Variables that will be exchanged between the controller and (multiple) HMI devices using the transparent Machine Expert protocol must be published in the controller using the Symbol configuration. They will then be available as EcoStruxure Machine Expert variables in Vijeo-Designer.
Defining a Symbol Configuration
In order to get the symbol configuration functionality available, add the symbol configuration object to the application in the Tools tree as described in the Opening the Symbol Configuration paragraph. This IECVarAccess.library is automatically added to the Library Manager.
You can define the variables to be exported as symbols in the symbol configuration editor or via pragmas (attribute symbol), which are to be added at the declaration of the variables.
NOTE: Variables of a global variable list (GVL) will only be available in the symbol configuration if at least one of them is used in the programming code.
NOTE: Constants are available in the Symbol configuration if the option Replace constants in the Project Settings > Compile options dialog box is deactivated. For particular constants, you can configure the option explicitly by using the attributes {attribute 'const_replaced'} and {attribute 'const_non_replaced'}.
However, in any case the following is true: Constants in a global variable list (GVL) or in another POU are only available in the Symbol configuration, if the GVL or POU is used in the program code, or if the compiler option Link always is activated in the View > Properties > Build dialog box of the GVL or POU.
Another possibility is provided by the SFC editor: You can define the implicitly created element flags in the element properties for export to the symbol configuration.
The name of a symbol created by the symbol configuration is composed according to the following syntax:
<application name>.<POU name>.<variable name>
Examples:
MyApplication.PLC_PRG.a
MyApplication.GVL.a
For accessing the variable, define the symbol name completely.
Opening the Symbol Configuration
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Step |
Action |
|---|---|
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1 |
Select the Application node in the Tools tree, click the green plus button, and select the command Add other objects > Symbol configuration.... Result: The Add Symbol configuration dialog box will be displayed. |
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2 |
In the Add Symbol configuration dialog box, optionally configure settings like whether to include comments or not. The settings can be modified later in the Symbol configuration editor. |
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3 |
Click the Add button. Result: A Symbol configuration node is created under the Application node in the Tools tree. The Symbol configuration is displayed on the right-hand side. |
NOTE: Only one symbol configuration node can be created per device.
For details on the variables interchange between the controller and HMI part, refer to the chapter EcoStruxure Machine Expert Controller-HMI Data Exchange.
