JPH0331904A - Programmable controller - Google Patents

Abstract

PURPOSE:To obtain a rational programmable controller to execute a flexible control by adding a knowledge inference part and a knowledge storage part inside the programmable controller and executing an inference action when a specific event such as a trouble is generated in parallel to a sequence/ arithmetic control action. CONSTITUTION:A production system rule is stored in a knowledge storage part 6, and when the specific event is generated, an interruption is applied from a sequence/arithmetic control part 1 to a knowledge inference part 5. The knowledge inference part 5 executes the inference based on the input information of a sequence/arithmetic data storage part 3 and the rule in the knowledge storage part 6. The control is executed based on an inference result, and simultaneously, when the control is completed, the interruption is applied to the sequence/arithmetic control part 1, and a completion is reported. Thus, the sequence/arithmetic part 1 can continue the action while the knowledge inference part 5 executes the inference, and the rational programmable controller to execute the flexible control can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a programmable controller that includes a processor that performs sequence operations as well as a processor that has an inference engine function.

(Prior Art) The basic configuration of a programmable controller is shown in FIG.

7th r! At 74, the sequence calculation control unit 1 takes in the input signal from the input/output unit 4 via the data bus 2,
It generates a control output according to the control logic built into the sequence/calculation data storage section 3, rewrites the data on the sequence/calculation data storage section, and controls the operating equipment via the data bus.

O8 (operating system) is resident on the sequence/calculation data storage unit, and when the sequence/calculation control unit receives a user program execution instruction, the sequence/calculation control unit retrieves instructions from the sequence/calculation data storage unit and sequentially executes them according to O8. When you run and reach the end of your user program,
That is, when the niscan is completed, control is returned to O8 again.

The user program is usually given in the form of a ladder diagram that describes turning on and off relays.

Specifies sequence instructions and numerical data arithmetic processing.

In order to perform program control flexibly, it is desirable that the control rules include not only ladder sequences but also rules based on production system rules.

The production system rule is if-th as follows
enthsn.

if (Start condition l is true) (Start condition 2 is true) thsn (Conclusion fact 1 is true) (Conclusion fact 2 is true) By using this, you can calculate the failure based on the input information when the failure occurs. The causes can be described, and control is performed by deriving a rule that makes the activation condition true when a failure actually occurs.

However, when controlling based on the above production system rules using the programmable controller shown in Figure 7, (1) all the rules must be made into ladder sequences, which takes time and effort to express vague knowledge; Not easy to expand.

■ Ladder sequence control is normally interrupted when a failure is detected, the cause is identified, and the corresponding control is performed.

There are other problems.

(Problems to be Solved by the Invention) As mentioned above, with the configuration of the conventional programmable controller, it is difficult to perform operations other than the normal sequence, such as inferring the cause when a specific event such as a failure occurs. .

The present invention adds a knowledge inference section and a knowledge storage section inside a programmable controller, and performs inference operations when a specific event such as a failure occurs in parallel with sequence/arithmetic control operations, thereby enabling flexible control. The purpose is to provide a rational programmable controller that can

[Structure of the invention]

(Means and effects for solving the problem) The present invention compiles production system rule-type knowledge in addition to a sequence/calculation control processor that executes sequence control rules based on ladder diagrams, numerical data calculations, and O8. It is equipped with a knowledge inference processor consisting of a knowledge storage section that stores code that has been generated, and a knowledge inference section that makes inferences based on sequence/operation data and knowledge.・It is a programmable controller that performs inference in parallel with arithmetic control. Production system rules are stored in the knowledge storage section, and when a specific event occurs, the sequence/arithmetic control section interrupts the knowledge inference section, and the knowledge inference section performs inference based on the input information in the sequence/calculation data storage unit and the rules in the knowledge storage unit, performs control based on the inference results, and when the control is completed, interrupts the sequence/calculation control unit to notify the completion. do.

This allows the sequence/arithmetic $II control section to continue operating even while the knowledge inference section is performing inference.

(Example) An embodiment of the present invention is shown in FIGS. 1 to 3.

FIG. 1 is a basic system configuration diagram of the present invention, FIG. 2 is a system diagram showing a specific configuration corresponding to FIG. 1, and FIG. 3 is a flowchart showing its operation.

In FIG. 1, a knowledge inference section 5, a knowledge storage section 6, and a control signal bus 7 are added compared to the conventional FIG. 7.

Moreover, as shown in FIG.
Ladder sequence control information and production system rules are stored through the sequence calculation data storage device M1 and rule knowledge bag, respectively! Store in M3. Note that O8 is kept resident in the standard device Ml.

When a control start command is given from the input/output device 4, the arithmetic control processor source 2 sequentially fetches and executes the user program from the storage device Ml, and if the instruction is a sequence control instruction, it is sent to the sequence control processor P1. Let it run.

The user program is created by linking a ladder sequence file 22 and a rule file 23, as shown in FIG. In FIG. 4, 18 is a ladder sequence source file, 19 is a rule source file, and 20 is a ladder sequence source file.
is an assembler, and 21 is a compiler.

