JPH06161502A - Control arithmetic unit - Google Patents

Abstract

(57) [Summary] [Purpose] To enable initialization processing to prevent signal bumps without knowledge of the internal structure of the functional block of the partner to be combined. [Structure] Each functional block monitors an input coupling terminal for receiving a signal given to the functional block, an output coupling terminal for outputting a calculation result, and an arithmetic processing operation and input / output data executed in the functional block. Then, other functional blocks connected to the I / O coupling terminal determine whether or not initialization is required, and if initialization is required, status information indicating that is output is output via the I / O coupling terminal. The determination unit and the initialization unit that receives the status information from the outside of the function block indicating that initialization is required via the input / output coupling terminal and initializes its own function block are configured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control arithmetic unit for performing process control using a computer, and more specifically, to a software element for performing a predetermined arithmetic operation on an input signal and outputting an arithmetic operation result. The present invention relates to a control arithmetic unit that forms a desired control system by appropriately combining a plurality of functional blocks (which are also generally called internal meters).

[0002]

2. Description of the Related Art As a device for controlling a process, a distributed control system using a computer has been widely put into practical use. Such a distributed control system is composed of an operation monitoring device (operator station) having a man-machine interface function and a distributed control arithmetic device (control station) in charge of control arithmetic. On the side, functional blocks consisting of software elements that perform a predetermined calculation on the input signal and output the calculation result are appropriately combined in multiple building block formulas to suit the process to be controlled. The constructed control system is downloaded.

In such a control system provided (downloaded) in the control arithmetic unit, a change in the operation state such as an operation mode changeover or an input / output signal changeover is carried out so as not to give a disturbance to the process to be controlled. On the other hand, a function to prevent sudden change (bump) is incorporated in each functional block so that the control output does not suddenly change. For example, in a control system that is completed with one functional block, the output tracking function that matches the output signal from the functional block with the actual output given to the operating end from the local operating equipment on site, and the function during manual operation It incorporates a major tracking function that matches the set value given to the block with the process amount (measured value), and is configured to prevent bumps.

On the other hand, when a control system is constructed by appropriately combining a plurality of functional blocks, it is not possible to completely prevent output bumps only by preventing bumps closed by a single functional block. For example, in a cascade control system configured by connecting two functional blocks in a cascade, the functional block as the primary controller monitors the state of the functional block as the secondary controller. When the cascade coupling is broken due to switching the mode to manual adjustment or the like, processing for tracking the primary side output value to the secondary side set value is required.

Conventionally, the following technique has been adopted as a bump prevention measure across a plurality of functional blocks. (A) The original functional block (primary-side functional block) that outputs the signal retrieves information of the output-destination functional block (secondary-side functional block) as necessary to determine the timing of initialization (tracking, etc.). to decide. (B) All of the control function blocks in which the output bump is a problem are velocity-type outputs so that the signal value at the output destination changes only for the change in the current calculation.

[0006]

However, the above method (a) relates to the internal structure (data structure, processing structure, etc.) of the functional block of the partner to be combined in order to retrieve the information necessary for the initialization timing determination. There is a challenge of having to know the knowledge. The need for knowledge of other functional blocks goes against the independence of functions, which is one of the purposes of functional blockization.

Further, when a new type of function block is added, when the existing function block and the new function block are combined, the processing program of the existing function block is taught the internal structure of the new function block, and the functions of both functions are combined. There is a problem that it is necessary to perform a modification process so that the blocks can cooperate with each other. The above method (b) has no problem when the control system is composed of a functional block for performing speed type output. However, if a complex control system is to be configured, there is a possibility that the system may include a function block that essentially performs position type output (for example, a function block that functions as a computing unit or a program setter). In this case, it is necessary to perform special handling processing according to the control system.

The present invention has been made in view of the above points, and does not impede the function independence of each functional block when a plurality of functional blocks are combined to form a desired control system. An object of the present invention is to provide a control arithmetic unit capable of preventing output bumps without depending on whether the function block is a speed type output or a position type output.

