JPH032902A - Programmable controller - Google Patents

Abstract

PURPOSE:To attain an effective debugging task of a control program by using a data store memory which stores the contents of a data memory during an arithmetic operation of the control program with an external command and then displaying the contents of the data memory to the outside with an external command. CONSTITUTION:A programmable controller 1 contains a program memory 2, an input part 3, an arithmetic part 4, a data memory 5, an output part 6, and a data store memory 7 and is connected to a maintenance tool 8. Then the controller 1 stores the contents of the memory 5 in the memory 7 during an arithmetic operation of a control program. Therefore the contents of the memory 5 can be displayed to the outside during an arithmetic operation of the control program without affecting the execution of the computing operation of the control program. Thus an effective debugging task is facilitated for the control program.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention is directed to data processing in which external signal input, control program calculation, and signal output to external equipment are repeatedly executed, especially data in the middle of calculation. The present invention relates to a programmable controller capable of storing and displaying information.

(Prior art) Recently, programmable controllers have been widely used for automatic control of plants and other various types of equipment.Programmable controllers input the operating status of equipment from various sensors built into the equipment, and operate according to the status. Send instructions to each part of the equipment.

As shown in Fig. 5, a conventional programmable controller generally has an input section 3 for inputting external signals, a calculation section 4 for executing calculations of a control program, an output section 6 for outputting calculation results to external equipment, and a storage section for storing the control program. A data memory 5 stores external input signals and calculation results.

The programmable controller configured in this way is
Input processing for storing external input signals obtained through the input unit 3 in the data memory 5, calculating the control program stored in the program memory 2 according to the contents of the data memory 5, and storing the results in the data memory 5. Arithmetic processing and output processing for outputting the arithmetic results of the control program stored in the data memory 5 to an external device via the output unit 6 are repeatedly executed.

The control program for operating the programmable controller may have errors due to input errors during program creation or programming errors in the control program. Therefore, the created control program is stored in the program memory 2 of the program controller and then calculated. Normally, the contents of the data memory 5 during execution of the control program are displayed using a device such as a maintenance tool for debugging.

(Problem to be Solved by the Invention) Conventionally, the contents of the data memory displayed using a device such as a maintenance tool are only the final results at the end of the calculation of the control program, and the contents of the data memory during the calculation of the control program are displayed. No content is displayed.

However, the contents of the data memory may be rewritten at multiple locations in the control program, and therefore, in order to debug the control program efficiently, it is necessary to display the contents of the data memory during the operation of the control program. be.

As a means for this purpose, there is a method of providing the programmable controller itself with an address stop function that stops the calculation of the control program midway.

In this case, it is necessary to pass the calculations of the control program sequentially while changing the setting of the address where calculations are stopped.
There is a problem that not only debugging work is troublesome, but also that it is difficult to understand the continuous movement of control calculations.

Another method is to change the program to transfer and save the contents of the data memory to another unused area on the data memory during the control program, and then read the transferred data memory contents for debugging. However, changing the original control program for debugging may itself cause a program error in the control program during the program change process.

An object of the present invention is to provide a rational programmable controller that enables debugging by displaying the contents of data memory during the calculation of a control program without affecting the execution of the calculation of the control program. There is.

[Structure of the invention]

(Means and Effects for Solving the Problems) The programmable controller according to the present invention includes an input section for inputting external signals, an arithmetic section for executing arithmetic operations of a control program, an output section for outputting arithmetic results to an external device, and an Mfll.
Consists of a program memory section that stores programs and a data memory section that stores external input signals and calculation results.Input processing that stores input data obtained from the input section in the data memory section, and control programs stored in the program memory section. In a programmable controller that repeatedly performs arithmetic processing to perform calculations and output processing to output the calculation results stored in the data memory section to an external device via the output section, the contents of the data memory section during the calculation of the control program are A data storage memory area for storage, means for transferring the contents of the data memory section to the data storage memory area during the calculation of the control program, and means for displaying the contents of the data storage memory area are provided.

This makes it possible to externally display the contents of the data memory during the operation of the control program without affecting the execution of the operation of the control program, thereby facilitating debugging work.

