Creating a “Hello World” Application

  1. In the tree view right-click on App node and add a new object.

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  2. In the following dialog select C_Code_App and click Add object.

    Select the compiler to be used for the new C/C++ application and click Add.

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  3. In the following dialog select POU and click Add object.

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  4. Select the type for the POU object and click Open.

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  5. Enter a parameter and variable declaration.

  6. Right-click at the desired code position and select Input Assistant in order to define the data type:

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  7. Then, click Apply to update the interface. As an alternative the interface can be displayed tabularly. Tabular view is a comfortable way to edit parameters:

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  8. On the C_Code_App tab open the Compiler options tab. Select a compiler and configure compiler settings for the C/C++ application. These settings enable the compiler to interprete and process the source files listed on the C-Code tab.

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  9. Open the C-Code tab. The following files are listed:

    • C_Code_App.c: Implementation of POU.
    • C_Code_App.h: C/C++ Interface of POU.
    • C_Code_App_Init.c: Initialization of POU variables and parameters.
    • C_Code_App_Shell.c: Main module.
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    Note

    Double-click the Folder icon to open the directory in Windows Explorer.

  10. To edit the POU implementation double-click or right-click a file and select Open…). The *.c and *.h files are opened in your operating system’s default editor.

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  11. Save your settings and click Compile on the right side of the screen. The object files are generated from source code. Compilation errors are reported within a message window. Details on the error can be found in the compiler.log file.

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  12. Save your project. In the tree view double-click Application. CODESYS is started with C/C++ interface. From the C_Code_App node an external library is generated. This library can be found in CODESYS 2.3 in the Library Manager.

  13. Call the C/C++ code POU from your IEC application.

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    Note

    In order to lookup C/C++ POUs, press F2 and open section Standard Functions / Standard Function Blocks .

  14. Build the project via Project ‣ Build: C/C++ application parts are linked together with IEC application.

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    Application is ready for download.