JPH01271802A - Programmable controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a programmer sol controller I~ suitable for constructing a distributed control programmable controller system.
[Close to 1-A.

(Prior art) In a production line in a factory, a plurality of programmable controllers 1 to rollers are connected in a U-shaped manner via a transmission line.
A so-called distributed control type programmable controller [1
- La system is adopted.

In such a programmable controller system, any one of the controllers can be used to
When importing controller data (hereinafter referred to as external variables), the following processing is performed between both controllers.

First of all, in the upper level device that centrally controls the system,
3. Download the external variable table shown in FIG. 4 to each controller.

As shown in Figure 4, this external variable table contains
A partner controller 1 to a controller that is a request partner and one or more variables are stored in pairs.

In this way, once the download of the external variable table for each controller 1 to roller is completed, the controller 1 to roller requesting the external variable and the other controller 1 to roller requesting the external variable are , 70-di1 in Figure 5? - Execute the processes shown in (a) and (b), thereby transmitting external variables from the partner station to the requesting station.

That is, when the external variable request period arrives (step 501 YES), the controller that is the requesting station sets the controller address specified at the beginning of the external variable table as the partner station (step 502), and then writes the external variable table. An external variable request is made by sending this to the partner station (step 503).

Then, after confirming that the external variable request is for its own station (step 511YFS), the controller serving as the other station searches for the variables registered in the received external variable table from within its own station. step 512).

When extraction of all variables registered in the external variable table is completed (step 5'13 YES), the extracted data is edited for transmission and sent back to the requesting station to respond to the external variable request ( Step 514).

Then, controllers 1 to 2, which are the requesting stations, confirm the completion of the response from the other station (step 504 YES).
, move the received external variable data into your own file and use it when needed.

The above steps 503, 504. are performed for all partner stations.
If the process in step 505 is completed (step 506 YES)
), after performing the next cycle setting process (step 507)
, and thereafter waits for the external variable request cycle of the method to arrive (step 501).

(Problem to be Solved by the Invention) However, in such a conventional programmable controller system, each time an external variable request arrives from the requesting station controller, the partner station controller side It is necessary to interrupt the processing being executed, search for and edit the requested data one by one, and perform complex processing such as sending it back to the requesting station, which may cause delays in the processing currently being executed, or There have been problems such as the occurrence of irregular cycles in processes that must be executed at regular intervals.

In addition, since controllers 1 to 1, which are the requesting stations, and controller 1, which is the partner station, are completely asynchronous, for example, the requesting station receives multiple pieces of data that are generated after the control calculation execution cycle is completely completed in the partner station. Even if you want to import the external variables, if the time when the other station accepts the external variable request happens to be in the middle of the control calculation execution cycle, multiple data that have not yet been updated may be requested in the middle of the control calculation execution cycle. There was a problem that the so-called simultaneity of multiple data could not be satisfied.The purpose of the present invention is to prevent frequent external variable requests from the requesting station in this type of programmable controller system. Even if there is a reception (receiving process), there will be no delay in the control calculation processing of the own machine, and even if there are processes that need to be executed at regular intervals, the processing device will No matter what time an external variable request is accepted, the data that satisfies the simultaneity after the control calculation execution cycle is completely completed is always sent to the requesting station without causing any confusion. The purpose of the present invention is to provide a programmable roller that can be returned.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in this invention, in response to the first reception of an external variable table repeatedly sent from another device via a transmission line, , means for internally storing the external variable table and setting an external variable editing request flag;
means for extracting the relevant data of the machine specified in the internally stored external variable table and editing it for transmission in the free time after the end of the seasonal OII calculation execution cycle, and a transmission line. means for transmitting the editing bay data to the corresponding other machine in response to each subsequent reception of the external variable table repeatedly sent from the other machine via the
It is characterized by having the following.

(Function) With such a configuration, the extraction 2 editing process of data corresponding to external variables is performed in the free time at the end of each control calculation execution cycle, so when an external variable request arrives from the requesting station, At this point, I am sending back the edited version.
4T processing is sufficient, and there is no need to interrupt the own machine's processing for a long time. For this reason, there is a significant increase in control processing ()
There is no possibility that errors will occur, or that processes that must be executed at regular intervals will be interrupted.

Furthermore, since the edited performance data returned to the requesting station is always after the end of each control performance execution cycle, data with high simultaneity can always be returned to the requesting station.

(Example) Fig. 1 shows a diagram related to the present invention.
- It is a block diagram schematically showing the electrical hardware configuration of the roller.

As shown in the figure, these programmable
The rollers are centrally controlled by a so-called micro combicoater consisting of a CPU mainly based on a microprocessor and a ROM2, and the RAM3 is divided into a Unab1'gram storage area, an input/output data storage area, a J3. It is designed to realize various functions as a programmable controller while being used as a space and work area.

The transmission unit 4 is equipped with serial/parallel and parallel/serial conversion functions for data transmission,
This transmission section 4 is connected to another programmable controller/roller having a similar configuration via a transmission line (not shown), thereby providing a distributed control type programmable control system 7. is being constructed.

FIG. 2 is a flowchart showing the routine processing performed in connection with the present invention in a control program stored in ROM2, and FIG. 2 is a flowchart showing an interrupt process executed when the interrupt occurs, and the operation of the device of this embodiment will be systematically explained below according to these flowcharts.

