Troubleshoot a Frozen PCS 7 Runtime Clock with CP 1623
When a PCS 7 runtime clock stops updating, inspect its time source and synchronization path before changing the display. A CP 1623 configured to receive time without an identified master leaves the time architecture incomplete. Siemens documents a workgroup configuration using OS servers as cooperative time masters, but the reported PCS 7 V9.0 SP3 installation must be checked against its applicable documentation. A crossed-out clock alone does not establish the cause.
Table of Contents
- Symptoms and Applicability
- Documented Workgroup Configuration
- Verification
- Limitations and Operational Precautions
- Engineer FAQ
- Technical References
- Related Articles
- Related Tags
Symptoms and Applicability
The reported configuration combines PCS 7 V9.0 SP3, WinCC V7.4 and a CP 1623. The runtime overview shows an unchanged time with a line through it. The CP is configured as a time receiver, but no supplying master has been identified.
The reported WinCC version lacks its service-pack and update detail. Record those components and whether the station is an OS server, client or single station. Also establish whether the computers belong to a workgroup or domain. Those distinctions determine the applicable synchronization configuration.
Documented Workgroup Configuration
The closest documented procedure is Time Synchronization V9.0 SP2, A5E39221891-AC, section 6.4.3.2, printed pages 83-84. It applies to a workgroup without a central time master, with supported adapters enabled for time operation and automation systems configured as slaves. It is not a domain procedure.
- On the engineering station, open the OS server project in WinCC Explorer.
- Open the
Time synchronizationeditor. - Enable
Synchronization via System Bus (Master, Slave)andDisplay symbolic name of the access points. - Select the plant-bus adapter in
Access point 1and chooseMaster. - If a supported redundant adapter is present, assign
Access point 2and itsMasteroption. - Confirm with
OK.
The documented result is cooperative time-master operation. Apply the release-specific project deployment procedure separately. The AS can be synchronized in this configuration only while an OS server is active. See the manufacturer procedure.
Verification
For CP 16x3/16x8 diagnostics, section 7.2 documents opening Siemens Automation > SIMATIC > SIMATIC NET > Communication settings, then Modules > <CP...> > Time of day. Check enabled time-of-day adjustment and a synchronous time-reception indication.
As a practical acceptance check, observe that the runtime clock advances and compare it with the intended reference. Record the CP indication, runtime observation and source identity together. An accepted editor setting alone does not establish correct time delivery.
Limitations and Operational Precautions
The reference is V9.0 SP2, whereas the installation is reported as V9.0 SP3. Its applicability and the precise cause of the crossed-out display remain unconfirmed. The reply's interpretations of X and ?? are not independently established here and are not used to prescribe a repair.
Internal time consistency does not by itself prove agreement with real local time. A valid source architecture and display/time-zone settings must both meet the plant's requirements.
Preserve project and network settings before changes. Coordinate time-source changes with the plant's event-history requirements and validate in an approved maintenance environment. No repair or laboratory test is claimed.
Engineer FAQ
Should the CP simply be changed to master? Establish the whole architecture first; the documented cooperative-master selection is made in the OS server project.
Does the workgroup procedure apply to a domain? No. Select the domain-specific procedure for that architecture.
Does a synchronous CP prove the overview is correct? It is supporting evidence; verify the displayed time independently.