JP3956206B2 - Engineering equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engineering apparatus that defines and downloads various functions of field devices that constitute a fieldbus system.
[0002]
[Prior art]
In recent years, plant control using a fieldbus has been performed. In plant control using a field bus, a field bus is laid in the plant, a field device is connected to the field bus, and the field device performs control of the plant while communicating with each other. In addition, the field device controls the plant while communicating with the distributed control system in the upper hierarchy. In plant control using a fieldbus, it is possible to provide intelligence to field devices arranged in the field and to distribute control functions suitable for the distributed control system to the field.
[0003]
Various functions of the field devices constituting the field bus system are defined by an engineering device and converted into a database, downloaded to the field devices, and predetermined control is executed. When a fieldbus system is introduced in a distributed control system, an engineering device is often connected to a control bus in parallel with an operation monitoring station that is a host device of the distributed control system.
[0004]
FIG. 3 is a functional block diagram showing a system configuration when a fieldbus system is introduced in the distributed control system. 1 is an upper control bus, 2 is an operation monitoring station which is an upper device connected to the control bus 1, and 3 is also connected to the control bus 1 to communicate with the operation monitoring station 2 and to control a process. It is.
[0005]
Reference numeral 4 denotes a lower I / O bus connected to the field control station 3, and a dotted block 5 denotes a field bus system, which communicates with the field control station 3 via the I / O bus 4.
[0006]
In the field bus system 5, reference numeral 6 denotes a field bus, and 71, 72, 73,... 7 n are a plurality of field devices connected to the field bus 6. An interface device 8 connects the field bus 6 and the I / O bus 4.
[0007]
Reference numeral 9 denotes an engineering device connected to the upper control bus 1, which defines various functions of the fieldbus system 5, creates a database, and downloads it to field devices of the fieldbus system 5 by communication via the field control station 3. .
[0008]
The engineering device 9 can be realized by a general-purpose PC means in which engineering software is installed.
[0009]
The unit of signal processing in the field device is a function block, and a predetermined control process is executed by combining one or a plurality of function blocks. The generation of the function block execution schedule is executed in the generation means executed on the FB editor of the engineering apparatus.
[0010]
The function of the generation means will be described with reference to FIG. The block 10 is a generation means executed on the FB editor (function block editor) of the engineering apparatus 9, 101 is a VCR (Virtual Communication Relationship) generator for defining a communication path, 102 is a link object generator, and 103 is a segment. LAS (Link Active Schedule) schedule generation unit that defines traffic management of the network, 104 is a function block schedule generation unit (FB schedule generation unit) that is the subject of the present invention, 105 is a scheduling unit, and 106 is a host file generation unit is there.
[0011]
The LAS schedule generation unit 103 and the FB schedule generation unit 104 determine resources to be used, and specific setting data (communication and block execution start time and the like) are determined by the scheduling unit 105. The defined engineering information is registered in the engineering database 107 and downloaded to the fieldbus system 5.
[0012]
An object that defines when and when a function block to be used is executed is an “execution scheduling object”. This object is implemented as a resource in the field device, and the determined specific data is set in the device by downloading.
[0013]
The specific data is determined by the generation and scheduling means 105 of the FB schedule generation unit 104. The generation determines the object to be used, and the scheduling means determines the execution start time. An object of the present invention is an algorithm for determining a use object in generation.
[0014]
One or more execution scheduling objects are defined for a function block. FIG. 5 is a flowchart showing a conventional execution scheduling object generation algorithm.
[0015]
First, in step S1, the control cycle (execution cycle) of the function block application (FBAP) is acquired, and in step S2, the macro cycle of the segment is acquired.
[0016]
Here, the control cycle is a time interval required for one cycle of a control loop (configured using a plurality of function blocks). The control cycle may vary depending on the control loop to be configured. A macro cycle is the least common multiple of each control period. A macro cycle is a value common to a segment (one fieldbus) and is a value set for each field device.
[0017]
In step S3, the ratio between the control cycle of the macro cycle and the function block is taken to determine how many times the control is executed within the macro cycle (number of executions). In step S5, the function block execution scheduling object for the number of executions is obtained. Generate.
[0018]
If the control cycles of function blocks belonging to the same device are different, it is necessary to define the function block execution schedule for the number of executions by the ratio of the segment macro cycle and each control cycle, and the resources implemented in the device (Memory area) is consumed for the defined number.
[0019]
For example, if the macro cycle is 1000 msec and the control cycle of a certain function block is 500 msec, 1000/500 = 2 execution schedule resources are required for the function block.
[0020]
[Problems to be solved by the invention]
If function blocks belonging to the same device operate in the same control cycle, it is only necessary to consume one execution schedule resource for each function block. In this case, the macro cycle set in this device is not a segment macro cycle value but a control cycle in which the function block operates.
