JP2006236371A - Control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency of a control operation in a control system. <P>SOLUTION: This control system 35 has an input/output device 40, a common storage means 41 storing control data, a service system control device 36 storing the control data used for control processing based on the data received from the input/output device 40 in a common storage means 42, a standby system control device 37 reading the control data stored in the common storage means 41 for performing control processing in the case of a failure of the service system control device 36, and a switch means 38 managing for preventing overlap between access to the input/output device 40 by the service system control device 36 and that by the standby system control device 37. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for realizing efficient control of public systems such as steel plants, paper manufacturing plants, and water and sewage systems, and industrial systems used in the automobile industry.

  In some cases, by simultaneously using a plurality of control devices while sharing an input / output device that outputs data to the control target or inputs data from the control target, the processing capacity of the industrial control device may be improved.

  FIG. 11 is a block diagram showing a configuration of a conventional control system in which a plurality of control devices share an input / output device.

  In this conventional control system 1, the control devices 2 and 3 share the I / O bus 4, and the control devices 2 and 3 can arbitrarily access the input / output device 5 via the I / O bus 4. It is. The input / output device 5 collects data from the controlled object 6 and provides the data to the controlled object.

  Each of the control devices 2 and 3 and the input / output device 5 include data memories 7 and 8 and an I / O memory 9 for storing I / O data (input / output data), respectively.

  When the input / output device 5 is accessed by the control device 2, the I / O data on the data memory 7 is stored in the I / O memory 9 via the I / O bus 4, or the I / O data on the I / O memory 9 is / O data is stored in the data memory 7 via the I / O bus 4. As a result, data is transferred between the control device 2 and the controlled object.

  The case where the input / output device 5 is accessed by the control device 3 is the same as the case of the control device 2 described above, and I / O data is transferred between the data memory 8 and the I / O memory 9.

  FIG. 12 is a block diagram showing a state of data transfer in the conventional control system 1.

  The I / O memory 9 includes an area 9 a for the control device 2, an area 9 b for the control device 3, and a shared area 9 c for both the control devices 2 and 3.

  The control device 2 receives the I / O data read from the area 9a or the common area 9c for the control device 2 and stores it in the data memory 7, and transmits the I / O data in the data memory 7 for control. It memorize | stores in the area | region 9a for apparatus 2, and the shared area 9c.

The control device 3 also transfers data to and from the input / output device 5 in the same manner as the control device 2 described above.
JP 58-056018 A JP-A-62-226312 Japanese Patent Application Laid-Open No. 08-249021

  In the above control system, a plurality of control devices can arbitrarily access the input / output device.

  However, since there is no restriction on the timing at which each control device accesses the input / output device, each control device accesses the input / output device 5 at an individual timing, and access cannot be synchronized between the control devices. A collision may occur.

  Further, when a plurality of control devices execute the same control program using I / O data from the shared input / output device, the same I / O data input timing by each control device may be the same. Even if the same control program is executed using I / O data, the control results may not be consistent.

  For example, when a certain control device accesses the input / output device, the input / output device updates the contents of the I / O data, and then when another control device accesses the input / output device, the same control processing based on the same I / O data Even so, the consistency of the results is not ensured between the control devices. Such inconsistency of control results becomes inconvenient when a plurality of control devices execute control in cooperation.

  Further, in the conventional control system, when each control device inputs the same I / O data from the same input / output device, it is necessary to input data for the number of control devices, and access to the input / output devices. There is a problem of increasing waste. In particular, the I / O access to the input / output device generally requires 100 times or more time than the access to the memory, and takes an access time.

  In addition, there is a problem that there is no effective method for verifying a control program executed by the control device in a state where no control target or input / output device is installed.

  In addition, when performing control multiplexed by a plurality of control devices, a special multiplexing control device for transferring data in the middle of the control between the control devices or switching the control devices is required, resulting in a complicated configuration. There is a problem of becoming.

  The present invention has been made in view of the above circumstances, and an object thereof is to manage access to an access destination and improve the efficiency of control in a control system.

