KR19990021175A - Implementation Method of SFC Program for Sequence Process Control - Google Patents

Abstract

The disclosed invention relates to a method of implementing a sequential function chart (SFC) program for sequential process control. Particularly, in a window environment, an application program is divided into steps and transitions using icons for each function, and thus the application program is efficiently developed on a screen. Editing can be performed. The present invention can be applied to various sequence process control by generating SFC code when editing is completed and changing the program to interpret SFC code, so that it is versatile and satisfies the conditions defined by the International Electrotechnical Commission (IEC). This can be easily accommodated for language-based applications.

Description

Implementation Method of SFC Program for Sequence Process Control

The present invention relates to a method of implementing an SFC program for controlling a sequence process. In particular, an application program is developed in a flowchart form using a function-specific icon in a window environment in steps and transitions, and the generated SFC code is interpreted even when hardware is changed. The present invention relates to a method of implementing an SFC program for sequence process control that can be applied by changing a program.

In general, a sequence process control program for controlling a continuous process has generally used a programmable logic controller (PLC) that operates under the control of a controller in consideration of the use environment of the process. Therefore, different programmatic controllers (PLCs) must be programmed separately according to the usage environment, and there is a problem that cannot be applied to other sequence process control.

In consideration of this, the International Electrotechnical Commission (IEC) has established standards for the SFC (Sequential Function Chart) as a sequence control program that can be applied universally regardless of the use environment. Therefore, an SFC program that can be used for sequence process control while satisfying prescribed conditions is proposed. As such, most of the SFC programs satisfying the prescribed conditions are operating programs in which the editing work is performed under the DOS environment, which is not only limited in convenience but also takes a long time. In addition, in recent years, SFC programs that operate under the Windows environment have been developed. However, as they are applied only to a specific use environment, it is difficult to flexibly cope with hardware changes.

An object of the present invention is to deploy an application program in the form of a flowchart using icons for each function in a windowing environment, and use the SFC code and analysis program generated when editing is completed, so that it can be applied as a sequence process control program even if hardware is changed. The present invention provides a method of implementing an SFC program for controlling a sequence process.

1 is a screen showing an editing operation for an SFC program according to the present invention;

2 is a view showing an icon and a function used as a work tool in the present invention,

Figure 3a is a screen for setting the language and name inside the step in the present invention,

3b is a screen for setting a transition condition in the present invention;

4 is a view showing an embodiment of completing the editing operation and the SFC code according to the present invention;

5A is a view showing an example of an editing operation for a serial branch in the present invention,

Figure 5b is a view showing an example of the editing operation for the parallel branch in the present invention.

Explanation of symbols for main parts of the drawings

10: Edit screen 11: Icon box

20: Step setting screen 21: Name input field

30: Transition setting screen 31: Transition condition input column

An object of the present invention as described above is an SFC program for developing an application that runs hardware to a step that binds one or more drive programs for controlling the step-by-step drive operation and a transition that presents a condition satisfying a transition between the steps. Setting a name and a language for identifying the driving program belonging to the step for the driving programs for the application program in the edit screen under the window environment; Creating a transition setting the initial step for driving the program and the dichotomous condition for transitioning to the next step under the activation of the initial step by clicking the icons for each function displayed on the editing screen; Branching steps and transitions serially or in parallel using the function-specific icon according to the execution procedure of the application program; And generating the SFC code when the expansion operation of the step and the transition is completed.

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

In the sequential process control, since the work process is continuous according to the order of the steps, the SFC program needs to program the process by the process order to control the lower step at the best step. The SFC program proposed in the present invention is a representation of the development of the execution order of the work process, and the execution and transition of the detailed operation at each step are performed by a separate function block diagram or structured character. It is driven by language (Structure Text) and so on, and the SFC program that supports it is controlled by the execution process order of the work process.

The present invention is based on the premise that an editing operation is performed on an SFC program in a window environment. In the present invention, the driving program is bundled into steps according to the execution order for the application program related to the control process, and the transition operation of each step is determined by the set transition condition. In this way, the relationship between the step and the transition is displayed in a flowchart form using icons for each function arranged in the icon box 11 in the edit screen 10 of FIG. 1.

Icons I1 to I8 of the icon box 11 are work tools for displaying the step S and the transition T according to the development rule. As shown in FIG. use. Specifically, editing the first icon I1 for editing the initial step, the second icon I2 for editing the intermediate step, the third icon I3 for displaying the transition, and the ending step. The fourth icon I4 for the purpose, the fifth icon I5 for indicating the disconnection branch line branched to disconnection, the sixth icon I6 for indicating the parallel branch line branching in parallel, and the left branch line for disconnection Or a seventh icon (I7) indicating a branching link line by checking whether it is a parallel branch line and an eighth icon (I8) indicating a convergence line that converges by checking whether a left branch line is a branch line or a parallel branch line. Separate.

