In handling Descriptors with different OPC UA FxVersions, the following rules apply:
- Engineering tools shall document the supported OPC UA FxVersion.
- Engineering tools that are able to export or import Descriptors of a specific OPC UA FxVersion shall also be able to export or import Descriptors of a previous OPC UA FxVersion (backward compatibility).
- Engineering tools that are able to import Descriptors of a specific OPC UA FxVersion shall be able to import Descriptors of a newer OPC UA FxVersion in a best-effort way, i.e. features that are available in the older OPC UA FxVersion can be imported, while newer features shall be ignored. Ignored features should be logged.