Cause
One and the same value was entered at the Safety address: Source property at at least two PLC boxes that are safety-relevant in the project.
Solution
- Locate the PLC boxes in the schematic by using the functionalities Go to (graphic) and Go to 2nd coordinate, which the popup menu of the Message management dialog offers you.
- Open the property dialog of each PLC box one after the other.
- Bring the first tab to the front.
- Enter a unique value in the table of properties in the Safety address: Source field.
- Click [OK].
- If required, start a new check run.