JPS6275806A - Sequence controller - Google Patents

Abstract

PURPOSE:To reduce the labor for production of a decision table for each type of products and also to reduce the memory capacity, by using a table for designation of type-based conditions and actions and rewriting the columns for condition signals, etc. of the decision table in accordance with the operating conditions. CONSTITUTION:A table 15b for designation of type-based conditions and actions is provided to a storage 15. The name of the table 15b is supplied by the key input of an operator and in response to the type and the production line of a controlled system 20. Then a decision processing part 13 exchanges the condition signal column with the action signal column of a decision table 15a by the selected table 15b in the storage 15. The sequence control of the controlled system 20 is carried out by the table 15a. In other words, the part 13 performs the collation between the input signal given from the controlled system 20 and the corresponding sequence transition conditions. Thus the time to actuate the table 15a for each operating conditions can be omitted. This can reduce the labor for design and test of the table 15a and also reduce the memory capacity despite many types of products.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a sequence control device, and in particular to a device in which various information related to sequence control is written in a decision table, and a computer performs sequence control using the information in this table. It is related to.

[Technical Background of the Invention and Problems Therewith] A conventional general decision table is provided in a storage device of a computer, and is divided into four parts (top, bottom, left and right). The upper left part is a condition signal column, in which an input signal from the controlled object that becomes a sequence transition condition is specified. The lower left section is an operation signal column in which the output signal to be given to the controlled object is specified.

The upper right corner is an input condition specification column, in which information serving as a sequence transition condition corresponding to the input signal in the condition signal column is written in advance. The lower right corner is an operation output designation column, in which operating conditions for the controlled object are written in advance. The columns of the input condition specification field and the operation output specification field correspond to each other.

The operation state of the controlled object is specified in the condition signal column as one of the three input signals of "4111."'0゛'゛blank'', and each specified input signal is Corresponding sequence transition article 1'F ("
01'', ``00'', and ``Blank'' (2-bit signals). If the comparison results in that they all match, it is assumed that the ``condition is met'' and the sequence transition in the input condition specification field is performed. The operation signal in the operation output designation column in the column corresponding to the condition is applied to the operation signal column. The output signal from this operation signal field is output to the controlled object, and the next sequence control is performed.

By the way, the actual sequence in a chemical plant, etc. is not fixed, and when operating the same sequence by changing the type of product (hereinafter referred to as product type) or production line, the above condition signal column and operation signal Columns must be changed for each product type and production line.

However, in conventional sequence control devices,
Decision tables were set up according to the product type and production line, and the decision table was changed every time the product type or production line changed.

Therefore, it is necessary to create a large number of decision tables and store them in the storage device of the sequence control device at t31. The design of the decision table increases.

There was a problem in that tests, etc. required time and effort.

Another possible method is to store a decision table for each product type in disk memory and then transfer the decision table for the desired product type to RAM memory at the start of operation or during the process.
The testing process requires a lot of effort.

[Object of the Invention] The present invention has been made based on the above circumstances, and its purpose is to provide a sequence that reduces the effort required to create decision tables for each product type and reduces the storage capacity of a storage device even with a wide variety of products. The purpose is to provide a control device.

[Summary of the Invention] In order to achieve the above object, the present invention provides a sequence control device equipped with a decision table, in which the condition signal field and the operation signal field of the decision table are changed into products corresponding to the above operating conditions by an operator's key manual power or the like. The feature is that it can be rewritten using a type condition/operation specification table.

[Embodiments of the invention] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a sequence device according to the present invention.

The sequence control device 10 includes an input circuit section 11 connected to each operating end of the controlled object 20, a judgment processing section 13 mainly composed of a CPU, and a storage device 15, and the judgment processing section 13 includes: A condition input device 30 for inputting sequence conditions using an overerator or the like is connected.

The storage device 15 includes a decision table 15a, a product type condition/operation designation table 15b, and a crowd buffer area 15c, and signal transmission within the storage device 15 is performed according to instructions from the judgment processing section 13.

In this embodiment, the decision table 15a is configured as shown in FIG. That is, as described above, the decision table 15a is divided into four parts, vertically, horizontally, and horizontally, with the upper left section containing the condition signal column 41, and the lower left section containing the operation signal column 4.
3. The upper right corner is the input condition specification field 45. The lower right corner is an operation output designation column 47. A step number field 51 is arranged above the input designation g45, and this step number 1[1i
At the top of 151, a small process number column 53 is arranged.