As shown in FIG. 2, when the control calculation execution cycle has arrived (step 201 YES), the CPU 1 executes the control calculation according to a predetermined algorithm (step 2o).
2).

As is well known, this control operation performs logical operations based on so-called internal variables imported from the machine itself and external variables imported from other machines, and updates output values based on the results of the calculations. be.

In this way, as soon as one round of control calculations is completed, the state of the external variable editing request flag is referenced, and it is determined from this whether there is an external variable editing request (step 2).
03).

At this time, if it is determined that there is no external variable editing request (NO in step 203), the next cycle setting process is performed (step 205), and then the process waits for the next control calculation execution cycle (NO in step 201).

On the other hand, if it is determined that there is an external variable editing request variable (YES in step 203), data is edited and stored according to an internally stored external variable table as described later (step 204).

In this way, on the condition that the external variable edit request flag is set to Sera I, in the free time after the end of the angle control calculation execution cycle, the machine's own machine specified in the internally stored external variable table, which will be described later, This is because the corresponding data is edited for transmission.

On the other hand, if an external variable table is repeatedly sent from another device via the 1-m transmission line, this programmable controller performs the external variable sending process shown in FIG. 3 by interrupt.

In other words, since the external variable edit request flag has been cleared by a predetermined initial process, when receiving the external variable table that is repeatedly sent from another device via the transmission line for the first time, it is set as "no external variable edit request". A determination is made (step 301 NO>).

Therefore, when receiving an external variable table repeatedly sent from another device via a transmission line for the first time, the external variable table is immediately stored in its own RAM (step 302>, and the external variable edit request flag is set. A process (step 303) is performed.

After that, only for the first reception, as before, after vr1 recognizes that the external variable request is for its own station (step 304 YES), it searches for and extracts the variables registered in the external variable table. When the same processing is completed for all variables (step 306 YES), the extracted data is forwarded to 1liii and processing is performed without returning a response to the requesting station (step 307). , returns to the routine processing shown in FIG.

Therefore, when receiving the external variable table that is repeatedly sent from the machine via the transmission line for the first time, the processing that was being executed in the machine until then is interrupted for a relatively long time, just like in conventional equipment. .

In this way, after the external variable editing request flag is set to red 1 (step 3C), as shown in flowcharts 1/-1 to 1 in FIG. Each time a control calculation execution cycle ends (
Step 202), the process of editing and storing data according to the external variable table is performed periodically (
Step 204).

After this, as shown in FIG. 3, when receiving the external variable table that is repeatedly sent from other devices via the transmission line (step 301 YES),
It is only necessary to perform the process (step 308) of returning the edited data created in step 204 to the requesting station, and there is no complicated process such as searching and extracting the variables registered in the external variable table as in the case of initial reception. There is no need to perform the time-consuming process (step 305),
As a result, the processing interruption time of the own machine can be made extremely short.

Therefore, according to the device of this embodiment, when receiving the external variable table repeatedly sent from other devices via the transmission line for the first time, the processing of the own device is interrupted for a slightly long time, but the next time Regarding the processing interruption time for subsequent reception, it is only a short time to send the edited data back to the requesting station, which may cause a significant delay in the control calculations of the own machine, or may be interrupted at regular intervals. There is no longer a cycle of processing that must be performed.

Furthermore, since the data returned to the requesting station is extracted and processed after the end of the angular control calculation execution cycle, the data is highly consistent for each control calculation execution cycle, and is compatible with an asynchronous transmission system. However, the requesting side can always obtain data with high simultaneity.

In addition, in the above embodiment, as shown in FIG. 3, only at the first reception, not only is the external variable table stored and the external variable edit request flag set, but also the data registered in the external variable table is set. We have also performed the process of searching and extracting the variables that are present, but when receiving data for the first time, we only need to store the external variable table in our own RAM and set the external variable edit request flag. If the edited data is sent back and this four-way method is used, the processing interruption time can be shortened even when the data is received for the first time.

[Effects of the Invention] As is clear from the above explanation, according to the programmable controller according to the present invention, even when constructing a distributed control type programmable controller system, each controller Data can be transferred with high degree of simultaneity between the respective conveyor rollers without causing a delay in control calculation processing, etc., or disrupting processes that must be executed at regular intervals.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a diagram showing an embodiment of the programmable controller according to the present invention. Flow A-1 to Figure 3 show the routine processing of the rollers.
FIG. 4 is a memory map showing the structure of the external variable table, and FIG. 5 shows the external variable collection processing and external variable editing processing in a3 of the conventional Programmer Sol 21-1 Herola J-Flow 17- It is. 1...CPU 2...ROM 3...RAM 4...Transmission section

Claims (1)

[Claims] (1) means for internally storing the external variable table and setting an external variable edit request flag in response to the first reception of an external variable table repeatedly sent from another device via a transmission line; On the condition that the external variable edit request flag is set, in the free time after the end of each control calculation execution cycle, the relevant data of the own machine specified in the internally stored external variable table is extracted and used for transmission. and means for transmitting the edited data to the corresponding other machine in response to each subsequent reception of the external variable table repeatedly sent from the other machine via the transmission line. A programmable controller characterized by