Causes

A PLC card of the Siemens PLC station type ET200xxx has been identified as a non-valid rack, since the properties Bus coupler / head station and CPU were not assigned in accordance with the rules.

Solution

1. Locate the PLC card in the schematic using the Go to (graphic) functionality from the popup menu in the Message management dialog.
2. Launch the property dialog of the PLC card.
3. Bring the PLC structure data tab to the front.
4. If the PLC box is to represent a bus coupler and / or CPU, ensure that the properties Bus coupler / head station and / or CPU are activated. Additionally enter the desired value into the Rack field.
5. Click [OK].
6. Then start a new check run.