JP3550292B2 - Controller system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a controller system for monitoring and controlling various devices in a large-scale plant such as an electric power plant, and particularly to the occurrence of abnormalities among a plurality of programmable logic controllers (hereinafter abbreviated as PLCs) on the site. The present invention relates to a controller system in which control can be continued by a single backup controller in place of a modified PLC or a PLC that needs to be modified.
[0002]
[Prior art]
Recently, in a large-scale plant such as a power plant, for example, a controller system in which monitoring and control of various devices of a plant on the site side are performed using a plurality of controllers from a central side has been often used.
[0003]
A conventional controller system of this kind is provided at a central side and provides a human-machine system for giving operation instructions for operating various devices to be controlled on the site side, and a plurality of control objects (various devices) for each. A plurality of PLCs correspondingly provided on the site side and individually controlling the control target according to a control program based on an operation instruction from the human machine system, and connecting the human machine system and the plurality of PLCs to each other, And a transmission line for performing the transmission of the data. The central human machine system monitors and controls a plurality of control targets via a plurality of PLCs.
[0004]
However, in such a conventional controller system, when an abnormality of the PLC (an abnormality of the main body of the PLC or a transmission error of a connection cable connecting between the PLC and the transmission line) occurs on the site side, the central side of the controller system. It becomes impossible to monitor and control a plurality of control targets (various devices) on the site side from the human machine system.
[0005]
As a result, in many cases, maintenance personnel actually go to the site and operate alone at the site.
On the other hand, a method of backing up a controlled object that requires continuation of operation even if a PLC is abnormal due to the characteristics of a plant, for example, by hardware (such as a relay circuit) or by duplicating a plurality of PLCs Is adopted.
However, the latter method, in particular, requires two identical controllers, which is not preferable because of problems such as cost and location.
[0006]
[Problems to be solved by the invention]
As described above, in the conventional controller system, when any abnormality occurs in the PLC on the site side, the problem is that monitoring and control of the control target (various devices) on the site side from the central side becomes practically impossible. was there.
[0007]
In addition, in order to enable monitoring and control of a control target on the site side from the central side, it is necessary to duplicate a plurality of PLCs, which is problematic in terms of cost and location.
An object of the present invention is to replace a function of the PLC with only one backup controller for occurrence of some abnormality of the PLC on the site side, maintain the integrity of the entire system, and construct a robust system. It is to provide a controller system capable of performing the above.
[0008]
Further, another object of the present invention is to replace the PLC function with only one backup controller in response to the need to modify the PLC on the site side, to maintain the integrity of the entire system, and to provide robustness. It is to provide a controller system capable of constructing a system.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a human-machine system provided at the central side and providing operation instructions for operating a plurality of controlled objects on the site side, and provided on the site side corresponding to each of the plurality of controlled objects A plurality of programmable logic controllers that individually control a control target via an I / O unit in accordance with a control program based on an operation instruction from a human-machine system, and a human-machine system and a plurality of programmable logic controllers. And a transmission line for transmitting information, and a controller system for monitoring and controlling a plurality of controlled objects from a human machine system via a plurality of programmable logic controllers,
According to the first aspect of the present invention, there is provided a backup controller, and a private bus for connecting the backup controller and the I / O units of the plurality of programmable logic controllers to each other and transmitting data,
The backup controller stores control program holding means for holding the same control program as the latest control program of each of the plurality of programmable logic controllers, and privately stores the latest I / O data of the plurality of programmable logic controllers. Data holding means for capturing and holding via a bus, and abnormality occurrence detecting means for monitoring the states of a plurality of programmable logic controllers via a transmission line and detecting whether or not an abnormality has occurred in all of the programmable logic controllers When the occurrence of abnormality is detected by the abnormality detection means, the programmable logic controller in which the abnormality has occurred is switched to the control via the private bus, and the programmable logic controller in which the abnormality has occurred is switched. It is assumed that a control means to continue the alternate to control the.