  Specific means taken for realizing the present invention will be described below.

  A control system according to a first example of the present invention is a control system including an input / output device, and is a shared storage means for storing data and a control used for control processing based on data received from the input / output device. A normal control device that stores data in the shared storage means, and a standby control device that reads the control data stored in the shared storage means and executes control processing when the normal control device fails. And switching means for managing the access to the input / output device by the normal control device and the standby control device so as not to overlap each other.

  As a result, even if one of the plurality of control devices fails, the control data up to that point is stored in the shared storage means, so that another control device is stored in the shared storage means. Using the control data, the operation of the failed control device can be quickly taken over.

  Therefore, for example, even if the normal control device fails, it can be immediately switched to the standby control device. In this case, since the standby control device can use the latest control data of the regular control device, the control data is transferred between the two control devices and the content is constantly updated (hereinafter referred to as “tracking”). And the tracking time, tracking circuit, and tracking process can be eliminated.

  In the control system of the second example, in the control system of the first example, the control device of the regular system executes the first control program, and the control device of the standby system performs the same control processing as the first control program. A second control program that is implemented and operates in parallel with the first control program is executed.

  In this second example, in addition to the same effects as the control system of the first example, the same control processing is executed in parallel among a plurality of control devices. Can continue.

  The control system of the third example is a control system including an input / output device, and includes shared storage means for storing transmission data transmitted to the input / output device and reception data received from the input / output device, and shared storage. A plurality of control devices for reading the received data stored in the means and storing the transmission data in the shared storage means; and a data transfer means for transferring the data between the input / output device and the shared storage means.

  In this third example, data from the plurality of control devices to the input / output devices and data from the input / output devices to the plurality of control devices are temporarily stored in the shared storage means. Then, the data transmission means independent of the control device transfers data between the shared storage means and the input / output device.

  This makes it possible to multiplex a plurality of control devices, and even when the number of control devices increases or decreases, there is no need to change the management method related to access, so it is easy to change the number of control devices. It can correspond to.

  Further, for example, by executing different control programs in parallel in the respective control devices, the execution speed can be improved as compared with the case of executing different control programs individually.

  Further, for example, the same program can be stored in a plurality of control devices, and an arbitrary control device can be used as a regular system and another control device can be used as a standby system. In this case, if the standby control device also executes the control program simultaneously with the regular control device and stores the result in the shared storage means, the data transfer means can control the standby system even if the regular control device fails. Data from the device may be transferred between the shared storage means and the input / output device.

  In the control system of the fourth example, in the control system of the third example, the data transfer means transmits the data to be transmitted to the input / output device stored in the shared storage means at predetermined intervals or at arbitrary timing. Means for transmitting to the apparatus, and means for receiving data to be received by any of the plurality of control devices from the input / output device at predetermined intervals or at arbitrary timing and storing them in the shared storage means.

  Thereby, the same effect can be obtained by the same operation as in the third example.

  As described above in detail, when the present invention is applied, the operation of the control system including the control device and the input / output device accessed by the control device can be made efficient.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In the present embodiment, a description will be given of a control system in which a specific control device performs proxy data input / output with respect to an input / output device to be executed by another control device.

  FIG. 1 is a block diagram showing a configuration of a control system according to the present embodiment.

  In this control system 10, an access proxy control device 11, an access request control device 12, and a shared memory 13 accessible from the control devices 11 and 12 are connected via a microcomputer bus 16. The access proxy control device 11 is connected to the input / output device 17 via the I / O bus 4, and only the access proxy control device 11 can access the input / output device 17.

  The shared memory 13 includes an area 13 a for I / O data handled by the control device 11 and an area 13 b for I / O data handled by the control device 12.

  The access proxy control device 11 performs proxy access to the shared input / output device 17 instead of the access request control device 12 at predetermined intervals or when an interrupt request signal is input. An access proxy unit 11 a is provided, and a data memory 14 is provided.