[0009]

According to the present invention which achieves such an object, a control system is constructed by combining a plurality of functional blocks each of which is composed of software elements for performing a predetermined calculation on an input signal and outputting a calculation result. In the control arithmetic unit, an input coupling terminal for receiving a signal given to the functional block, an output coupling terminal for outputting a calculation result, and an arithmetic processing operation executed in the functional block. And / or monitoring the input / output data, determining whether or not the initialization is required on the side of the other functional block connected to the input / output coupling terminal, and if the initialization is required, the status information indicating that is sent in advance. Initialization judging means for outputting via the input / output coupling terminal, and status information indicating that the initialization given via the input / output coupling terminal is necessary, A control arithmetic apparatus characterized by comprising an initializing means for initializing the functional blocks of the body.

[0010]

Operation: The initialization determining means in the function block monitors the movement of the function block processing program and the input / output data. For example, when there is a change in the operating state of itself, other function blocks connected to the function block. If it is determined that the initialization is necessary, the status information indicating that the initialization is necessary is output via the input / output coupling terminal. This status information is transmitted to the other functional block side coupled to the functional block via the input / output coupling terminal.

The initialization means of the other functional block receives the status information indicating the initialization need, which has been transmitted, and performs its own initialization processing.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a configuration block diagram showing an embodiment of the present invention. In this figure, a case where two functional blocks are combined to form a cascade control system is illustrated. In the figure, FC indicates a control arithmetic unit using a computer, and PR indicates a process controlled by this control arithmetic unit. In the control operation device FC, 1 is a first functional block, which functions as a primary controller here, and is a signal PV from the sensor SN1 installed in the process PR.
Enter 1. Reference numeral 2 is a second functional block which functions as a secondary controller. The signal PV2 from the sensor SN2 installed in the process PR is input and the output signal MV1 from the first functional block 1 is Set value SV
2 and the calculation result (control output) MV2 is combined so as to be sent to the operating end VA such as a valve.

In each of the first and second functional blocks 1 and 2, 10a and 10b are supplied with an input signal (a set value signal is also treated as an input signal), and an input / output coupling terminal 11 outputs an operation result. This is an output coupling terminal.
Each of these input / output coupling terminals is composed of information defining the input destination of the input signal of the functional block and the output destination of the output signal, and the functional block passes through these input / output coupling terminals,
The signal (data) outside the functional block can be referenced or set.

Reference numeral 12 is an arithmetic processing means for performing a predetermined arithmetic operation, for example, a feedback control arithmetic operation, a sequence control arithmetic operation, a numerical arithmetic operation, a logical arithmetic operation and the like. This arithmetic processing means 12 has a signal applied to the input coupling terminal 10a, for example, a measurement signal PV1 (PV2) and a signal applied to another input coupling terminal 10b, for example, a set value SV1.
The deviation from (SV2) is subjected to a control operation, and the operation result is output to the output coupling terminal 11 by a software element.

Reference numeral 13 monitors the arithmetic operation or the input / output data being executed in its own functional block, detects, for example, a change in its own operating state, and outputs the input / output terminal 10.
The other functional block connected to 11 judges whether or not the initialization is necessary. If the initialization is necessary, the status information indicating that is output to the outside of its own functional block via the input / output coupling terminal. The initialization determining means 14 performs initialization of its own functional block based on this status information when it receives status information given from outside the functional block, which indicates that initialization is required, through the input / output coupling terminal. It is a means.

In this example, the output coupling terminal 11 of the first function block 1 and one input coupling terminal 10b of the second function block 2 are connected to each other, and the first function is provided between them. Data of the calculation result is output from the block 1 to the second functional block 2, and initialization is necessary from the initialization determining means 13 in the second functional block 2 to the first functional block 1. In such a case, status information indicating that is output.

