JPH01287709A - Sequence controller - Google Patents

Abstract

PURPOSE:To easily trace the cause of abnormality in case of generating the abnormality due to an unknown cause by providing an analysis means to retrieve the decision equation of a program and to decide the truth/false of an input/output value when the abnormality is generated, a storage means to store the specification of input/output and a retrieval content at the time of performing analysis, and a display means to display a storage content. CONSTITUTION:The analysis means 5 performs the decision of the truth/false of a decision text in the program when the abnormality is generated in a mechanical device. At this time, when the said internal input is set as false due to the non-execution of an output text, it means that the decision text which performs condition establishment waiting before the output text exists and execution is interrupted at that point. Therefore, by repeating the decision and the retrieval of the decision text, all of the external input can be found finally. In other words, either the external input represents the cause of the abnormality. In such a way, by displaying the analyzing process and the input value at that time on the display means 7, it is possible to trace the cause of the abnormality easily.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a sequence control device, and particularly to a sequence control device suitable for easily investigating the cause of an abnormality when an abnormality occurs in program execution. Regarding.

[Conventional technology]

A sequence control device generally executes a program consisting of an output formula for giving some kind of electrical or mechanical command to a mechanical device to be controlled, and a determination formula for determining the state of the mechanical device. In addition, the outputs issued by operation commands include external outputs that are directly given to the mechanical device, and internal outputs that are used for state maintenance and temporary storage.Similarly, the inputs include external inputs that are directly read out from the mechanical device. It consists of an internal input that reads out the value of the time memory, etc., and,
When a program start command is given, the above-mentioned judgment formula and output formula are sequentially and alternately executed.During the execution, if an abnormality occurs at a certain condition judgment stage, for example, JP-A-61 As described in Japanese Patent No. 156407, information for restoring the mechanical device is provided to the user by displaying the contents when the sequence is stopped.

[Problem to be solved by the invention]

In the above conventional technology, if the cause of an abnormality is known in advance, all the causes of the abnormality are restored and stored in the control device, and when an abnormality occurs, the cause of the abnormality is selected from the list and displayed. It is possible to do so. However, if the cause is unknown, the above method cannot be used, and the user ends up checking the program list and external input values representing the machine status in detail one by one.

In the above programs, a series of processing is generally written as multiple programs, and their execution is also performed simultaneously in parallel. Therefore, regarding input/output (especially internal input/output), there is a slight difference in synchronization between parallel processing. and shi are often present,
These analyzes require a lot of time and effort, and the cause of the abnormality cannot be easily determined.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sequence control device that can easily identify the cause of an abnormality even when an abnormality occurs due to an unknown cause.

[Means to solve the problem]

The above purpose is to provide an analysis means that searches the judgment formula of the program and determines the truth or falsehood of input/output values when an abnormality occurs, a storage means that stores the type of input/output and search contents at the time of analysis, and a display of the storage contents. ◎ [Operation] The analysis means determines the truth or falsity of the input/output values of the judgment statement in the program when an abnormality occurs in the mechanical device. At this time, the input/output is internal. In the case of input, search the program for the output statement that set (output) the internal input. - If the internal input is false because the output statement has not been executed yet, then search for that output statement. If there is a judgment statement that waits for the condition to be met before , execution should have been interrupted at that location. Therefore, by returning the above judgment/search for the judgment statement, In the end, everything comes down to external input. That is, any of these external inputs represents the cause of the abnormality. Therefore, by displaying the analysis process and input values at this time, it becomes easier to pursue the cause of the abnormality.

〔Example〕

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

FIG. 1 is a block diagram of a sequence control device according to an embodiment of the present invention. A normal sequencer has program storage means 1. which is a memory for storing execution contents of sequence control. Execution means 2 is a sequence control processor that performs execution according to the contents, internal input/output storage means 3 temporarily stores internal input/output among input/outputs that are the result of execution, and external equipment among input/outputs. It consists of external input/output means 4 for inputting and outputting signals.

The execution means 2 sequentially executes each statement of the program stored in the program storage means 1 while reading and writing from and to the input/output means 6.4. As mentioned above, if an abnormality occurs in the external device, the external input will be different from the value intended by the program, making it difficult to execute the program, and in the worst case, the program will stop executing.