  The access request control device 12 includes a data memory 15 and can transmit and receive data to and from the input / output device 17 by using access proxy execution by the access proxy control device 11. Further, when the access request control device 12 requests access to the input / output device 17, the access request control device 12 outputs an interrupt signal to the access proxy control device 11.

  The control devices 11 and 12 share the microcomputer bus 16 and both can access the shared memory 13 on the microcomputer bus 16 and each include a microcomputer and a memory in the central part.

  The input / output device 17 includes an I / O memory 18. The I / O memory 18 includes a region 18a for the control device 11, a region 18b for the control device 12, and a shared region 18c for both the control devices 11 and 12. including.

  FIG. 2 is a block diagram showing a state of data transfer executed by the control system 10 according to the present embodiment.

  In this control system 10, only the access proxy control device 11 directly accesses the input / output device 17.

  The control device 11 transfers I / O data between its own data memory 14 and the areas 18 a and 18 c of the I / O memory 18 of the input / output device 17.

  The access proxy unit 11 a included in the control device 11 stores the I / O data received from the region 18 a of the I / O memory 18 in the region 18 a for the control device 11 on the shared memory 13.

  In addition, the access proxy unit 11 a performs an I / O data transfer between the control device 12 and the input / output device 17 by proxy in an area of the I / O memory 18 of the input / output device 17 at predetermined intervals. The I / O data received from 18 b and 18 c is stored in the area 13 b for the control device 12 on the shared memory 13, and the I / O data stored in the area 13 b on the shared memory 13 is stored in the I / O memory 18. Are stored in the areas 18b and 18c.

  On the other hand, the control device 12 does not directly access the I / O data on the I / O memory 18 in the input / output device 17, and the control device 12 area 13 b on its own data memory 15 and shared memory 13. Transfer data to and from.

  Data transfer between the shared memory 13 and the data memory 15 of the control device 12 is executed using the microcomputer bus 16 instead of the I / O bus 4. Therefore, the control device 1 can access the shared memory faster than the control device 12 directly accesses the input / output device 17.

  Here, the operation when an interrupt signal is output from the control device 12 to the control device 11 will be described in detail.

  FIG. 3 is a block diagram showing a state of data transfer by an interrupt signal of the control system 10 according to the present embodiment.

  The access request control device 12 is data necessary for access to the specific area 13c on the shared memory 13 when the access request to the input / output device 17 is requested at predetermined intervals or at arbitrary timing. The access data for reception or transmission is stored, and an interrupt signal is transmitted to the access proxy controller 11.

  The access data for reception is data stored in the specific area 13 c when the control device 12 requests reception of I / O data from the input / output device 17, and the I / O data is received from the I / O memory 18. It includes data such as address to read, access type, number of words to be accessed.

  On the other hand, the transmission access data is data stored in the specific area 13c when the control device 12 transmits I / O data to the input / output device 17, and the I / O data, access type, and data transfer completion are stored. Data such as a handshake flag shown.

  When receiving the interrupt signal, the access proxy unit 11a refers to the specific area 13c and determines the type of access.

  When the access proxy unit 11 a determines that the access type is data reception, the access proxy unit 11 a reads I / O data on the I / O memory 18 indicated by the reception access data and stores the I / O data in the shared memory 13. The control device 12 reads the I / O data stored on the shared memory 13 and the access is completed.

  On the other hand, if the access proxy unit 11a determines that the access request is data transmission, the access proxy unit 11a reads the I / O data on the shared memory 13 after confirming the completion of the data transfer by the handshake flag on the shared memory 13, and The data is stored on the O memory 18, and the access is completed.

  As described above, in the control system 10 according to the present embodiment, when the plurality of control devices 11 and 12 share the input / output device 17, only the control device 11 accesses the input / output device 17. Access of other control devices 12 is executed by this control device 11 as a proxy.

  As a result, it is possible to synchronize the access performed from the control devices 11 and 12 to the input / output device 17 while realizing the same operation as when the control devices 11 and 12 directly access the input / output device 17. it can.