Also, at the bottom of the operation output specification column 47, there is a next step specification 1.
1XI55 is placed. The next step designation field 55 is divided into upper and lower sections, with the upper part being a condition-sequential step designation field (hereinafter referred to as THEN field) 55a, and the lower part being a condition-unmatched next step designation field (hereinafter referred to as ELSE field) 55b.

Step numbers 1, 2 in the step number column 51. Each column of... is an input specification field 45. Operation output specification field 47, THE
The N column 55a and the ELSE column 55b correspond to each other and are the same step. Further, the rows of the condition signal field 41 and the input condition designation field 45 correspond to the rows of the operation signal field 43 and the operation output designation field 47, respectively.

The condition signal column 41 contains the control target 20 at the current step.
An input signal indicating the state of each operating end of is stored. This input signal becomes a transition condition for the sequence in the next step, and is a combination of signals in one of three states: 14 Q I+, 111'', and ``blank''.

This input signal is input from the controlled object 20 to the input/output circuit section 11, and is stored in the condition signal column 41 from the human output buffer area 15C of the storage device 15 through the judgment processing section 13.

The input condition designation 1IW45 stores in advance information about the normal or desired state of each operating end of the controlled object 20 at each step from the condition input wave M30. This stored information is a sequence transition condition to be compared with an input signal, and is composed of a combination of input signals and corresponding conditions in one vertical column.

In the operation output specification column 47, specify input conditions! Operation conditions under which each operation terminal of the controlled object 20 should operate are stored in advance from the condition input device 30 in a combination of one vertical column and one vertical column of each sequence transition condition 1145. The operating conditions are ""oooo","o.

oi'', ``This is a 4-bit signal with a blank pad.

In the operation signal field 43, among the operation conditions stored in the operation output designation column 47, the operation conditions for operating the operating end in the next step are stored. This stored content is “
With any output signal of QIZI"IIZII blank pad,
I/O buffer? It is stored in area 15C.

The condition signal [
The step number of the transition destination when all of the input signals of 41 and the sequence transition conditions of the step numbers corresponding to this input signal match is specified.

ELSEW55b, like THENJ)1!55a, specifies the step number of the transition destination when the input signal and the sequence transition condition do not match.

The memory 15 of this embodiment is provided with nine product type condition/operation designation tables 15b, as shown in FIG. This product type condition/operation designation table 15b sets condition signals 1111141 and operation signals 43 for each product and production line (referred to as grade) in the chemical manufacturing process, for example. This table 15b
is selected by the operator through the judgment processing section 13 by manual key operation of the condition input device 30, and the condition input @II! of the decision table 15a is now selected. 41 and the operation signal 11143 are exchanged.

Next, the operation of this embodiment will be explained using the flowchart of FIG.

First, a type condition/operation specification table name corresponding to the type and production line of the controlled object 20 is inputted by the operator's key power (step 401). The decision table 15a is based on the product type condition/operation specification table 15b.
Replace the condition signal 11141 and operation signal @ field 43 (
Step 403).

Then, according to the decision table 151), 1rIIJ
Sequence control of the I11 target 20 is executed as follows (step 405). That is, first, the input signals from each operation end of the controlled object 20 in step 1 are stored in the condition signal 1lI41, and the judgment processing unit 13 executes a comparison with the corresponding sequence transition condition. If all the comparison results match, the operation conditions of the operation output 11147 of the same step are stored in the operation signal 43. This operation signal is transmitted to the controlled object 2 via the input/output circuit section 11.
0, and the controlled object 20 enters the next sequence control state. And T I-I E N with the same step number
Proceed to the step specified in column 55a.

On the other hand, if there is even one discrepancy in the verification results,
The process advances to the step specified in the ELSE column 55b with the same step number.

In this way, the controlled object 20 is sequentially controlled according to the decision table 15a.

As explained above, according to this embodiment, the product type condition/operation designation table 15b is provided, and the condition signal a1 of the decision table 15a is
41 and the operation signal 11143 can be rewritten, the effort of creating a decision table 15a for each operating condition can be omitted, and the effort of designing and testing the decision table 15a can be reduced.

Next, another example of a sequence control device using the decision table 15a will be shown.

In sequence process management operations, sequence steps are managed by dividing them into several small processes, and when an abnormality occurs in a certain sequence step, it is necessary to move from the previous sequence step to the next small process or go back. For example, start small process 1 → step 1
[Valve V open] → Step 2 [Pump P drive] →...
In the sequence control of step n [between valves V] → start of small process 2, an abnormality occurs in step 2,
If we move to small process 2 and continue the sequence, the valve V that should originally be closed at the beginning of small process 2
A situation arises in which the opening remains open.

