Performing an Online Change
CODESYS automatically offers you an online change if you login with an application that is already present on the controller, but has been changed since the last download in the programming system. For this operation, only the modified parts are downloaded again to the controller. A running program on the controller is not stopped during the online change.
In the Online Change Memory Reserve view, you can configure memory reserves for the online change for function blocks of a project. In this way, instance variables do not have to be moved to the memory after changes are made to a function block for an online change.
Important
When carrying out the online change, pay attention to the notes in the description of the Online Change command.
Executing the online change when logging in
Requirement: The connection settings of the controller are correctly set. The applications in the project and on the controller are identical. The project on the controller is running. The application is logged out.
Change your application.
Click .
A dialog appears with the information that the application has been changed since the last download.
Click the Details button.
Check the details on the Application information tab.
If you have not generated any code since the last change, the command Application is not up to date. Generate code now? appears at the bottom edge of the dialog. In this case click this command.
You are shown a comparison view of the objects (objects marked red are different).
Close the dialog.
Select the option Login with Online Change and click OK.
The change is loaded to the controller. The running program on the controller is not stopped while doing this. The application is logged in.
Execute online change in the logged-in state (online mode)
Requirement: The connection settings of the controller are correctly set. The applications in the project and on the controller are identical. The project on the controller is running. The application is logged in.
Select an object in the device tree. It is best to select a POU or a GVL here.
Click .
The object opens in the editor.
Change the object. For example, you can declare a new variable or change a value assignment here.
Click .
A query will appear, asking whether you really want to execute the online change.
Click Yes to confirm the dialog.
The change is loaded to the controller.