Delete Obsolete Pending Messages in PCS 7 OS Runtime Without Restarting
Siemens provides a DeleteAlarm example display for removing obsolete, non-acknowledgeable messages from PCS 7 OS Runtime without restarting the OS. Identify each genuinely obsolete message before using it. For the reported V9.0 SP1 configuration, the documented approach addresses stale entries after block deletion, but the behavior of deleting an alarm that is still physically active remains unverified and must not be treated as safe alarm clearing.
Table of Contents
- Confirm That the Message Is Obsolete
- Prepare the Documented DeleteAlarm Display
- Delete Only the Verified Message
- Verification
- Limitations and Operational Precautions
- Engineer FAQ
- Technical References
- Related Articles
- Related Tags
Confirm That the Message Is Obsolete
Use deletion only after identifying a message that no longer represents a real pending condition. In the reported PCS 7 V9.0 SP1 configuration, blocks had been deleted from the AS while entries remained in the pending list. The plant used redundant OS servers and several clients.
A crossed-out appearance alone is insufficient justification. Match the message to the removed engineering object and inspect the current process condition. Preserve its identity and event history for review before removal.
Prepare the Documented DeleteAlarm Display
Siemens support entry 109751476 describes removal without restarting the OS. The opened January 2025 revision explicitly includes PCS 7 V9.0; it is identified here as that revision, not the historical edition cited in the discussion.
- Obtain the matching example archive 109751476_DeletePendingMessage_PROJ_PCS7V90.zip from the support entry.
- In SIMATIC Manager, use File > Dearchive, select the archive and open it in a chosen folder.
- Switch to Plant View and open the target project in parallel.
- Copy DeleteAlarm from DelSelMes_Proj into the target technological hierarchy at a level configured as an OS area.
- Compile the OS after completing the target-project work.
Siemens procedure, Preparation. Apply the resulting OS change through the site's approved deployment process. The cited document does not supply a complete redundant-server deployment plan.
Delete Only the Verified Message
- In the target OS Runtime, open DeleteAlarm.
- Select the verified obsolete message in WinCC AlarmControl.
- Click Delete selected message.
- In Comment on message, record the reason and confirm with OK.
- Repeat only for independently verified obsolete entries.
- When finished, remove DeleteAlarm from the technological hierarchy and recompile the OS.
The documented operation removes the message from the message system and records its removal in the archive. Siemens procedure, Deleting the message.
Verification
Confirm the selected obsolete entry is removed and the archive contains the removal record. Check that the chosen message identity matches the reviewed obsolete object.
Keep independent observation of the current plant state. Deleting a message does not clear its physical cause. The discussion reports that deleting a genuinely pending message leaves it absent until a new signal transition; that recurrence behavior was not independently verified for the exact installation. Do not use deletion to test it on an active production alarm.
Limitations and Operational Precautions
The example procedure is documented for the stated product family, but the exact example-package compatibility and server deployment need checking against the installed V9.0 SP1 system. The guide was opened; the example archive was not downloaded or executed.
The central documented method is available, while the question about deleting an actually pending alarm remains unresolved. This article therefore requires technical review before publication. Preserve backups, removal records and the required alarm visibility. No runtime deletion or laboratory testing was performed.
Engineer FAQ
Can obsolete messages be removed without an OS restart? Siemens documents the example-display method above.
Does deleting an alarm fix the process? No; inspect and resolve the actual process condition separately.
Should active alarms be deleted as a diagnostic experiment? No; the recurrence and visibility consequences are not established here.