In order to avoid the above-mentioned situation, it is necessary to set the start status of each small process to the correct one.For this reason, conventionally, the start status of each small process (operation step) must be set manually by the operator individually. changes were made. This is a very complicated task.

Furthermore, even if a specific operating end to be controlled is manually intervened to change the status to another, if the process proceeds automatically, the status will change again at the beginning of the next small process.

Therefore, in addition to the decision table 15a, the storage device 15 of the sequence control device 10 of this embodiment includes a leading status designation table 15 as shown in FIGS.
d is provided. This head status specification table 15d is used to set the head status of each small process to the correct status, and when proceeding through the sequence in automatic mode according to the decision table 15a,
When making process changes in manual mode, it operates as an overlay on the sequential processing sequence.

Further, as shown in FIG. 2, the decision table 15a is provided with a small process number column 53 in which each step indicated by step number [151 is divided into small process units.

This embodiment can be applied to the following sequence control. In the reaction towers (reaction towers or adsorption towers) Δ, B, and C shown in Figure 7, for example, if two towers are used for reaction and one tower is used for catalyst regeneration, and this combination is sequentially switched and controlled, each electromagnetic valve is used. 1A to 1F, 2A to 2F, and 3A to 3E are sequentially switched to form a line through which fluid flows. In this case, the sequence culm is [Stop 1-→[△-B line formation (between valves 10 and 18])→
[Between the person and outlet valves] → [Reaction execution] → [Inlet and outlet valves closed])
[[3-C line formation (valve 2D, 3 [3 open)] → [Inlet/outlet valve open → [Reaction execution] → [Input/output valve IJI] - child [C
-A line formation (valve 3D, IB open) → [inlet/outlet valve open 1 →
A process called [reaction execution] is executed. It is effective to use the head status designation table 15d of this embodiment when, for example, a process is to be transferred during execution of this processing process.

Next, the operation will be explained according to flowchart 1 in FIG. The sequence is sequentially advanced in automatic mode according to the decision table 15a, and if some abnormality occurs during the process, the operator operates the keys on the condition input device 20 in order to skip the current step and move on to the next small process. (Step 801 portrait).

Then, the judgment processing unit 13 calls the start status specification table 15 (the start status of the corresponding sub-process of l, -tas), sets the start status of the sub-process to the correct status, and then sets the processing of each step of the sub-process to the automatic mode. This is executed in step 803.

As explained above, in this embodiment, when an abnormality occurs in a certain sequence step and the sequence is moved to the next small process, the start status of the previous process can be set to the correct status using the start status specification table 15d. Therefore, the process of matching the leading status is simplified. As a result, the transition process for small processes can be easily performed.
The degree of freedom in operator intervention processing when an abnormality occurs increases.

[Effects of the Invention] As described above in detail, according to the present invention, a type condition/operation specification table is provided in a sequence control device equipped with a decision table, and the condition signal diagram of the decision table and the condition signal diagram of the decision table are set according to the operating conditions. Since the operation signal column is rewritten, the effort required to create decision tables for each product type can be reduced, and the memory size of the storage device can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a configuration diagram of a decision table, FIG. 3 is a configuration diagram of a product type condition/operation specification table, and FIG. Flowchart for explaining operation, FIG. 5 is a block diagram showing a storage device in another example of the sequence control device, FIG. 6 is a configuration diagram of a head status designation table, FIG. 7 is a diagram showing an example of a sequence processing step, FIG. 8 is a flowchart showing the processing procedure in another example of the sequence control device. 10... Sequence control device 13... Judgment processing section 15... Storage device 15a... Decision table 15b... Product type condition/operation specification table 15g Fig. 2 5b Fig. 3 Fig. 4 Fig. 5d 6 Figure reactant reaction product

Claims (1)

[Claims] A condition signal field where the input signal from the controlled object is specified, an operation signal field where the output signal to be given to the controlled object is specified, and an input where the sequence transition conditions corresponding to the input signals in the condition signal field are written in advance for each step. A decision table with a condition specification column and an operation output specification column in which the operating conditions for the controlled object are written in advance for each step, and a condition signal column and operation set for each operating condition such as the type of control object or production line. A storage device having a product type condition/operation designation table consisting of signal columns is provided, and the condition signal column and operation signal column of the decision table can be set to the product type condition/operation according to the operating conditions by an operator's key input or the like. A sequence control device characterized by rewriting using a designated table.