Therefore, in this embodiment, the analysis means 5 analyzes the contents of the program, searches for a condition waiting line, extracts the input/output variables in the conditional expression, and performs the truth/false determination and type determination of the input variable; An analysis result storage means 6 for storing intermediate results and final results generated during analysis in a stack format, and a display means 7 for displaying the contents of the analysis result storage means 6 on the screen are newly installed to prevent the user from seeing abnormalities. The variable name and value are presented for a certain external input. 〇Figure 2 shows 70- of the analysis processing procedure executed by the analysis means.
It is a chart. When the analysis means 5 is activated, the analysis means 5 performs a program execution line reading process in step S1, and informs the execution means 2 which part of each valley program that is being simultaneously processed is being executed. Inquire. Here, as shown in Fig. 3, there are currently multiple programs (in the example of Fig. 3, program 1 and program 2).
are executed at the same time, for example, program 1 is executed at line level 3''!.In this case, for program 1, the 0th step S to read execution line limit 3 is executed.
In the program analysis process No. 2, if the execution wait read in step S1 is a condition wait, the input/output in the conditional expression is cut out. Above <3 (WAIT XOI AND
XO2AND RO5) is a conditional wait statement, which waits for the AND condition of external inputs XOI and XO2 and internal input/output RO5 to be met.

In the input/output value reading in step S3, the input/output values found in step S2 are sequentially read from the internal input/output storage means 3 and the external input/output storage means 4. Then, in the authenticity determination process of step S4, the input/output values read out in step S5 are determined to be true or false. The judgment result is true (Y)
If so, it is determined that there is no problem with that input/output, and the process proceeds to the next input/output determination process (step S9) ◇ If the determination result in step S4 is false (N), then the internal input is determined in step S5. Proceeding to output determination processing, the type (internal, external) of the input/output for which a "false" determination has been made is determined.

If it is determined in step S5 that the type is external input/output, the process proceeds to step S+O and the name of the input/output is registered. If it is determined in step S5 that the type is internal input/output, the process proceeds to program search processing in step S6, and the internal input/output found in step S5 is found at another location in another program. Search to see if the table is set.

Then, in the setting row floor registration process in step S7, the Nh of the internal input/output assignment row found by the search in step S6 is
(for example, the line limit 20 of the program 2 in FIG. 3) are sequentially registered in the analysis result storage means 6.

In the next step S8, a search is made to see if there is a condition determination line in the line before the registered set line limit. In the example of FIG. 3, line limit 17 of program 2 is searched in step S8.

Regarding the condition determination of this search result, the process is repeated from step S1.

In the next input/output determination process of step S9, which is proceeding from step S4, it is determined whether or not there is any further input/output in the conditional expression, and if so, steps S3 and subsequent steps are repeatedly executed.

In the input/output name registration process of step StO that proceeds from step S5, the external input/output name determined in step S5, for example, XO2 in FIG. 3, is stored in the analysis result storage means 6. At this time, the line limit of the conditional expression being judged at that point is also registered (for example, in the example in Figure 3, line Nn
5).

If it is determined in step S9 that input/output no longer exists in the conditional expression, the process proceeds to step S11, which is a registration determination process, and checks whether the above process has been performed for all row floors that have been searched and registered. Determine whether or not. In this judgment, if it is determined that there is a remaining item, the registration attachment of the remaining item is read out in the registration property reading process of step S12, and the registration attachment of the remaining item is read out in step S12.
Return to 1.

If it is determined that there is no remaining program as a result of the determination in step Stt, step S [performs other program determination processing and determines whether or not the processing from step S1 has been executed for other programs as well. do. If the processing from step 81 onwards has not been executed for other programs, return to step S1, and step 81 for other programs as well.
When the following processing is completed and the analysis of the entire program is completed,
Proceeding to step S1, the analysis result is read out from the storage means 6 and displayed on the display means 7 as shown in FIG. Since this can be done quickly, the recovery of the device is quick and the downtime of the device can be shortened. Furthermore, by recording the content presented by the present invention, it can be used as a reference for future information on which parts are likely to cause abnormalities, and is effective in improving the reliability of the device.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a sequence control device according to one embodiment of the present invention, FIG. 2 is a flowchart of the analysis method I'Ill executed by the analysis means shown in FIG. 1, and FIG. 3 is an analysis FIG. 4 is a diagram showing a symmetrical program and a display example. 1... Program storage means, 2... Execution means, 3.
... Internal input/output storage means, 4. External input/output storage means, 5. Analysis means, 6. Analysis result storage means, 7.
...Display means G 1st I ¥1 jFt20

Claims (1)

[Claims] 1. A storage unit that stores a program representing a series of control procedures for controlling a mechanical device, an execution unit that executes the program, an external input/output to the mechanical device, and a storage unit that stores external input/output values; an external input/output interface section;
It is equipped with a storage unit that stores internal input/output values, and includes an output statement that provides an external output among the operation commands for each storage unit or external input/output interface unit, and a corresponding response from the mechanical device side. In a sequence control device that executes a program consisting of judgment statements that logically judge external input and internal input values read from internal storage, analysis that searches the judgment expression of the program and determines the truth or falsehood of input/output values when an error occurs. What is claimed is: 1. A sequence control device comprising: a storage means for storing input/output types and search contents during analysis; and a display means for displaying the stored contents.