4 transmits the transmission frame 5 from the management station 1.
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs a program for causing the normal station 4 to execute the processing of the processing priority 1 which has been executed by the normal station 2 with the transmission frame 53. That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 1 of the priority order 1. afterwards,
The management station 1 sets the program execution flag 44 in the distribution control register 40.

When the ordinary station 4 confirms that the program execution flag 44 has been set in the distribution control register 40, the normal station 4 sets the distribution control execution flag 41 in the distribution control register 40. Then, the normal station 4 sets the processing division flag 43 and the program execution flag 44 set in the distribution control register 40.
Is cleared, and the processing of the processing priority 1 is executed.

Then, when the load of the normal station 2, which has been overloaded, becomes normal, the management station 1 connects to the other normal stations 3, 4. In this case, the restored normal station 2 may instruct the normal station 2 to execute the processing of the processing priority 3 or change the processing executed by the normal station 4 to the processing of the priority 3 and send the processing to the normal station 2. The process of the first priority may be executed.

With the above operation, the processing priority 1
Even if a load overload occurs in the normal station 2 and the processing division of work flag 43 can be set in the distribution control register 40, the processing of the processing priority 1 can be shifted and executed by the normal station having the lower processing priority.

Next, when the load on the normal station 3 becomes heavy, the normal station 3 can set the processing division of work flag 43 in the distributed control register 40, and the management station 1 transmits instead of the normal station 3 instead of the normal station 3. Destination station overload flag 47 and transmission destination station command 4
6 will be described.

In FIG. 10, a management station 1 sends a request to a normal station 2, a normal station 3, and a normal station 4 connected to a network.
In order to confirm whether each of the normal stations 2, 3, and 4 is overloaded or not overloaded, the transmission frame 49 is transferred at regular intervals and polling is performed.

The management station 1 continues this communication until an overloaded station is found among the normal stations 2, 3, and 4. In this example, since the normal station 3 is overloaded, the normal station 3 sets the processing division flag 43 of the control register 40 to 1 indicating a processing division request.

When the management station 1 recognizes that the processing division flag 43 of the overloaded station 3 is 1, the transmission frame 50
The overload flag 47 is set to the overload flag 47 of the transmission partner station. Then, 3 indicating the normal station 3 is set in the transmission destination station command 46 by byte data, and the transmission frame 50 is transmitted to the other normal stations 2 and 4 connected to the network.
To broadcast.

The normal station 2 and the normal station 4 transmit the transmission frame 50
Transmission destination station overload flag 47, transmission destination station command 46
Is received, the normal station 3 recognizes that a heavy load has occurred, and disconnects the normal station 3 connected to the network. Thereafter, the management station 1 transfers the transmission frame 52 for stopping the processing of the processing priority 3 performed by the normal station 4 to the normal station 4 of the processing priority 3 having the lowest processing priority. I do. That is, in the transmission frame 52, the flag 70 indicating the stop of the process is set to 3 indicating the stop, and the flag 71 indicating the priority of the process to be stopped is set to the third priority.

The normal station 4 sends the transmission frame 5 from the management station 1.
When the station 2 is received, the processing of the processing priority 3 executed by the normal station 4 is stopped. After that, the management station 1 installs, in the transmission frame 53, a program for causing the normal station 4 to execute the processing of the processing priority 2 which has been executed by the normal station 3. That is, in the transmission frame 53, the installation flag 72 is set to the flag 1 indicating installation, and the flag 73 indicating the program of the processing to be installed is set to the program 2 of priority 2. afterwards,
The management station 1 sets the program execution flag 44 in the distribution control register 40.

When the ordinary station 4 confirms that the program execution flag 44 has been set in the distribution control register 40, it sets the distribution control execution flag 41 in the distribution control register 40. Then, the normal station 4 sets the processing division flag 43 and the program execution flag 44 set in the distribution control register 40.
Is cleared, and the processing of the processing priority 2 is executed.

Then, when the load of the normal station 3, which has been overloaded, becomes normal, the management station 1 connects to the other normal stations 2, 4. In this case, the restored normal station 3 may instruct the normal station 3 to execute the processing of the processing priority 3, or may change the processing executed by the normal station 4 to the processing of the priority 3, and instruct the normal station 3 to perform the processing. The process of the priority 2 may be executed.

With the above operation, the processing priority 2
Even if a load overload occurs in the normal station 3 and the processing division flag 43 can be set in the distribution control register 40, the processing of the processing priority 2 can be shifted and executed by the normal station having the lower processing priority.

In the above-described embodiment, each of the transmission frames 49, 50, 51, 52, and 53 includes a header section and a data section, and includes, in the data section, a transmission partner station abnormality flag 45 and a transmission partner station command 46. , Transmission partner station overload flag 47, processing stop flag 70, processing priority flag 7
1, installation flag 72, processing program flag 7
Although 3 is set, the same effect can be obtained by setting these commands and flags in the header section instead of the data section.

[0128]

The present invention is configured as described above and has the following effects. When an abnormal flag cannot be transferred from the normal station where the error occurred to the control station, the control station transfers the error flag and the normal station where the error occurred to another communication station on the network on behalf of the management station, and the processing priority. The process currently being performed by the other normal station having the lowest value can be stopped, and the process of the normal station in which an abnormality has occurred can be performed.

Therefore, the normal station in which no abnormality has occurred can perform the high-priority processing of the other station in the abnormal state while performing the low-priority distributed function in the normal state. The configuration has an effect that a highly reliable distributed control device can be configured. Therefore, even under the condition of the network where the number of connections is limited, there is an effect that the super-dispersion control, the expansion / contraction operation control, and the degeneration operation control system can be configured with an inexpensive configuration.