[0010]
Therefore, in the controller system according to the first aspect of the present invention, if any abnormality occurs in the programmable logic controller on the site side, the abnormality is detected by the backup controller, and the function of the programmable logic controller is reset. By substituting, the monitoring and control of the control object on the site side can be continuously performed from the central side, so that the integrity of the entire system can be maintained.
[0011]
Furthermore, even if there are a plurality of programmable logic controllers on the site side, substituting these functions with only one backup controller eliminates the need for a sub-controller for each programmable logic controller. A robust system can be constructed using only the backup controller.
[0012]
According to a second aspect of the present invention, in the controller system according to the first aspect of the present invention, the backup controller transmits a state of a plurality of programmable logic controllers instead of the abnormality occurrence detecting means and the control means. A modification detection means that monitors via a line and detects whether or not any modification such as a control program change has been made to all of the programmable logic controllers, and the necessity of the modification is detected when the modification detection means detects the modification. Control means for switching to the control via the private bus for the generated programmable logic controller and continuing the control in place of the programmable logic controller requiring the modification.
[0013]
Therefore, in the controller system according to the second aspect of the present invention, when the programmable logic controller is modified (control program change or the like) on the site, the backup controller detects that the modification is performed, By substituting the function of the programmable logic controller, the remodeling work of the programmable logic controller can be performed while the operation of the control target on the site side is continued.
[0014]
Furthermore, even if there are a plurality of programmable logic controllers on the site side, substituting these functions with only one backup controller eliminates the need for a sub-controller for each programmable logic controller. A robust system can be constructed using only the backup controller.
[0015]
On the other hand, in the invention of claim 3, the backup controller has all of the abnormality occurrence detection means, the modification detection means, and each control means in the controller system of the inventions of claim 1 and claim 2. I have.
[0016]
Therefore, in the controller system according to the third aspect of the invention, the same operation as in the case of the controller systems according to the first and second aspects of the invention can be achieved.
[0017]
As described above, it is possible to respond to the occurrence of any abnormalities in the programmable logic controller at the site without causing the above-mentioned cost and location problems, and maintain the integrity of the entire system. It is possible to construct a robust system.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic block diagram showing an example of a controller system according to the present embodiment.
[0019]
In FIG. 1, a human machine system 1 provided on a central side, a backup controller 2, and a plurality (N) of local PLCs 31 provided on the site corresponding to a plurality of control targets (various devices) of a plant, respectively. , 32, ..., 3N are connected to each other by a transmission line 4 for transmitting information.
[0020]
Each of the local PLCs 31, 32,..., 3N comprises a control unit 31a, 32a,..., 3Na and an I / O unit 31b, 32b,. , ..., 3N I / O units 31b, 32b, ..., 3Nb are connected to each other by a private bus 5 for data transmission.
[0021]
Further, the I / O units 31b, 32b,..., 3Nb of the local PLCs 31, 32,..., 3N include a controller, a digital input (DI), an analog input (AI), a digital output (DO), and an analog output ( AO), and are connected to relay contacts 61, 62,..., 6N that operate control targets (various devices) of the corresponding on-site plant by connection cables.
[0022]
Furthermore, backup uninterruptible power supplies 71, 72,..., 7N are connected to the local PLCs 31, 32,.
Each of the local PLCs 31, 32,..., 3N is operated when the control program stored in the control unit 32a needs to be modified (change of the control program, etc.). It has an operation switch.
[0023]
When the local PLC is remodeled, the operation signal of the operation switch used for remodeling the local PLC is uploaded to the backup controller 2 through the transmission line 4.
[0024]
On the other hand, the human machine system 1 is for an operator to give an operation instruction for operating a control target (various devices) of a plant on the site side.
The control units 31a, 32a, ..., 3Na of the local PLCs 31, 32, ..., 3N each have a memory in which a control program is stored, and based on an operation instruction from the human machine system 1, According to its own control program, the control targets are individually controlled via the I / O units 31b, 32b,..., 3Nb.