(Embodiment) An embodiment of a programmable controller according to the present invention is shown in FIG.

In FIG. 1, a programmable controller 1 includes a program memory 2 that stores a control program, and an input section that inputs an external signal obtained from a controlled device (not shown) and converts it into external input data, as in the conventional FIG. 5. 3,
a calculation unit 4 that executes calculations according to a control program based on external input data from the input unit 3; It has a data memory 5 for storing external input data from the input section 3 and calculation results from the calculation section 4, and an output section 6 for outputting external output data stored in the data memory 5 as an external signal to a controlled object, and further includes: A data storage memory 7 is provided to store the contents of the data memory 5 during the calculation of the control program, and can be connected to a maintenance tool 8 for creating and debugging the control program.

Next, the operation of the programmable controller configured as above will be explained with reference to FIGS. 2 to 4.

First, an external signal obtained from the input section 3 is input to the data memory 5.
(input processing 100). Next, the control program is executed using the values stored in the data memory 5, and the results are stored in the data memory 5 (arithmetic processing 101). When the calculation of the control program is completed, the calculation result stored in the data memory 5 is output to an external device via the output unit 6 (output processing 102). The programmable controller performs this input processing 100, arithmetic processing 101. Output processing 102
Execute repeatedly.

Arithmetic processing 101 is executed by a combination of instruction words as shown in FIG. 4, and each instruction word is composed of a type of subroutine for executing bit operations, integral operations, etc. suitable for plant control.

Generally, the input/output edge of data is specified as a parameter necessary to execute this instruction word, but in the present invention, the address number of the instruction word making up the control program and a data storage memory for transferring the operation results are also specified. A table for specifying the address numbers of 7 is provided, and the address number of the instruction word in which the operation result is to be saved and the address number of the data storage memory 7 in which the operation result is to be saved are specified.

On the other hand, as shown in Figure 3, the execution processing function of each instruction word of the programmable controller reads the contents of the table shown in Figure 3 after the function of the instruction word is executed, and if the address of the executed instruction word is specified. In this case, the operation result of the instruction word is transferred to the designated data storage memory 7.

As a result, the contents of the data memory 5, which are the operation results of the instruction words indicated by the address numbers in FIG. 4, remain unchanged even if the instruction words at subsequent addresses are rewritten. 7 is saved.

Since the data storage memory 7 is a separate area from the data memory 5 used for the control program, changing the specifications in the table shown in FIG. 4 will not affect the operation of the control program. Specifying the table and displaying the contents of the data storage memory 7 can be easily achieved using the maintenance tool 8 using the same method as the editing function of the control program and the display function of the data memory 5.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to easily display the contents of any data memory in the middle of an operation without affecting the execution of the operation of the control program, thereby making it possible to efficiently debug the control program. This provides a rational programmable controller that can perform

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a programmable controller according to the present invention, FIG. 2 is a flowchart showing the basic operation of the programmable controller, FIG. 3 is a flowchart showing the data transfer operation in the present invention, and FIG.
The figure is a memory address diagram in the present invention, and FIG. 5 is a configuration diagram of a conventional programmable controller. 1... Programmable controller 2 Program memory 3... Input section 4...
Arithmetic unit 5...data memory 6...
Output section 7...Memory for data storage 8...
Maintenance tool agent Patent attorney Nori Ken Yudo Daishimaru Ken

Claims (1)

[Claims] An input section that inputs external signals, a calculation section that executes calculations of the control program, an output section that outputs calculation results to external equipment,
Consists of a program memory that stores control programs, and a data memory that stores external input signals and calculation results, and performs input processing that stores input data obtained from the input section in the data memory, and calculates the control program stored in the program memory. In a programmable controller that repeatedly executes arithmetic processing and output processing that outputs the calculation results stored in the data memory to an external device via the output unit, it is possible to receive commands from outside to change the contents of the data memory during the calculation of a control program. A programmable controller characterized in that it is provided with a data storage memory that stores data in response to an external command, and is configured to display data externally in response to an external command.