PLC logic changes silently (eliminated from PLC Designer V3.6)

Eliminated from:
PLC Designer V3.6

Behaviour of the new version:

When executing the below-described actions, the PLC logic does not change anymore.

What happens?
The programmed PLC logic changes. The PLC Designer silently adds, deletes or relocates negations and edge detections on function blocks within the network.

When does the problem occur?
The above-described response may occur in the programming languages ladder diagram (LD) and function block diagram (FBD), if either

the compiler version of the PLC project is updated from a higher version to version V3.5.2.23 or lower (menu item Project>Project Settings>Compile Options)

if the project is saved in the File>Save as ... dialog using a file type "Project files (PLC Designer V3.3.2)" or lower in an older project format

if a PLC Designer export file is imported into a PLC project using a compiler version lower than V3.5.2.23 coming from a PLC project using a higher compiler version.

Which products are concerned?
PLC Designer from V3.5

Possible diagnostics:
None

Short-term measures/recommendations:

Do not update the compiler version of your project from a higher version to version V3.5.2.23 or lower.
When saving your project, do not select file types using a PLC Designer version lower than or equal to V3.3.2.
Only import export files coming from PLC projects using the same or a lower compiler version.

Evaluation:
In the above-described cases, the PLC logic may change silently. The function restriction concerns the programming languages ladder diagram and function block diagram.

The function restriction does not concern the typical case of compiler version updates from lower to higher versions.

The function restriction neither occurs when saving the PLC project in the PLC Designer format in which it is opened.

URL for linking this AKB article: /en-de/go/akb/201303381/1/