[0025]
Thereby, monitoring and control of a plurality of control targets are performed from the human machine system 1 via the plurality of local PLCs 31, 32,..., 3N. On the other hand, the backup controller 2 includes a control unit 2a and two memories 2b and 2c.
[0026]
The memory 2b holds the same control programs as the latest control programs of the control units 31a, 32a,..., 3Na of the local PLCs 31, 32,. ).
[0027]
.., 3Nb of the local PLCs 31, 32,..., 3N via the private bus 5. Data holding means).
[0028]
Further, the control section 2a has a memory in which a backup control program is stored.
As a control program for this backup,
, 3N through the transmission line 4 to detect the status of each of the local PLCs 31, 32,..., 3N, and to detect whether or not any of the local PLCs 31, 32,.
, 3N via the transmission line 4 to detect the status of each of the local PLCs 31, 32,..., 3N, and to detect whether or not any of the local PLCs 31, 32,. When,
When the occurrence of abnormality is detected by the abnormality detection function, or when the modification is detected by the modification detection function, the private bus 5 is connected to the local PLC in which the abnormality has occurred or the need for modification has occurred. And a control function for continuing the control in place of the local PLC in which an abnormality has occurred or in need of remodeling.
[0029]
Next, the operation of the controller system of the present embodiment configured as described above will be described.
(A) When each local PLC 31, 32, ..., 3N is sound
In FIG. 1, when no abnormality has occurred in each of the local PLCs 31, 32,..., 3N on the site side, an operation instruction given by the operator from the human machine system 1 is transmitted through the transmission line 4 to the local PLCs 31, 32. ,..., 3N are taken into the control units 31a, 32a,.
[0030]
Thus, the control units 31a, 32a, ..., 3Na of the local PLCs 31, 32, ..., 3N, based on the operation instruction from the human machine system 1, according to their own control programs, the I / O units 31b, 32b, ..., 3N. Via the 3Nb, the control targets (various devices) of the corresponding on-site plants are individually controlled by the relay contacts 61, 62,..., 6N.
[0031]
On the other hand, in the backup controller 2, the latest I / O data of the I / O units 31b, 32b,..., 3Nb of the local PLCs 31, 32,. It is held in the memory 2c.
[0032]
(B) When a local PLC error occurs
Next, some kind of abnormality (an abnormality in the main body (control unit 32a) of the PLC 32 or an abnormality in the transmission of a connection cable connecting the PLC 32 and the transmission line 4) actually occurs in a certain local PLC (for example, the local PLC 32). In this case, the occurrence of an abnormality in the local PLC 32 is detected through the transmission line 4 by the abnormality occurrence detection function of the backup controller 2.
[0033]
Then, in the backup controller 2, the control function switches the local PLC 32 in which the abnormality has occurred to the control via the private bus 5, and continues the control in place of the local PLC 32 in which the abnormality has occurred.
[0034]
That is, in this case, the continuation of the substitute control by the backup controller 2 is performed based on the latest I / O data of the I / O unit 32b of the local PLC 32 stored in the memory 2c of the backup controller 2 and stored in the memory 2b. This is performed by controlling the control target via the I / O unit 32b of the local PLC 32 according to the same control program as the latest control program of the control unit 32a of the local PLC 32.
[0035]
On the other hand, in the above case, if the backup controller 2 detects that an abnormality has occurred in the local PLC 32 during transmission of data through the private bus 5, the data may be incomplete.
[0036]
Therefore, in such a case, the local PLC 32 is backed up by the uninterruptible power supply 72 until it is updated to the latest I / O data. Then, when the latest I / O data is held in the memory 2c of the backup controller 2, the local PLC 32 in which the abnormality has occurred is switched to the control via the private bus 5, and replaced with the local PLC 32 in which the abnormality has occurred. Control will continue.