[0021]
However, in the conventional algorithm for defining execution schedule resources, even if the control periods are all the same, if the control period is different from the macro cycle value, the execution schedule resources for “macro cycle / control period” are wasted. .
[0022]
If a device that does not have enough function block execution schedule resources is used, a “resource shortage” may occur during generation based on the FBAP configuration (control loop configuration). Therefore, in the conventional engineering, there may be a case where a device on which only a minimum necessary function block execution schedule resource is mounted cannot be handled.
[0023]
The purpose of the present invention is to optimize the use of function block execution schedule resources that enable engineering of field devices that could not be handled or projects (segment engineering units) in which “resource shortages” occurred in the prior art. The realization of the realized engineering equipment.
[0024]
[Means for Solving the Problems]
(1) In an engineering apparatus having a generation means for generating an execution scheduling object for a plurality of function blocks mounted on a field device constituting a fieldbus system,
The generation means investigates the control cycle of the function block belonging to the same device, and when all the control cycles are the same, the macro cycle value of the segment set in the device is set as the control cycle of the function block, and the function block An engineering device that executes an optimization process for generating one execution scheduling object for each.
[0025]
(2) The generation means refers to the environment setting of the function block belonging to the same device, and executes the control cycle when the optimization process is executed, and does not execute the optimization process. The engineering apparatus according to claim 1, wherein a macro cycle of the segment is acquired, a macro cycle / control period is calculated, and an execution scheduling object corresponding to the number of execution times in the macro cycle is generated for the function block.
[0026]
(3) The generation means investigates the control cycle of the function block belonging to the same device, and if the control cycle is different , calculates the macro cycle / control cycle, and within the macro cycle for the function block The engineering device according to claim 1, wherein execution scheduling objects corresponding to the number of execution times are generated.
[0027]
(4) The engineering device according to any one of claims 1 to 3, wherein the engineering device of the fieldbus system is realized by a general-purpose personal computer connected to a control bus of a distributed control system.
[0028]
(5) The engineering device according to any one of claims 1 to 3, wherein the engineering device of the fieldbus system is realized by a fieldbus builder connected to a control bus of a distributed control system.
[0029]
(6) The engineering device according to claim 5, wherein switching is performed as to whether or not to execute the optimization processing according to designation of an environment setting function of the fieldbus builder.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing an example of an engineering apparatus to which the present invention is applied. The same elements as those described in the conventional apparatus of FIG.
[0031]
The characteristic part of the present invention is the configuration of the FB schedule generation unit 108 in the generation means 10. The functions of the FB schedule generation unit 108 of the present invention include an environment setting reference unit 108a, an FB schedule generation algorithm 108b, and an optimization algorithm 108c.
[0032]
The FB schedule generation unit 108 has two algorithms, the FB schedule generation algorithm and the optimization algorithm as described above.
First, in the FB schedule generation algorithm, the macro cycle is common to the segments and is set for all devices. As for the execution schedule of the function block belonging to each device, the number to be generated is determined by the ratio between the control cycle of the function block and the macro cycle. This is the same as the conventional generation algorithm.
[0033]
Next, in the optimization algorithm, the control cycle of the function block belonging to the same device is investigated, and when all are executed in the same control cycle, the macro cycle value set in the device is set as the control cycle of the function block, There is one execution scheduling object for each function block. This is a new algorithm introduced in the present invention.
[0034]
When function blocks in the same device have different control periods, an execution execution scheduling object is determined for each function block using a conventional generation algorithm.
[0035]
Switching between adopting the new algorithm of the present invention or the conventional algorithm as the FB schedule generation algorithm depends on the application. Depending on the application, which algorithm is used can be selected by the environment setting function. The algorithm selection can be specified in segment units.
[0036]
Prior to the execution schedule generation, the environment setting reference unit 108a checks the environment setting function of the FB application, and determines whether or not to execute the optimization processing according to the algorithm of the present invention.
[0037]
When “resource shortage” occurs as a result of generation by the conventional algorithm, the error can be solved by checking “optimize”. Engineering according to the application can be easily performed by switching the environment setting.
[0038]
FIG. 2 is a flowchart showing an operation procedure of FB schedule generation by the generation means of the present invention. First, in step S1, the environment setting is referred to, and in step S2, which algorithm (with / without optimization) is to be adopted is determined.
[0039]
When the optimization process is not performed, a conventional algorithm is employed. First, in step S3, the ratio between the control cycle of the macro cycle and the function block is taken to determine how many times the control is executed in the macro cycle (number of executions), and in step S4, execution scheduling objects for the number of executions are generated. To do.
[0040]
When the optimization process is performed based on the determination in step S2, a control cycle is acquired according to which FBAP the function block belongs to in step S5, and a macro cycle of the segment is acquired in step S6.
[0041]
Further, in step S8, control cycles of all function blocks belonging to the same device are extracted, and in step S9, it is determined whether or not all control blocks have the same control cycle. If they are the same, in step S10, the control cycle is set as a macro cycle, and one execution scheduling object common to each function block is generated.