Also, when the load-overload flag cannot be transferred from the normal station in which the load overload has occurred to the control station, the control station substitutes the load overload flag and the normal load overload on the other communication station on the network. To the other normal station having the lowest processing priority, to stop the processing currently being performed, and to cause the normal station having the overloaded load to perform the processing.

Therefore, a normal station in which no load overload occurs can perform a high priority processing of another station when the load is overload while performing a low priority distribution function in a normal state. There is an effect that a highly reliable distributed control device can be easily configured with an inexpensive configuration. Therefore, even under the condition of the network where the number of connections is limited, there is an effect that the super-dispersion control, the expansion / contraction operation control, and the degeneration operation control system can be configured with an inexpensive configuration.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a distributed control device according to a first embodiment of the present invention.

FIG. 2 is an internal configuration diagram of a management station in the example of FIG.

FIG. 3 is an internal configuration diagram of a normal station in the example of FIG. 1;

FIG. 4 is an operation block diagram when the normal station 3 becomes abnormal and an abnormal flag cannot be set in the example of FIG. 1;

FIG. 5 is an operation block diagram when the normal station 2 is abnormal but an abnormal flag can be set in the example of FIG. 1;

FIG. 6 is an operation block diagram in a case where the normal station 3 is abnormal but an abnormal flag can be set in the example of FIG. 1;

FIG. 7 is a schematic configuration diagram of a distributed control device according to a second embodiment of the present invention.

8 is an operation block diagram when the load on the normal station 3 is heavy and the processing division flag cannot be set in the example of FIG. 7;

9 is an operation block diagram in a case where the load on the normal station 2 is heavy and a processing division flag can be set in the example of FIG. 7;

FIG. 10 is an operation block diagram in a case where the load on the normal station 3 becomes heavy and a processing division flag can be set in the example of FIG. 7;

FIG. 11 is a schematic configuration diagram of a conventional distributed switching system.

FIG. 12 is a schematic configuration diagram of an example of a distributed control device that can cope with an abnormality.

[Explanation of symbols]

 1 Management Station 2, 3, 4 Normal Station 30 Transmission Line 31 CPU 32 ROM 33 RAM 34 Transmission Controller 35 Internal Bus 36 External ROM 37 External RAM 38 Memory Expansion Bus 40 Distributed Control Register 41 Distributed Control Execution Flag 42 Abnormal Flag 44 Program Execution Flag 45 Transmission partner station abnormality flag 46 Transmission partner station command 47 Transmission partner station overload flag 49-53 Transmission frame

Claims (6)

[Claims] 1. A plurality of normal stations for distributed control for recognizing that received data is valid data, and when the data is not valid data, notifying the transmission destination that the data is not valid. In a distributed control device having a management station that performs distributed and centralized management control by transmitting and receiving data to and from a normal station, each of the plurality of normal stations determines whether to perform centralized control or distributed control, and displays the determined control content. A distributed control setting unit, an abnormality display setting unit that determines whether the function of the normal station is normal or abnormal, and indicates whether the function is normal or abnormal, and a division of processing executed by the normal station to other normal stations. A process sharing request display setting unit that determines whether or not to make a request, and includes a priority determination unit that determines the priority of the process of the normal station among the distributed control processes of the plurality of normal stations. The above management bureau When there is no response to the data transfer to each normal station, and when an abnormality is set in the abnormality display setting section of each of the above normal stations, an abnormality determination section is provided to determine that the normal station is abnormal. A distributed control apparatus characterized by the above-mentioned. 2. The distributed control apparatus according to claim 1, wherein each of the normal station and the management station respectively includes a header portion indicating at least a transmission source and a transmission destination, a flag indicating normal or abnormal, and a flag indicating normal or abnormal. A distributed processing unit for transmitting a transmission frame composed of a data section having a flag indicating which normal station is a normal station indicating whether it is abnormal to another normal station or a management station. apparatus. 3. The distributed control device according to claim 2, wherein the data portion of the transmission frame includes a flag indicating whether or not to request the sharing of the processing being executed to another normal station, A distributed control apparatus characterized by further comprising a flag indicating which of the normal stations has requested sharing. 4. A plurality of normal stations for distributed control for recognizing that the received data is valid data, and when the data is not valid data, notifying the transmission destination that the data is not valid; In a distributed control device having a management station that performs distributed and centralized management control by transmitting and receiving data to and from a normal station, each of the plurality of normal stations determines whether to perform centralized control or distributed control, and displays the determined control content. A distributed control setting unit, an overload display setting unit that determines whether the processing performed by the normal station is overloaded, and an overload display setting unit that indicates whether the processing is overloaded. A process sharing request display setting unit that determines whether or not to request sharing, and a priority determining unit that determines the priority of the process of the normal station among the distributed control processes of the plurality of normal stations. Prepared, In the case where there is no response to the data transfer to each of the normal stations, and in the case where the excess is set in the excess display setting section of each of the normal stations, the excess determining section which determines that the normal station is excessive is provided. A distributed control device, comprising: 5. The distributed control device according to claim 4, wherein each of the normal station and the management station respectively includes a header portion indicating at least a transmission source and a transmission destination, a flag indicating whether or not the packet is overloaded, and a flag indicating whether or not the packet is overloaded. A transmission section comprising a data section having a flag indicating which of the normal stations indicates the normal station and a transmission section to another normal station or management station. apparatus. 6. The distributed control device according to claim 5, wherein the data portion of the transmission frame includes a flag indicating whether or not to request the other normal station to share the processing being executed, A distributed control apparatus characterized by further comprising a flag indicating which of the normal stations has requested sharing.