[0037]
In this way, when any abnormality occurs in the local PLC 32 on the site side, the backup controller detects the abnormality and substitutes the function of the local PLC 32, thereby monitoring and controlling the control target on the site side from the central side. Can be performed successively, so that the integrity of the entire system can be maintained.
[0038]
FIG. 2 is a time chart showing an example of a state of data exchange between the local PLCs 31, 32,..., 3N and the backup controller 2 when an abnormality occurs in the local PLC 32.
[0039]
In FIG. 2, A indicates data of the local PLC 31, B indicates data of the local PLC 32, N indicates data of the local PLC 3N, and BC indicates data of the backup controller 2.
[0040]
(C) When the local PLC is modified (change of control program, etc.)
When a certain local PLC (for example, the local PLC 32) needs to modify the control program stored in the control unit 32a (change the control program, etc.), the modification of the local PLC 32 is performed. It is detected through the transmission line 4 by the modification detection function of the backup controller 2 based on an operation signal from a modification operation switch (not shown) of the local PLC 32.
[0041]
Then, in the backup controller 2, the control function switches the local PLC 32 that needs to be remodeled to the control via the private bus 5, and continues the control in place of the local PLC 32 that needs to be remodeled.
[0042]
That is, in this case, the continuation of the substitute control by the backup controller 2 is performed based on the latest I / O data of the I / O unit 32b of the local PLC 32 stored in the memory 2c of the backup controller 2 and stored in the memory 2b. This is performed by controlling the control target via the I / O unit 32b of the local PLC 32 according to the same control program as the latest control program before the modification of the control unit 32a of the local PLC 32.
[0043]
As a result, when the local PLC 32 is modified (control program change or the like) on the site side, it takes time and effort to stop the operation of the control target on the site side or perform the modification in response to the power outage time. The backup controller 2 detects the modification of the local PLC 32 and substitutes the function of the local PLC 32, so that the modification work can be performed while the operation of the control target on the site side is continued.
[0044]
As described above, the controller system of the present embodiment includes the backup controller 2 and connects the backup controller 2 to the I / O units 31b, 32b,..., 3Nb of the local PLCs 31, 32,. , Connected to each other by a private bus 5 for transmitting data,
Further, the backup controller 2 holds the same control programs as the latest control programs of the control units 31a, 32a,..., 3Na of the local PLCs 31, 32,. , 3N I / O units 31b, 32b,..., 3Nb are fetched and held via the private bus 5 and all the local PLCs 31, 32,. , And the presence or absence of a modification such as a change in the control program is detected for all of the local PLCs 31, 32,..., 3N, and when an abnormal occurrence of the local PLC is detected, or a modification of the local PLC is detected. In this case, the local PLC that has this abnormality or needs Switched to control via Tobasu 5, abnormality has occurred, or in which modification required is to continue the alternate to control the local PLC produced.
[0045]
Therefore, the following various effects can be obtained.
(A) If any abnormality occurs in the local PLCs (31, 32,..., 3N) on the site side, the backup controller 2 detects the abnormality and substitutes the function of the local PLC for central control. Since the monitoring and control of the control target on the site side can be continuously performed from the side, it is possible to maintain the integrity of the entire system.
[0046]
(B) When the local PLC (31, 32,..., 3N) is modified (control program change, etc.) on the site, the operation of the control target on the site is stopped, or the modification corresponds to the power outage time. Although it takes time and effort, the function of the local PLC can be replaced by one backup controller 2, so that the remodeling work can be performed while the operation of the control target on the site side is continued.
[0047]
(C) Even if there are a plurality of (31, 32,..., 3N) local PLCs on the site side, by substituting their functions with only one backup controller 2, each local PLC (31, 32,. Since the sub-controller for 3N) is not required, a robust system can be constructed with only one backup controller 2.
[0048]
As described above, it is possible to respond to the occurrence of any abnormality in the local PLC (31, 32,..., 3N) on the site side without causing the above-described cost problem, location securing problem, and the like. As a result, it is possible to build a robust system.
