Resolve Redundant PCS 7 V9.0 SP3 OS Restarts After a TLGRT Exception

For the reported PCS 7 V9.0 SP3 system, Siemens Support reportedly identified Update Collection 4 (UC04) as the fix for redundant OS restarts following an invalid TLGRT self-diagnostic value from Machine.Software.WinCC.TagLoggingServer. Treat this as a case-specific resolution: confirm the WinCC component update and supported UC path for the affected installation, then verify redundancy, Runtime stability, and Tag Logging after maintenance.

Symptom and reported resolution

The reported redundant OS server restarted Runtime after PCS 7 self-diagnostics reported an invalid TLGRT value for Machine.Software.WinCC.TagLoggingServer. The installation had been upgraded from PCS 7 V9.0 SP1 to V9.0 SP3 Update Collection 3 (UC3). The author later reported that Siemens Support identified PCS 7 V9.0 SP3 UC04 as the fix because it included a WinCC update. This is the resolution reported for that installation, not evidence that every TLGRT exception has the same cause.

Establish the installed component versions

Record the precise PCS 7 version, Update Collection, WinCC version/update on both redundant OS servers, and whether both servers have identical installed components. The PCS 7 Readme identifies version-specific software components and their update levels; do not treat the PCS 7 umbrella version as the WinCC component version. Compare the actual installation with the release notes and compatibility requirements for the applicable UC before planning remediation.

Controlled remediation and validation

Preserve the project, OS configuration, and recoverable server images/installation media; record redundancy state and the event sequence. 2. Confirm the TLGRT exception and restart behavior in Windows/WinCC diagnostics without repeatedly forcing a server restart. 3. Consult Siemens Support and the PCS 7 V9.0 SP3 UC04 installation/readme material for the exact WinCC update and supported upgrade path for the system. 4. Schedule the update with the redundant pair's approved maintenance procedure, ensuring one usable OS remains available and the system can be rolled back. 5. After the supported update, verify both nodes' component versions, redundancy synchronization, Tag Logging operation, event logs, and whether the exception and self-restart recur.

Avoid unsupported recovery shortcuts

The early forum reply suggested reinstalling Windows and installing PCS 7 V9.0 SP3 followed by UC03, but the thread later reports UC04 as the resolution. A clean reinstallation is disruptive and was not shown to be necessary; do not adopt it as a first-line procedure. Use it only under a system-specific recovery plan authorized by Siemens Support and the site.

Verification

A meaningful result is stable OS Runtime on both nodes through the relevant operating period, healthy redundancy state, no recurrence of the invalid TLGRT self-diagnostic value, and functioning Tag Logging. Confirm using system diagnostics and logs rather than relying only on a successful update installation or a single restart.

Limitations and Operational Precautions

The ticket does not include screenshots, full diagnostic logs, exact WinCC update numbers before and after, or an accessible public change note tying the defect to UC04. The UC04 fix is therefore presented as a Siemens Support resolution reported by the poster. Validate the fix against the installed component matrix and current Siemens support guidance before rollout. Updating a redundant OS pair can affect availability and requires backup, staged maintenance, and rollback planning.

Engineer FAQ

Which update resolved the reported case? The author reported that Siemens Support identified PCS 7 V9.0 SP3 UC04, including a WinCC update, as the resolution.

Does every TLGRT exception require UC04? The discussion establishes only one reported case. Similar text alone does not confirm the same root cause.

Should I reinstall the OS before trying the update? The thread's later resolution does not require that conclusion. Reinstallation was an early suggestion, not the confirmed reported fix.

What versions should be compared across redundant servers? Compare both the PCS 7 UC and the installed WinCC version/update and relevant OS components.

How do I confirm remediation? Check stable Runtime and redundancy, Tag Logging behavior, and recurrence of the diagnostic in logs after maintenance.

Technical References

PCS 7 Readme V9.0 including SP1 (online), illustrating the PCS 7 release's component-specific version/readme structure; it does not document this reported UC04 defect.
Siemens PCS 7 V9.0 SP3 UC04 support entry, referenced in Siemens product security guidance; the exact TLGRT change note was not available for independent review.