If you plan to modify the controller while online, see Plan for Test Edits for information about the parameters available in the Advanced settings.
On the Advanced tab of the controller properties, make sure that the Match Project to Controller checkbox is cleared.
IMPORTANT:
Do not select the Match Project to Controller parameter for a redundant controller. If you select Match Project to Controller, you cannot go online with, download to, or upload from the new primary controller after a switchover.
The serial number of the new primary controller is not the same as the serial number of the old primary controller and the project cannot be matched to the newly switched to controller.
