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Resetting Applications

Resetting the application stops the program and resets the variables to their initialization values. Depending on the type of reset, retain variables and persistent variables are also reset.

  • Reset Warm: All variables are reset, except RETAIN and PERSISTENT variables.

  • Reset Cold: All variables are reset, except PERSISTENT variables.

  • Reset Origin: All variables are reset.

  • Reset Origin Device: All variables are reset and all applications are deleted.

The following sample program and statements clarify the functionality of the various resets.

Example 38. Sample program

Declaration

VAR
        iVar: INT := 0;
END_VAR
VAR RETAIN
        iVarRetain: INT :=0;
END_VAR
VAR PERSISTENT
        iVarPersistent : INT:= 0;
END_VAR

Implementation

iVar := 100;
iVarRetain := 200;
iVarPersistent :=300;

  1. Insert the Persistent Variables object below the application and open it in the editor.

  2. Execute the Build → Build command.

  3. Execute the Declare → Add All Instance Paths command.

    The instance path of the persistent variables is inserted.

  4. Download the application to the controller.



Executing a Reset Warm, Reset Cold, and Reset Origin

Requirement: The sample program runs on the controller.

  1. Click Online → Login to switch to online mode.

  2. Monitor the variables iVar, iVarRetain, and iVarPersistent.

  3. In the Online menu, click Reset Warm.

    You are prompted whether you really want to execute the command.

  4. Click Yes to confirm the dialog.

    The application is reset. The iVar variable is set to the initialization value 0. Both of the other variables retain their values.

  5. In the Online menu, click Reset Cold.

    You are prompted whether you really want to execute the command.

  6. Click Yes to confirm the dialog.

    The application is reset. The iVar and iVarRetain variables are set to the initialization value 0. The iVarPersistent variable retains its value.

  7. In the Online menu, click Reset Origin.

    You are prompted whether you really want to execute the command.

  8. Click Yes to confirm the dialog.

    The application is reset. All variables are reset to their initialization values.

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