[0042]
If the control period is different in the determination in step S9, the process is performed by the conventional algorithm in steps S3 and S4, and the number to be generated is calculated by the ratio between the respective control period and the macro cycle of the segment, and the execution scheduling for that number is performed. Create an object.
[0043]
In this case, when the number of generated execution scheduling objects exceeds the number of resources set in the field device, a generation error occurs.
[0044]
The number of function block execution schedule resources of the field device is described as a device-specific setting value in the capability file (CP). For example, it is assumed that three function blocks are implemented in a certain device, and three function block execution schedule resources are also implemented.
[0045]
A control loop is created by using two three function blocks, and the control cycle is 500 msec in all cases. If the macro cycle of the segment is 1000 msec at this time, one execution scheduling object is generated in the case of “optimizing”. Since the number of resources is 3, no engineering error occurs.
[0046]
In the case of “not optimizing”, a total of four execution scheduling objects are generated. However, since there are three function block execution schedule resources in total, an engineering error that the number of resources has been exceeded occurs when the fourth execution scheduling object is generated.
[0047]
As described above, according to the present invention, it is possible to avoid the duplication of function block execution scheduling objects having the same specifications, thereby facilitating the engineering of field devices having a small number of resources, and improving the expandability of applications with a small number of resources. Can be made.
[0048]
In the embodiment described above, the engineering apparatus 9 has shown the example in which the general-purpose PC on which the engineering software is installed is connected to the control bus 1 of the distributed control system. However, the engineering apparatus 9 can be directly connected to the field bus 6. .
[0049]
Further, in a distributed control system system in which an engineering station (not shown) having a builder function for defining display, control program, parameters, etc. of the operation monitoring station 2 and the field control station 3 is connected to the control bus 1. It is also possible to give the function of the engineering device in the form of a fieldbus builder in the function of this engineering station.
[0050]
In this case, switching of the algorithm for generating the execution scheduling object can be designated by the environment setting function of the fieldbus builder.
[0051]
【The invention's effect】
As is clear from the above description, the following effects can be expected according to the present invention.
(1) The resource shortage of the function block execution schedule resource can be solved.
(2) It is possible to engineer even a device that implements the minimum necessary function block execution schedule resources.
(3) Since the resource shortage of the function block execution schedule resource can be resolved, more variations of applications (device configuration and control loop configuration) can be provided.
(4) With the function block execution schedule generation algorithm switching mechanism, two different generation algorithms can be selected, and appropriate engineering according to the application to be constructed can be realized.
[Brief description of the drawings]
FIG. 1 is a functional block diagram illustrating functions of a generation means according to the present invention. FIG.
FIG. 2 is a flowchart showing an algorithm for generating a function block execution scheduling object according to the present invention.
FIG. 3 is a functional block diagram showing a system configuration when a fieldbus system is introduced in a distributed control system.
FIG. 4 is a functional block diagram illustrating functions of conventional generation means.
FIG. 5 is a flowchart showing a conventional algorithm for generating a function block execution scheduling object.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Control bus 2 Operation monitoring station 3 Field control station 4 I / O bus 5 Field bus system 6 Field bus 71,72,73, ... Field apparatus 8 Interface apparatus 9 Engineering apparatus 10 Generation means 108 FB schedule generation part 108a Refer to environmental setting Unit 108b FB schedule generation algorithm 108c optimization algorithm

Claims (6)

In an engineering device having a generation means for generating an execution scheduling object for a plurality of function blocks implemented in a field device constituting a fieldbus system,
The generation means investigates the control cycle of the function block belonging to the same device, and when all the control cycles are the same, the macro cycle value of the segment set in the device is set as the control cycle of the function block, and the function block An engineering device that executes an optimization process for generating one execution scheduling object for each. The generation means refers to the environment setting of the function block belonging to the same device, performs the control cycle when performing the optimization process, and performs the segment when the optimization process is not performed. The engineering apparatus according to claim 1, wherein a macro cycle / control cycle is calculated and an execution scheduling object corresponding to the number of execution times in the macro cycle is generated for the function block. The generation means investigates the control cycle of the function block belonging to the same device, and when the control cycle is different , calculates the macro cycle / control cycle, and executes the number of executions in the macro cycle for the function block. The engineering apparatus according to claim 1, wherein an execution scheduling object for minutes is generated.   The engineering apparatus according to any one of claims 1 to 3, wherein the engineering apparatus of the fieldbus system is realized by a general-purpose personal computer connected to a control bus of a distributed control system.   The engineering apparatus according to any one of claims 1 to 3, wherein the engineering apparatus of the field bus system is realized by a field bus builder connected to a control bus of a distributed control system.   The engineering apparatus according to claim 5, wherein switching of whether or not to execute the optimization processing is executed according to designation of an environment setting function of the fieldbus builder.

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