3A is a screen for setting a language and a name inside a step according to the present invention, and sets a language of each program for a step including one or more driving programs and gives a name to the program. That is, the step setting screen 20 is called up on the edit screen 10, and then one of the function block diagram and the structured text language is selected and driven in the name input box 21. Enter a name for the program.

3B is a screen for setting a transition condition according to the present invention, which is a screen for assigning a condition for determining a transition operation between steps. After calling the transition setting screen 30 on the edit screen 10, the transition condition input box ( Enter the conditional expression in 31). This conditional expression selects one of the boolean values (TRUE or FALSE) or whether it is greater or less than a specific value such as zero. The transition represents an execution processing condition. When the condition is satisfied, the next connected step is activated.

The SFC program of the present invention generates the SFC code for the edited program by the SFC code generator when the editing operation is completed. One such embodiment is shown in FIG. This SFC code can be used to change the analysis program depending on the hardware.

A process of branching and developing in series or parallel using the icons I1 to I8 will be described with reference to FIG. 5.

5A illustrates an example of an editing operation for a serial branch in the present invention, in which two steps are not directly connected to each other and a transition condition must be set between the steps and the steps, and two transitions are not directly connected to the step. Should be separated by. The transition operation of the steps connected in series in the longitudinal direction becomes the next connected step when the upper step satisfies the transition condition in the active state.

When the step is branched in series in the transverse direction in FIG. 5A, the step connected to a satisfying condition among two or more transition conditions connected to the next step in the upper step S1 is activated, and becomes active. For example, if the transition condition T1 is satisfied, step S1 = step S2 = step S3 is activated, and if the transition condition T4 is satisfied, step S1 = step S4 = step In the order of (S3), the state is activated, and when the transition condition T5 is satisfied, the state is activated in the order of Step S1 = Step S5 = Step S3. If the transition conditions are satisfied at the same time, the transition condition on the left has priority.

FIG. 5B is a diagram illustrating an example of an editing operation for a parallel branch in the present invention. When a branch is parallel in the horizontal direction, all steps under the transition condition are activated when the next connected transition condition is satisfied while the upper step is activated. It becomes a state. The evolution of each branch is the same as the serial branch and there are active steps as many branches. In the case of merging in parallel branches, if the last step of each branch is all active, the next connected step becomes active if the transition condition is satisfied. In FIG. 5B, when the transition condition T1 is satisfied while the step S1 is in an activated state, the steps S2, S6, and S8 are activated and the step S1 is deactivated. When the transition condition T4 is satisfied while the steps S4, S7 and S8 are active, the step S5 is activated and the steps S4, S7 and S8 are inactivated.

As described above, the present invention divides an application program into steps and transitions by using icons for each function in a window environment, so that the editing operation can be efficiently performed on the screen. The present invention can be applied to various sequence process control by generating SFC code when editing is completed and changing the program to interpret SFC code, so that it is versatile and satisfies the conditions defined by the International Electrotechnical Commission (IEC). This can be easily accommodated for language-based applications.

Claims (4)

In an SFC program that develops a step that binds one or more drive programs that control a step-by-step drive operation to an application operating hardware and a transition that presents a condition satisfying a transition between the steps, Setting a name and a language for identifying the driving program belonging to the step for the driving programs for the application program in the edit screen under the window environment; Creating a transition setting the initial step for driving the program and the dichotomous condition for transitioning to the next step under the activation of the initial step by clicking the icons for each function displayed on the editing screen; Branching steps and transitions serially or in parallel using the function-specific icon according to the execution procedure of the application program; And And generating an SFC code when the expansion operation of the step and the transition is completed. The method of claim 1, wherein the icon for each function comprises a first icon for editing an initial step, a second icon for editing an intermediate step, a third icon for displaying a transition, and a second step for editing an end step. 4 icons, a fifth icon indicating a disconnection branch line branching into a single line, a sixth icon indicating a parallel branch line branching in parallel, and a linking branching by checking whether the left side is a disconnection branch line or a parallel branch line And a seventh icon indicating a diverging line and an eighth icon indicating a convergent line which converges by checking whether a left line is a single branch line or a parallel branch line. The method as claimed in claim 1, wherein the step of creating the transition sets a condition for selecting any one of TRUE and FALSE. The method as claimed in claim 1, wherein the step of creating the transition sets a condition for selecting whether the transition is larger or smaller than a specific value.