[0049]
(Other embodiments)
(A) In the above-described embodiment, a case has been described in which one of the local PLCs 31, 32,..., 3N has any abnormality. However, the present invention is not limited to this. ,..., And 3N, or a case where any abnormality has occurred in all the local PLCs, it is possible to cope with the case as described above.
[0050]
That is, for example, when some abnormality occurs in two local PLCs (for example, the local PLCs 31 and 32) among the plurality of local PLCs 31, 32,..., 3N, the abnormality is generated by the control function of the backup controller 2. The local PLCs 31 and 32 are respectively switched to the control via the private bus 5, and the control is continued instead of the local PLCs 31 and 32 in which the abnormality has occurred.
[0051]
More specifically, the continuation of the substitute control by the backup controller 2 is based on the latest I / O data of the I / O units 31 b and 32 b of the local PLCs 31 and 32 held in the memory 2 c of the backup controller 2. Controlling the control target via the I / O units 31b and 32b of the local PLCs 31 and 32 according to the same control program as the latest control program of the control units 31a and 32a of the local PLCs 31 and 32 held in the 2b. It is performed by
[0052]
As described above, it is possible to obtain the same operation and effect as in the above-described embodiment.
(B) In the above-described embodiment, a case has been described in which it is necessary to modify one of the local PLCs 31, 32,... In the case where it is necessary to modify two or more local PLCs among the plurality of local PLCs 31, 32,... it can.
[0053]
That is, for example, when it becomes necessary to modify two local PLCs (for example, the local PLCs 31 and 32) among the plurality of local PLCs 31, 32,..., 3N, the modification is performed by the control function of the backup controller 2. The local PLCs 31 and 32 that need to be changed are switched to controls via the private bus 5, respectively, and the control is continued instead of the local PLCs 31 and 32 that need to be remodeled.
[0054]
More specifically, the continuation of the substitute control by the backup controller 2 is based on the latest I / O data of the I / O units 31 b and 32 b of the local PLCs 31 and 32 held in the memory 2 c of the backup controller 2. According to the same control program as the latest control program before the modification of the control units 31a and 32a of the local PLCs 31 and 32 held in the local PLCs 2b, the control targets are controlled via the I / O units 31b and 32b of the local PLCs 31 and 32, respectively. It is performed by controlling.
[0055]
As described above, it is possible to obtain the same operation and effect as in the above-described embodiment.
(C) In the above embodiment, the case where the backup controller 2 has all of the abnormality detection function, the modification detection function, and the control function has been described. However, the present invention is not limited thereto. It goes without saying that the control function may be a function having only one of the detection function and the modification detection function and a control function.
[0056]
(D) In the above embodiment, the case where backup uninterruptible power supplies 71, 72,..., 7N are connected to the local PLCs 31, 32,. is not.
[0057]
【The invention's effect】
As described above, according to the present invention, the function of the PLC is replaced with only one backup controller in response to occurrence of any abnormality in the PLC on the site side or in need of remodeling the PLC. Therefore, it is possible to provide a controller system that can maintain the integrity of the entire system and build a robust system.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram showing an embodiment of a controller system according to the present invention.
FIG. 2 is a time chart for explaining an operation in the controller system of the same embodiment.
[Explanation of symbols]
1. Human machine system
2. Backup controller,
2a ... control part,
2b ... memory,
2c ... memory,
31, 32, ..., 3N ... local PLC,
31a, 32a, ..., 3Na ... control part,
31b, 32b,..., 3Nb.
5. Private bus,
61, 62,..., 6N...
71, 72, ..., 7N ... uninterruptible power supply.

