Troubleshooting – narrow down problems
Missing values, blocked controls, virtual PLCs and saving: check common causes and find the relevant guides.
1. Narrow down the problem
First check which project and page are open. Does the problem occur in design mode or play mode? Does it affect one object, one device or the whole project?
- Record the exact message and the steps preceding it.
- Identify whether you are using local simulation, a test server or a real PLC.
- Check one setting at a time and observe the result.
In design mode, open Tools → Check project to inspect the task list. See project validation. Marking a task completed does not fix its cause.
2. Values are missing or stop changing
| Observation | What to check |
|---|---|
| All values from one device are missing | Check the IP address or endpoint first, then the driver, device assignment and server readiness. |
| Only one value is missing | Check the object’s symbol assignment and the signal’s address, data type and read permission. |
| A value stops changing | Change a known source value and compare the display. A last-known value does not prove an active connection. |
| A value is implausible | Compare its data type and register address, plus byte and word order for multi-part values. |
Check connections by driver · Edit the table · Display connection status
3. Controls or writes do not work
Check play mode, the signed-in user and role permissions. For value input, both the table entry and the target device must permit writing. A display alone is not an input control.
If an entered value immediately changes back, check the actual value at the target. Also check whether a virtual PLC or other logic overwrites the same variable.
Test role permissions · Configure value input · Verify writing and readback
4. The virtual PLC behaves unexpectedly
If Apply reports an error, check the indicated location: valid symbol names, data types, write permissions and complete IF/CASE blocks. Execution requires play mode, a started virtual PLC and a satisfied condition.
For unchanged or overwritten values, check symbol assignments, conditions and other blocks writing to the same target. For Pause/Stop, check the shutdown signals assigned in the dialog.
5. Changes are missing after reopening
Check that you reopened the same project file. Apply in a settings dialog and Save project (Ctrl+S) are separate steps. In particular, the virtual PLC program is only stored permanently when the project is saved.
An exported CSV does not replace the project file. When using the table editor, distinguish saving a separate CSV from saving the project.
6. A feature or library is missing
If driver selection is missing, first check whether you are using the demo edition. Importing a CSV does not enable communication drivers. For specialist libraries, check that the package is loaded and activated and the signed-in role permits access.
Demo scope · Load and open libraries · Understand permissions
7. Prepare a support request
Please collect the following details:
- Application version and help ID REF-TROUBLESHOOTING, or the ID of the relevant article.
- The exact error message and steps that reproduce the problem.
- Affected page, object and symbol, plus the selected driver and operating mode.
- Expected behavior, actual behavior and checks already performed.
- If useful, a screenshot of the message or setting, with passwords omitted.
Use the support email below to send these details.