24 is a linker, and 25 is an executable file.

Each object file has a structure as shown in Figure 5. The header records the size of the code area, data area, symbol information area, and various identifiers, and the symbol information includes the locator pull address for linking. is recorded.

e.g. relay 1 by the assembler or compiler
is R○1, relay 2 is symbol-converted as R○2, the same type of input/output devices are unified by the ladder sequence and rules, and the linked execution modules are stored in the storage devices ff1M1 . The original file is divided into three parts and loaded.

The storage device Ml is divided into an O8 portion, a sequence instruction portion, and a data portion, and the same data as the storage device Ml is recorded in the storage bag [original 2].

Storage device source 2 is a dual port memory and is accessible from both the internal bus and processor P3.

In addition, a storage device control circuit 16 is provided so that the data in the storage device Ml and the storage device original 2 are the same, and this circuit controls the execution of the processors P1 and O8, which perform only sequence instructions, and the processor P2, which performs numerical operations. When one of the two generates a write control signal for the memory bag [Ml, it simultaneously outputs a write signal to the same address for the memory bag [Original 2] and also generates a read signal, the memory device [Ml Control is performed so that the data output from Ml is written to the same address on the storage device 1M2, so that all the data accessed by the user program is the same in the memory bag [Ml] and the memory bag [Original 2]. .

When control is transferred from O8 to the user program, processor P2 decodes the instruction, and if it is a sequence instruction, it is executed by processor P1, and other instructions are sequentially fetched from storage device 1M1 and executed step by step.

During this time, data identity is maintained between the memory bag [Ml and the storage device base 2].

Next, the operation when a specific event occurs will be explained with reference to the flowchart shown in FIG.

When processor P2 receives an interrupt corresponding to a predetermined specific event, processor P2 interrupts inference processor P3 as shown in FIG. 6, and when processor P3 receives an interrupt from processor P2, it interrupts storage device [ The storage device control circuit 16 sequentially reads and executes the knowledge base code from the source 3 to ensure that the data being inferred is the data at the time the event occurred.

At the same time as the processor P2 issues an interrupt to the processor P3, writing to the internal data of the storage device source 2 is prohibited.

Processor P3 thus makes inferences based on the knowledge of storage pair 3 and the data of storage original 2, while processor P2 continues its sequence control operations.

When the processor P3 finishes the inference, it writes the inference result into a predetermined area of the storage device 12, and issues an interrupt to the processor P2 to notify the end of the inference.

As a result, the processor P2 refers to the inference result from the storage bag [original 2] and performs operations such as outputting it to one of the input/output devices 4, for example, a CRT.

Simultaneously with the completion of the inference, the storage device control circuit 16 again updates the data in the storage device original 2 to the data in the storage device M1 using the method described above, and after the niscan time, the data becomes the same.

〔Effect of the invention〕

As described above, according to the present invention, it becomes possible to perform inference using a knowledge base during sequence control, thereby providing a rational programmable controller that performs flexible control.

[Brief explanation of drawings]

FIG. 1 is a basic system configuration diagram showing an embodiment of the programmable controller according to the present invention, FIG. 2 is a system diagram showing its specific configuration, FIG. 3 is a flowchart showing its operation, and FIG. FIG. 5 is a diagram showing a user program creation method, FIG. 5 is a diagram showing the structure of a user program object file, FIG. 6 is a timing diagram of inference operation, and FIG. 7 is a system configuration diagram showing an example of a conventional programmable controller. . l... Sequence/calculation control unit 2... Data bus 3... Sequence/calculation data storage unit 4... Input/output unit 5... Knowledge inference unit 6... Knowledge storage unit
7... Control signal bus 14... Control line 1
5...Address 16...Storage device control circuit 17
... Gate 18 ... Ladder sequence source file 19 ... Rule source file 20 ... Assembler 21 ... Compiler 22 ... Ladder sequence object file 23
...Rule object file 24...Linker 25...Executable file M
L, M2...Sequence/calculation data storage device M3/
...Rule knowledge storage device Pl...Sequence control processor P2...Arithmetic control processor P3...Knowledge inference processor

Claims (1)

[Claims] A sequence/arithmetic control unit that executes the operating system, arithmetic processing of input/output data, and ladder sequence execution, a sequence/arithmetic storage unit that stores data used for the above arithmetic control, an input/output unit, and an input/output unit between these. In a programmable controller equipped with a data bus for transmitting data, a knowledge storage unit stores code compiled from a knowledge base written in the form of production system rules, and knowledge for making inferences based on the stored data and the knowledge base. When an event occurs, the knowledge inference unit is activated by an interrupt from the inference unit and the sequence/calculation control unit, and when the inference is completed, the knowledge inference unit interrupts the sequence/calculation control unit to notify the completion of the inference. A programmable controller characterized in that the programmable controller is provided with an interrupt function that writes an inference result to the knowledge storage section and allows the sequence/arithmetic control section to refer to the inference result.