  Further, when the same I / O data is used between the control devices 11 and 12, the other control device 12 can use the I / O data accessed by the control device 11 as it is.

  Thereby, the number of accesses to the input / output device 17 can be reduced, and the data input / output time can be shortened. In addition, since control processing can be performed using the same I / O data between the control devices 11 and 12, consistency of control results can be ensured.

  In this embodiment, the case where there are two control devices has been described as an example. However, the access proxy control device 11 may be one and the access request control device 12 may be two or more. It is applicable similarly and can obtain the same effect. In this case, the other control device 12 that is not the control device 11 operates in the same manner as described above.

(Second Embodiment)
In the present embodiment, in the control system according to the first embodiment as described above, it is confirmed whether or not the control operation can be normally realized before actually accessing the input / output device. A simulation operation for this will be described.

  FIG. 4 is a block diagram showing a state of data transfer by the simulation operation in this embodiment. The same parts as those in FIGS. Only will be described in detail.

  When the control system 10 does not include the input / output device 17 or when the control device 11 and the input / output device 17 cannot transfer data, the control device 12 is used to verify the control program of the control device 11. It is used instead of the input / output device 17 as a simulator.

  When entering the simulation mode, the access proxy unit 1 of the control device 11 replaces the I / O memory 18 with the area 13a on the shared memory 13 for mapping the I / O data for the control device 11. to access.

  The control device 12 reads the I / O data in the area 13a on the shared memory 13 stored by the control device 11, and executes a simulation program 12a that simulates the control target 6 using this I / O data.

  The control device 12 stores simulation data, which is the execution result of the simulation program 12a, in the area 13a on the shared memory 13.

  The access proxy unit 11a of the control device 11 reads the simulation data from the area 13a on the shared memory 13 and determines whether the result is appropriate.

  By operating as described above, the control system according to the present embodiment can simulate the control program of the control device 11 even if the control device 11 is not connected to the input / output device 17 in an accessible manner. . Thereby, before actually performing control with respect to the control object 6, the suitability of the control processing by the control system can be determined.

  In the present embodiment, the case of simulation of one control device is described as an example, but the same simulation can be performed for a plurality of control devices.

(Third embodiment)
When the number of input / output devices is large, each control device may have a dedicated input / output device.

  In the present embodiment, a control system that realizes efficiency when a plurality of control devices each have a dedicated input / output device will be described.

  FIG. 5 is a block diagram showing the configuration of the control system according to the present embodiment.

  In the control system 19, the control devices 20 and 21 and the shared memory 22 are connected to each other via a microcomputer bus 23 so as to be able to transfer data.

  The control device 20 is connected to a self-dedicated input / output device 25 via an I / O bus 24 so as to be able to transfer data. Similarly, the control device 21 also has a self-dedicated input / output via an I / O bus 26. It is connected to the device 27 so as to be able to transfer data.

  The input / output device 25 includes an I / O memory 29 including an area 28 for the control device 20. Similarly, the input / output device 27 includes an I / O memory 31 including an area 30 for the control device 21.

  The control device 20 stores in the data memory 32 and the shared memory 22 the I / O data d1 that is transferred between the data memory 32 provided therein and the I / O memory 28 of the input / output device 25. Further, the control device 20 receives I / O data d2 that is transferred between the data memory 33 of the other control device 21 and the I / O memory 31 of the input / output device 27 from the shared memory 22, and the data Store in the memory 32.

  The control device 21 operates in the same manner as the control device 20, stores the I / O data d2 in the data memory 33 and the shared memory 22 provided therein, receives the I / O data d1 from the shared memory 22, and receives the data memory. 33.

  FIG. 6 is a block diagram showing a state of data transfer executed by the control system 19 according to the present embodiment.

  In the control system 19, the control device 20 transfers the I / O data d1 between the data memory 32 and the I / O memory 29 of the dedicated input / output device 25, and shares this I / O data d1 simultaneously with the transfer. It is also stored on the memory 22.