As described above, the first functional block and the second functional block
The work of constructing a desired control system by combining the functional blocks of (1) and (2) in a building manner shall be performed using a workstation or an engineering station having a builder function (not shown). The operation of the device configured as described above will be described below.

FIG. 1 shows an example in which two functional blocks 1 and 2 are combined in a cascade connection to form a cascade control system. Both of the two functional blocks 1 and 2 are feedback for performing PID control calculation. The one that performs control calculation is used. 1 in cascade control status
The first functional block 1 as the secondary controller is the sensor SN
The PID control calculation is performed on the deviation between the signal PV1 from 1 and the set value SV1, and the calculation result MV1 is given to the second functional block 2 as the secondary controller as the set value SV2. In the second function block 2, the PID control operation is performed on the deviation between the signal PV2 from the sensor SN2 and the set value SV2 given from the first function block 1, and the operation result MV2 is output to the operation terminal VA. I do.

In such a normal cascade control state,
The initialization determining means 13 in each functional block determines that the initialization is not necessary in other functional blocks, and does not operate the status information output to the outside of the functional block. Next, in the second function block 2, for example, it is assumed that the cascade control state is opened and the mode is changed to the automatic adjustment state in which the control calculation is performed based on the set value of the function block 2 of itself.

In this case, the initialization judging means 13 in the second functional block 2 monitors the operation of the arithmetic processing means 12 and detects this mode change. Then, from the contents of this mode change (change from the cascade control state to the automatic adjustment state), it is determined that the first function block 1 side needs initialization, and the first function block 1 side is input through the input coupling terminal 10b. Operate the status information output to. Here, as a method of transmitting this status information, for example, the data status of the register for storing the set value SV2 for receiving the data given to the input coupling terminal 11b of the second functional block 2 is operated (set). Alternatively, the initialization means 14 of the first function block 1 may read back the operation of the data status.

In the first functional block 1, when the initialization means 14 detects the status information transmitted (read back) through the output coupling terminal 11 and indicating the need for initialization, the initialization of the first functional block 1 is performed. And perform output tracking. This output tracking operation is
The operation value MV1 output from the output coupling terminal 11 of the first function block 1 follows the set value used in the second function block 2 (in the automatic adjustment state). The first function block 1 is realized by reading the set value used in the second function block 2 at a constant cycle through the input coupling terminal 10b of the second function block 2.

As a result, when the mode is changed to the cascade control state as the cascade close, the mode change can be bumplessly performed. FIG. 2 shows a combination of a functional block having an auto-selector function for inputting a plurality of signals and automatically selecting one of the signals and a functional block having a PID control calculation function, thereby performing auto-selector cascade control. It is an example of configuring the system.

In the figure, reference numeral 1 is a PID control calculation function block, and the output data of this block is represented by MV. Reference numeral 3 denotes an auto selector function block, which represents three input data by RV1, RV2, and RV3. The output coupling terminal 11 of the control calculation function block 1 and one input coupling terminal 10b of the auto selector function block 3 are coupled. is doing.

The initialization judging means 13 in the auto selector function block 3 monitors the operating state of the switch,
When the switch is switched, it is determined that the initialization is necessary, and the status information indicating that is operated. Here, the data status of the input data RV2 applied to the input coupling terminal 10b is operated (for example, set to active). In the control calculation function block 1, the initialization means 14 outputs the input data RV2 to the output coupling terminal 11 and the input coupling terminal 10b.
The data status of the input data RV2 is detected, the operation is initialized, and the output MV of the control operation function block 1 is read through the input data RV.
The output tracking operation is performed so as to follow 2.

As a result, when the automatic selector function block 3 next changes to a mode for selecting the output data from the control calculation function block 1, the switching can be performed bumplessly. FIG. 3 shows two functional blocks 1,
FIG. 3 is a configuration block diagram when a cascade control system is configured by combining two so as to be cascade-connected. In this example, in the second function block 2, the cascade setting data is CSV and the setting value given to the secondary controller is SV.
, And it is assumed that the setting value SV is set from outside the functional block.

