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    Declaring VAR PERSISTENT Variables

    Below you will declare persistent variables in a persistent variable list and in a POU.

    Requirement: A project is opened and contains a program POU. You have selected the option for the textual view in the Declaration Editor category of the options (Tools → Options menu command).

    1. Click Project → Add Object to add the Persistent Variables object to the application object.

      CODESYS adds the persistent variable list _cds_icon_gvl_persistence.png PersistentVars below the application object in the device tree, and the editor opens.

    2. In the editor, enter a variable declaration, for example ivarpersist1 : INT; between VAR_GLOBAL PERSISTENT RETAIN and END_VAR.

    3. Double-click the POU in the device tree.

      The editor of the POU opens.

    4. Specify the following declaration in the declaration part:

      VAR PERSISTENT RETAIN

      ivarpersist2 : INT;

      END_VAR

    5. Click Build → Build.

      The message view opens. If CODESYS has compiled the application without errors, then close the message window and continue with the next step. Otherwise, correct the error(s) and click Build → Build.

    6. Set the focus in the PersistentVars editor. Click Declarations → Add All Instance Paths.

      CODESYS adds the persistent variable from the persistent variable list PersistentVars to the POU:

      // Instance path of the persistent variables created

      POU.IVARPERSIST2 : INT