  Similarly, the control device 21 transfers the I / O data d2 between the data memory 33 and the I / O memory 31 of the dedicated input / output device 27. Simultaneously with the transfer, the control device 21 transfers the I / O data d2 on the shared memory 22. Also remember.

  Then, the control device 20 reads out the I / O data d2 on the shared memory 22 transferred by the other control device 21 as necessary, and stores it in the data memory 32.

  Similarly, the control device 21 reads out the I / O data d1 on the shared memory 22 transferred by the other control device 20 as necessary, and stores it in the data memory 33.

  For example, when the monitoring cooperation process 34a for the other control device 21 is executed by the control device 20, the I / O data d2 on the data memory 32 acquired by accessing the shared memory 22 can be used. The control device 21 can also use the I / O data d1 on the data memory 33 when the monitoring cooperation process 34a for the other control device 20 is executed.

  As described above, in the control system 19 according to the present embodiment, each of the control devices 20 and 21 can be accessed at high speed with the dedicated input / output devices 25 and 27, and yet another control device. Can efficiently acquire I / O data.

  Further, the control can be executed in cooperation while monitoring the state of input / output managed by another control device, whereby the reliability of the control operation of each control device 20, 21 in the control system 19 can be improved.

  Further, in the control system 19 according to the present embodiment, the independence of the control devices 20 and 21 can be ensured. Therefore, even if one control device fails, the other control device can continue control, and the operating rate of the control system 19 can be improved.

  In this embodiment, the case where there are two control devices has been described as an example, but the present invention can be similarly applied even when there are three or more control devices.

(Fourth embodiment)
In the present embodiment, a control system that improves the efficiency of a control operation that is executed while switching a plurality of control devices that access an input / output device will be described.

  FIG. 7 is a block diagram showing the configuration of the control system according to the present embodiment.

  In this control system 35, a regular control device 36 and a standby control device 37 are connected to an I / O bus 39 via a switching circuit 38, and the I / O bus 39 is further shared with an input / output device 40. A memory 41 is connected.

  The regular control device 36 executes the control process while transferring the I / O data between the data memory 42 provided therein and the I / O memory 43 of the input / output device 40.

  In addition, the regular control device 36 appropriately transmits control data used for the control process such as data (intermediate value of control) obtained during the control process as needed during the execution of the control process. To remember.

  The standby control device 37 receives the control data on the shared memory 41 and stores it in its own data memory 44 when the normal control device 36 fails, and uses this control data to perform control processing. Continue.

  The switching circuit 38 arbitrates the bus right of the I / O bus 39 when there is a normal access from the control devices 36 and 37 to the input / output device 40 and the shared memory 41, and between the control devices 36 and 37. Thus, the I / O bus 39 is used exclusively.

  In the control system 35, a plurality of control devices 36 and 37 can access the input / output device 40 and the shared memory 41, and can receive control data of other control devices from each other via the shared memory 41.

  FIG. 8 is a block diagram showing a state of data transfer executed by the control system 35 according to the present embodiment.

  While the switching circuit 38 gives the bus right to the control device 36, the regular control device 36 transfers I / O data between the data memory 42 and the I / O memory 43, and transfers the control data. Store in the shared memory 41.

  The standby control device 37 is the same as the control device 36, and transfers I / O data between the data memory 44 and the I / O memory 43 while the bus right is given by the switching circuit 38. Further, the control data is stored in the shared memory 41.

  In this control system 35, the control device 36 operates as a normal system and the control device 37 operates as a standby system, but the control device 36 sequentially stores control data in the shared memory 41.

  When the normal control device 36 breaks down, the standby control device 37 immediately takes over the control process executed by the normal control device 36 using the control data on the shared memory 41.

  As described above, in the control system 35 according to the present embodiment, since the latest control data of the control devices 36 and 37 is stored in the shared memory 41, the inheritance of processing from the normal system to the standby system is performed. Can be made more efficient.

