JPH0319002A - Internal processing method for programmable controller - Google Patents

Abstract

PURPOSE:To prevent the continuation of the same processing by discriminating the contents of the processing requests received right before execution of plural data processings respectively and requesting other processings based on the discriminated contents of the processing requests. CONSTITUTION:A programmable controller contains an input/output device 2 which carries out plural data processings for external equipments and a processor 1 which controls the data processings in accordance with the data processing state of the device 2. When an internal processing of the programmable controller is carried out, the data processing which is carried out right before the requests are produced for those data processings is discriminated. Based on this discrimination result, the data processing to be carried out first after said discrimination operation is decided. Thus the same processing request is never continuously produced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an internal processing method of a programmable controller, and more specifically, to a method for processing multiple data such as input/output data processing and message data processing performed by an input/output device. The present invention relates to an internal processing method of a programmable controller.

(Prior art) Programmable controller (hereinafter referred to as PC) -
The internal configuration mainly consists of input/output devices for connecting various external devices and performing predetermined processing on input data from these devices, or for processing data output to external devices, and these input/output devices. It consists of a processor that controls the processing of data input/output at a position and the data exchange, and outputs data to a motor etc. as an external device based on input data input from an external device such as a sensor. And this motor? 1iIJ control, etc.
It controls the entire system consisting of connected external devices.

Furthermore, it is possible to connect a personal computer or an external storage device such as a floppy disk as an external device, making it possible to configure a more diverse and flexible system using a PC. As a PC system, for example, processing in a production factory, etc.

Monitoring the assembling process, transportation line system, and logistics during the process? ! IIJ control systems and PC systems are now being used in a wide range of fields.

FIG. 2 is a schematic block diagram showing an example of an internal processing configuration in a PC.

In the figure, a processor 1 controls the entire PC system according to a so-called user program of the PC system, and also controls data exchange and data processing with input/output devices. Reference numeral 2 denotes an input/output device that exchanges data with connected external devices and processes these data. Note that here, the input/output device 2 is an input device to which an input-only external device is connected.

This indicates either an output device that connects an external device exclusively for output, or an input/output device that serves both purposes.

A PC system mainly composed of the processor 1 and the input/output device 2 as described above has a plurality of input/output devices corresponding to each external device to be connected, and these input/output devices and the processor Control signals and data are generally exchanged between them via a common bus. Therefore, as shown in FIG. 2, when each input/output device 2 finishes processing data for its own dish, it transmits this to the processor 1 using an interrupt 4, and based on this, the processor 1 uses the input/output device that generated the interrupt. A new processing request 3 is output to the device or other input/output device.

Interruption 4 also occurs when there is a so-called message data processing request requesting execution of a predetermined process from, for example, a personal combination connected as an external device.

FIG. 3 is a flowchart showing a conventional example of the above-mentioned internal processing procedure.

Since no new processing requests can be made while the input/output devices are operating to perform the above-mentioned various data processing and data exchange, it is checked in step S31 whether or not the input/output devices are stopped, for example, for each of the input/output devices. If the input/output device is stopped, a request is made to input/output data processing from the input/output device determined to be stopped in step S32, and the process advances to step 833. If it is determined that the message data processing is not stopped, the process proceeds to step S33, and it is determined whether or not the input/output device requesting message data processing is stopped, in the same manner as in step S31. Here, if the determination is affirmative, the process requests the input/output device to process the message data and returns to step 831; if the determination is positive, the process returns directly to step 831.

Here, if an interrupt 4 indicating, for example, that the process has ended occurs at the timing of step 85 or step S6 in the figure, the process is executed from the next process, that is, step 531g or step S32, D). Especially fjru.

[The problem that the invention attempts to solve]

Incidentally, as input/output data processing is performed cyclically in each input/output device, interrupt 4 indicating the end of the processing is almost always entered periodically.
In such a case, for example, if most of the interrupts 4 occur at the timing of step S5, the processing of step 832,
In other words, only input/output data processing requests are carried out, and message data processing may not be carried out at all.

Furthermore, if most of the interrupts 4 occur at the timing of step S6, the opposite is true, and the input/output data processing will be delayed.

The present invention aims to solve the above-mentioned problems in the conventional internal processing. Before making a processing request for each, it is determined whether the most recent processing request has been received, and other processing is requested based on this determination, thereby preventing the same processing request from occurring consecutively. PC to avoid delays in executing certain processes.
The purpose is to provide an internal processing method for

[Means for solving lines]

In order to achieve the above-mentioned object, the present invention has an input/output device to which an external device is connected and performs a plurality of data processing related to the external device, and the input/output device is connected to an external device and has an input/output device that processes a plurality of data regarding the external device. In an internal processing method of a programmable controller that controls the execution of the plurality of data processes by the device, before requesting each of the plurality of data processes, the most recently performed data processing is determined, and the data processing is executed most recently. The method is characterized in that, based on the determination, the first data processing to be performed after the determination is determined.

[Effect]

In the internal processing method of a PC that controls multiple data processes executed in an input/output device, before making a processing request for each of the multiple data processes, it is necessary to check 7J) which processing request was made most recently. By making a determination and requesting other processing based on this determination, it is possible to prevent the same processing request from occurring consecutively.

〔Example〕

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

FIG. 1 is a flowchart of an internal processing procedure by a processor showing one embodiment of the present invention.

The processing procedure shown in the same figure differs from the conventional example shown in FIG. The process of steps 812 and 315 is performed to determine whether the processing request is a processing request to be performed in the next step, for example, by referring to a flag.

As a result, if it is determined in step 812 that input/output data processing was performed last time, message data processing is requested in step 816, and if input/output data processing was not performed last time, input/output data processing is performed in step S13. Perform data processing.

Similarly, in step 815, it is determined whether or not the previous process was message data processing, and depending on this determination, step 8.
13 or step S16.

Note that the process for determining the data processing that was performed last time is not necessarily performed as in the above embodiment (it is not necessary to perform this individually before each data processing request, for example, by referring to multiple flags corresponding to each process). By doing so, the most recently performed process may be determined once, and the next process request may be determined based on this determination.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, multiple data processes executed in an input/output device are
In the internal processing method of a PC, before making a request for each of multiple data processes, it determines what the most recent processing request was, and requests other processing based on this determination. By doing this, it is possible to prevent the same processing from occurring consecutively.

As a result, there are no cases where only specific processing is performed, and multiple data processing performed on the input/output device can be performed in a predetermined order, and execution of specific processing can be prevented from being delayed. It becomes possible.

[Brief explanation of drawings]

Fig. 1 is a flowchart showing the internal processing of a PC according to an embodiment of the present invention, Fig. 2 is a schematic block diagram showing the configuration of the internal processing of the PC, and Fig. 3 shows a conventional example of the internal processing of the PC. FIG.

Claims (1)

[Scope of Claims] 1) An input/output device to which an external device is connected and which processes a plurality of data regarding the external device; In an internal processing method of a programmable controller that controls the execution of data processing, before making a request for each of the plurality of data processings, the most recently performed data processing is determined, and the data processing is performed based on the determination. An internal processing method for a programmable controller, characterized by determining the first data processing to be performed after determination.