GRAFCET diagrams can be created on an existing page or on a new page. This section describes how a GRAFCET diagram can be created on a new page. The procedure for creating GRAFCET diagrams on existing pages is similar.
Preconditions:
- You have opened a project.
- You have added the symbol library OS_SYM_ESS.slk to the project. (This setting is carried out this via the Options > Settings > Projects > "Project name" > Management > Symbol libraries menu items.)
- In the project settings you have specified the special symbol that is used for the placing of the property texts in operational sequence sheets (e.g., OS3 for GRAFCET diagrams).
- You have inserted functions or devices in the project and have entered on those the required values for the properties Function text, State [1] to State [10], etc.
Notes:
- If you create a GRAFCET diagram, the Functional placing with symbol graphic project setting must be deactivated.
- The State [10] property has been set aside, by default, for the input of variables for GRAFCET diagrams. If you use the special symbol OS3, the value of the State [10] property is placed as the variable text.
Create project page for the GRAFCET diagram
- Create a new project page using the Page > New menu items.
- Select the entry "Overview (I)" in the New page dialog in the Page type field, and enter a descriptive text for the project page in the Page description field.
- In the table in the Grid field, enter the value "3 mm".
- Click [OK].
A new project page is generated. If the grid settings and the form used match, the grid points will be in the center of the table rows defined in the form. This facilitates the correct placing of devices and process sequences.
Create table of variables
The table header of the table of variables is created by means of a macro. You can insert a single table row by placing the property texts from the device navigator.
- Open the project page for the operational sequence sheet, e.g., by double-clicking the project page in the page navigator.
- Select the Insert / Window macro / symbol macro menu item.
- Select the "Window macro (*.ema)" entry from the File type drop-down list of the Select macro dialog. The list only displays the existing window macros.
- Navigate to the macro directory OS_ESS, and select the Table_GRAFCET.ema macro there.
- Click [Open] and then place the macro with the table header at the required position in the diagram.
- Select the menu item Project data > Devices > Navigator.
- Mark a function in the device navigator and select the Place functional > With symbol graphic popup menu items. The special symbol defined in the project settings hangs on the cursor. If you use the special symbol OS3, a table row with the property texts of the function will be displayed (i.e., the value of the State [10] property).
- Place the graphic (the table row) at the required position in the diagram.
- Repeat the above steps for the other devices that you want to place in the table of variables.
Draw process sequences
You use graphical elements (e.g., polylines) to draw process sequences. EPLAN provides support to enable you to insert some special elements of operational sequence sheets faster. Arrows, signal points, AND and OR conditions, GRAFCET steps, GRAFCET actions, and GRAFCET transitions can be drawn into the respective operational sequence sheet by means of the corresponding menu items via the Insert > Operational sequence sheet menu path or the Operational sequence sheet toolbar.
- If you want to draw a polyline, select the Insert > Graphic > Polyline menu items. (You can draw rectangles, circles, etc. using the other submenu items in the Graphic menu.)
- Specify the points of the polyline consecutively, and click with the left mouse button each of the points to place them.
- Exit the action using the [Space bar] or the Complete polyline popup menu item.
- Select the Insert > Operational sequence sheet > GRAFCET > Step menu items to insert a step. (You can insert other GRAFCET elements using the submenu items Step with transition, Action, Action with connection, and Transition.) The step is hanging on the cursor.
- Select the desired variant of the step, such as a starting step, by pressing the [Tab] key several times.
- Place the step in the operational sequence sheet. Then the symbol hangs again on the cursor, and you can place another step.
- Exit the action using Edit > Cancel action or [Esc].
- Repeat the above steps for the other GRAFCET elements that you want to place in the operational sequence sheet.
Tips:
- You can insert special elements for operational sequence sheets (e.g., a forward slash, miscellaneous signaling elements, etc.) as window macros from the macro directory OS_ESS. In addition, using the Arrows.ema macro you can also insert prefabricated arrows in a GRAFCET diagram.
- The asterisk (*) in the GRAFCET elements inserted shows you that you can enter in this space texts such as step names, transition names or conditions or an action identifier. The different objects of a GRAFCET element are combined into a group. In order to enter a single text directly without undoing the grouping, keep the [SHIFT] key pressed and then open the Properties - Text dialog by clicking the respective asterisk.
- Using the C variant of the special symbol OS3, you can place only the displayed DT of the selected device. The D variant allows you to place only the variable of the highlighted device. This way you can insert the device tags or variables also as texts in the sequential control of a GRAFCET diagram.
See also