  In addition, an operation (tracking) for transferring the control data between the plurality of control devices 36 and 37 and updating the contents of the control data held by both of the control devices 36 and 3 is not necessary. Time, tracking circuits, etc. can be omitted.

  In the present embodiment, the case where the control device is used as a regular system and a standby system has been described. However, the present invention is not limited to this mode.

  For example, a function of causing the control devices 36 and 37 to execute the same control program and synchronizing the programs with a flag stored in the shared memory 41 may be included in the control program. Thereby, the control apparatuses 36 and 37 can be executed in parallel.

  Further, when the control devices 36 and 37 are executed in parallel as described above, the I / O data output from the control devices 36 and 37 to the input / output device 40 is temporarily stored in the shared memory 41. Any one of them may compare the I / O data on the shared memory 41 and output the I / O data to the input / output device 40 only when they match.

  As a result, appropriate I / O data can be output to the input / output device 40. In this case, a control device that performs the comparison and output may be added to the control system 35.

  Further, in the present embodiment, the case where there are two control devices has been described as an example, but the present invention can be similarly applied even when there are three or more control devices.

(Fifth embodiment)
In the present embodiment, a control system that collectively executes data transfer between a shared memory and an input / output device accessed from at least one control device will be described.

  FIG. 9 is a block diagram showing the configuration of the control system according to the present embodiment.

  In this control system 45, control devices 46 and 47 are connected to an input / output device 51 via a shared memory 48, a data transfer circuit 49, and an I / O bus 50.

  The control devices 46 and 47 and the input / output device 51 include data memories 52 and 53 and an I / O memory 54, respectively.

  The data transfer circuit 49 is a circuit that collectively transfers data between the shared memory 48 and the I / O memory 54 based on designation from a plurality of control devices 46 and 47.

  Specifically, the data transfer circuit 49 includes an input function 49 a for storing the I / O data on the I / O memory 54 in the shared memory 48 according to the designation from the control devices 46 and 47, and the control devices 46 and 47. The output function 49b for storing the I / O data on the shared memory 48 in the I / O memory 54 in accordance with the designation from is included.

  For example, a transmission area and a reception area are provided on the shared memory 48, and one of the plurality of control devices 46 and 47 stores I / O data in the transmission area, and the I / O data is stored in the data transfer circuit 49. When an address or the like of the O memory 54 is designated, the data transfer circuit 49 stores the I / O data at the designated address of the I / O memory 54.

  On the other hand, for example, when any of the plurality of control devices 46 and 47 designates the address of the I / O memory 54 or the like to the data transfer circuit 49, the data transfer device 49 stores the address in the designated I / O memory 54. The read I / O data is read out and stored in the reception area of the shared memory 48.

  As a result, the control devices 46 and 47 can access the input / output device 51 only by accessing the shared memory 48.

  FIG. 10 is a block diagram showing a state of data transfer executed by the control system 45 according to the present embodiment.

  In this control system 45, I / O data transmitted from the control devices 46 and 47 to the input / output device 51 is stored in the shared memory 48, and the address of the shared memory 48, the address of the I / O memory 54, and the number of data are stored in the data. It designates to the transfer circuit 49.

  The data transfer circuit 49 stores the I / O data on the shared memory 48 in the I / O memory 54 according to the specified content.

  Further, the data transfer circuit 49 reads the I / O data stored at the address of the I / O memory 54 designated by the control devices 46 and 47, and the address of the shared memory 48 designated by the control devices 46 and 47. To remember.

  When the I / O data is stored at the address of the designated shared memory 48, the control devices 46 and 47 read the I / O data.

  By repeating the above operation, the same operation as that of normal access can be executed. Further, in the control devices 46 and 47 of the control system 45, the same program may be executed in parallel, or different programs may be executed in parallel.

  As described above, in the control system 45 according to the present embodiment, the I / O data is transferred between the control devices 46 and 47 and the input / output device 51 via the shared memory 48. Change in control operation when increasing or decreasing the number can be reduced. Therefore, it is possible to easily cope with fluctuations in the number of control devices.

