Cause
You used a non-permitted character when entering the device tag.
Solution
Possibility 1
Select the menu items Utilities > Master data > Identifier and check the Suggested identifiers dialog to see which letter was entered for the selected function definition. When entering the DT, use the identifier characters you see here.
Possibility 2
If the DT still shows the incorrect character, you have to create a corresponding identifier assignment. To do this, select the menu items Utilities > Master data > Identifier and select the popup menu item New in the Suggested identifiers dialog. Create a name for the new identifier set and enter the identifier for the corresponding function.
After this, it is essential that you synchronize the master data of the project (Utilities > Master data > Synchronize current project).
Then start a new check run.
See also