Claims (3)

A human-machine system that is provided on the center side and provides operation instructions for operating a plurality of control targets on the site side,
A plurality of programmable logics respectively provided on the site side corresponding to the plurality of controlled objects and individually controlling the controlled objects via an I / O unit according to a control program based on an operation instruction from the human machine system.・ Controller and
A transmission line for connecting the human machine system and the plurality of programmable logic controllers to each other and transmitting information,
In the controller system that performs monitoring control of the plurality of controlled objects from the human machine system via the plurality of programmable logic controllers,
A backup controller,
A private bus for connecting the backup controller and the I / O units of the plurality of programmable logic controllers to each other and performing data transmission;
The backup controller,
Control program holding means for holding the same control program as the latest control program of each of the plurality of programmable logic controllers,
Data holding means for receiving and holding the latest I / O data of the plurality of programmable logic controllers via the private bus;
Abnormality occurrence detection means for monitoring the states of the plurality of programmable logic controllers via the transmission line and detecting whether or not an abnormality has occurred for all of the programmable logic controllers;
When the occurrence of abnormality is detected by the abnormality occurrence detecting means, the programmable logic controller in which the abnormality has occurred is switched to the control via the private bus, and replaced with the programmable logic controller in which the abnormality has occurred. Control means for continuing control by
A controller system comprising: A human-machine system that is provided on the center side and provides operation instructions for operating a plurality of control targets on the site side,
A plurality of programmable logics respectively provided on the site side corresponding to the plurality of controlled objects and individually controlling the controlled objects via an I / O unit according to a control program based on an operation instruction from the human machine system.・ Controller and
A transmission line for connecting the human machine system and the plurality of programmable logic controllers to each other and transmitting information,
In the controller system that performs monitoring control of the plurality of controlled objects from the human machine system via the plurality of programmable logic controllers,
A backup controller,
A private bus for connecting the backup controller and the I / O units of the plurality of programmable logic controllers to each other and performing data transmission;
The backup controller,
Control program holding means for holding the same control program as the latest control program of each of the plurality of programmable logic controllers,
Data holding means for receiving and holding the latest I / O data of the plurality of programmable logic controllers via the private bus;
Modification detecting means for monitoring the states of the plurality of programmable logic controllers via the transmission line and detecting the presence or absence of modification such as a control program change for all of the programmable logic controllers,
When the alteration is detected by the alteration detecting means, the control is switched to the control via the private bus for the programmable logic controller requiring the alteration, and the programmable logic controller requiring the alteration is switched to the programmable logic controller. A control means for continuing control instead;
A controller system comprising: A human-machine system that is provided on the center side and provides operation instructions for operating a plurality of control targets on the site side,
A plurality of programmable logics respectively provided on the site side corresponding to the plurality of controlled objects and individually controlling the controlled objects via an I / O unit according to a control program based on an operation instruction from the human machine system.・ Controller and
A transmission line for connecting the human machine system and the plurality of programmable logic controllers to each other and transmitting information,
In the controller system that performs monitoring control of the plurality of controlled objects from the human machine system via the plurality of programmable logic controllers,
A backup controller,
A private bus for connecting the backup controller and the I / O units of the plurality of programmable logic controllers to each other and performing data transmission;
The backup controller,
Control program holding means for holding the same control program as the latest control program of each of the plurality of programmable logic controllers,
Data holding means for receiving and holding the latest I / O data of the plurality of programmable logic controllers via the private bus;
Abnormality occurrence detection means for monitoring the states of the plurality of programmable logic controllers via the transmission line and detecting whether or not an abnormality has occurred for all of the programmable logic controllers;
Modification detecting means for monitoring the states of the plurality of programmable logic controllers via the transmission line and detecting the presence or absence of modification such as a control program change for all of the programmable logic controllers,
When the occurrence of abnormality is detected by the abnormality occurrence detecting means, or when the modification is detected by the modification detecting means, the abnormality is generated or the programmable logic controller in which the modification is required Control means for switching to control via a private bus and continuing the control in place of the programmable logic controller in which the abnormality has occurred or in need of remodeling,
A controller system comprising:

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