  Also, by causing a plurality of control devices to execute different programs, parallel processing of the programs is possible, and the execution speed can be improved.

  In addition, the same program is stored in a plurality of control devices, and usually only one control device is operated as a regular system, and when this one control device fails, the processing is backed up by another control device in the standby system. Thus, the reliability of the control system 45 can be easily improved. In this case, the standby control device also executes the program in parallel and stores the result in the shared memory. Then, when the normal control device fails, the backup processing can be started at an early stage by changing the addressing of the data output from the shared memory 48 to the I / O memory 54 to the data transfer circuit 49. .

  In this embodiment, the case where there are two control devices has been described as an example. However, the control system 45 may have one or more control devices.

  In the present embodiment, the control devices 46 and 47 output the designation related to access to the data transfer circuit 49. For example, the control devices 46 and 47 store the designation related to access in the shared memory 48 and transfer the data. The circuit 49 may read the designation on the shared memory 48.

  In each of the above embodiments, the case where the control device accesses the input / output device is described as an example. For example, instead of the input / output device, the control device, the computer, the database, the communication device, or the like is the access destination. The same applies to the above.

The block diagram which shows the structure of the control system which concerns on the 1st Embodiment of this invention. The block diagram which shows the state of the data transfer which the control system 10 concerning the embodiment performs. The block diagram which shows the state of the data transfer by the interruption signal of the control system which concerns on the embodiment. The block diagram which shows the state of the data transfer by the simulation operation | movement in the 2nd Embodiment of this invention. The block diagram which shows the structure of the control system which concerns on the 3rd Embodiment of this invention. The block diagram which shows the state of the data transfer which the control system which concerns on the same embodiment performs. The block diagram which shows the structure of the control system which concerns on the 4th Embodiment of this invention. The block diagram which shows the state of the data transfer which the control system which concerns on the same embodiment performs. The block diagram which shows the structure of the control system which concerns on the 5th Embodiment of this invention. The block diagram which shows the state of the data transfer which the control system which concerns on the same embodiment performs. The block diagram which shows the structure of the conventional control system in which a some control apparatus shares an input / output device. The block diagram which shows the state of the data transfer in the conventional control system.

Explanation of symbols

  1, 10, 19, 35, 45 ... control system, 2, 3, 11, 12, 20, 21, 36, 37, 46, 47 ... control device, 4, 24, 26, 39, 50 ... I / O bus 5, 17, 25, 27, 40, 51 ... I / O device, 6 ... control target, 7, 8, 14, 15, 32, 33, 42, 44, 52, 53 ... data memory, 9, 18, 29 , 31, 43, 54 ... I / O memory, 13, 22, 41, 48 ... shared memory, 38 ... switching circuit, 49 ... data transfer circuit

Claims (4)

In a control system with input / output devices,
Shared storage means for storing data;
A regular control device that stores control data used in control processing based on data received from the input / output device in the shared storage means;
A standby control device that reads control data stored in the shared storage means and executes control processing when the normal control device fails; and
A control system comprising switching means for managing access to the input / output device by the regular control device and the standby control device so as not to overlap each other. The control system according to claim 1,
The regular control device executes the first control program,
The standby control device executes a second control program that realizes the same control processing as the first control program and operates in parallel with the first control program. In a control system with input / output devices,
Shared storage means for storing transmission data transmitted to the input / output device and reception data received from the input / output device;
A plurality of control devices for reading received data stored in the shared storage means and storing transmission data in the shared storage means;
A control system comprising data transfer means for transferring data between the input / output device and the shared storage means. The control system according to claim 3, wherein
The data transfer means includes
Means for transmitting data to be transmitted to the input / output device stored in the shared storage means to the input / output device at predetermined intervals or at arbitrary timing;
A control system comprising: means for receiving data to be received by any one of the plurality of control devices from the input / output device at predetermined intervals or at arbitrary timings and storing the data in the shared storage unit .

Images