In this case, in setting the external data, a program (data access program) for setting data from the outside sets a data value and operates status information indicating that initialization is necessary. In the first functional block 1, the initialization means 14 detects the status information transmitted through the output coupling terminal 11 and indicating the initialization necessity.
The function block 1 is initialized and output tracking is performed.

As a result, the output bump can be prevented even when the mode is changed or the data is set at a timing unrelated to the first functional block 1 side.
FIG. 4 shows, as a functional block, a functional block 4 for performing, for example, a polygonal line function calculation on an input signal from the sensor SN (this calculation function block does not have means for initializing itself. ) And a functional block 1 having a PID control calculation function for inputting a signal from the functional block 4 are combined to form a control system.

In the function block 4 for performing the polygonal line function calculation, 40 is a polygonal line function calculating means, and the initialization judging means 13 also monitors a signal (process input) input to the polygonal line function calculating means 40. Upon recovery from the abnormal state of the process input, it is determined that the functional block 1 side needs to be initialized, and the data status information of the operation output data MV output from the functional block 4 is manipulated.
On the functional block 1 side, the initialization means 14 outputs the operation output data MV from the functional block 4 transmitted to itself.
From the data status information of (this data is treated as the cascade setting data CSV on the functional block 1 side), it is detected that initialization is necessary, and calculation initialization and output tracking operations are performed.

As a result, when the abnormality of the process input is recovered, a situation occurs in which the input data suddenly changes (usually in the function block 4, when the process input suddenly changes, the operation output data MV also suddenly changes). However, on the functional block 1 side, the cascade setting data CSV
Can be prevented from bumping. In the above embodiments, the functional blocks having the PID control operation function, the auto selector function, and the polygonal line function operation function are exemplified. However, those having the sequence control operation function and the switch function, The same can be applied to a case where a control system is constructed by combining functional blocks having various functions that are newly developed.

[0030]

As described in detail above, the present invention is
In the case of connecting a plurality of functional blocks to form a desired control system, through standardized input / output coupling terminals,
Since the status information indicating the necessity of initialization is transmitted, the initialization process for preventing signal bumps can be easily performed without knowledge of the internal structure of the functional block of the partner to be combined. Therefore, it is possible to realize a control arithmetic unit capable of easily constructing a control system suitable for various processes.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention.

FIG. 2 is a configuration block diagram in the case where an auto selector cascade control system is configured by combining two functional blocks.

FIG. 3 is a configuration block diagram in the case where a cascade control system is configured by combining two functional blocks in a cascade connection.

FIG. 4 is a configuration block diagram in the case where a control system is configured by combining a functional block that performs a polygonal line function calculation as a functional block and a functional block having a PID control calculation function.

[Explanation of symbols]

 FC control arithmetic unit PR process 1, 2, 3 functional block 10 input coupling terminal 11 output coupling terminal 12 arithmetic processing means 13 initialization determination means 14 initialization means

Claims (1)

[Claims] 1. A control arithmetic unit for constructing a control system by combining a plurality of functional blocks composed of software elements for performing a predetermined arithmetic operation on an input signal and outputting an arithmetic operation result, wherein each of the functional blocks comprises: An input coupling terminal for receiving a signal given to a functional block, an output coupling terminal for outputting a calculation result, an arithmetic processing operation and / or input / output data being executed by the functional block are monitored, and the input / output coupling terminal is connected to the input / output coupling terminal. An initialization determination means for determining whether or not the initialization is necessary on the side of the other functional block to be connected, and for outputting the status information indicating that the initialization is required through the input / output coupling terminal, Initialization means for receiving the status information that indicates that initialization is required via the input / output coupling terminal and performing initialization within its own functional block. Control arithmetic apparatus characterized by digit.