Resolving Missing Step OS Comments and Tooltips in PCS 7 SFC Visualization

Missing tooltip comments on SFC steps in WinCC SFC Visualization (SFV) under SIMATIC PCS 7 V8.2 occur when OS comments fail to transfer to the WinCC Text Library during AS-OS compilation or when a runtime language mismatch exists. In SFC engineering, step comments entered in the SFC Editor are language-dependent. If the AS engineering language differs from the active WinCC OS runtime language, tooltips remain blank. To resolve this issue, verify that the active WinCC language matches the STEP 7 project language, execute an AS-OS compilation with 'Entire OS' to rebuild the Text Library, and ensure the latest SFC Visualization V8.2 update is applied.

SFC Visualization Tooltip Architecture and Text Library Transfer

In SIMATIC PCS 7, SFC Visualization (SFV) allows operators to monitor and interact with Sequential Function Charts directly from WinCC OS client faceplates (@pg_@sfc_*.pdl). When an operator hovers the mouse pointer over an SFC step or transition icon, an automated tooltip should appear displaying the step name, configured run times, and the descriptive OS Comment.

The OS Comment is entered in the SFC Editor under Step Properties -> General -> OS Comment. During AS-OS engineering compilation, the compiler extracts these string literals and inserts them into the WinCC Text Library (TextDistributor / CCDataServer). At runtime, the SFC ActiveX control dynamically queries the Text Library using the internal text reference ID corresponding to the active runtime language.

Root Cause Analysis - Language Mismatch and Compilation Options

When tooltips fail to display in SFC Visualization, the root cause typically stems from one of three areas:
1. Language Inconsistency: In STEP 7, texts are assigned to specific languages (e.g., English (United States) vs English (United Kingdom)). If the project was configured in English (US) but WinCC OS Runtime is running under English (UK) or German, the Text Library has no entry for that language column, returning an empty string.
2. Outdated Text Library Cache: Delta AS-OS compilations may fail to register newly edited step comments. An entire OS compile is required to refresh text indices.
3. SFV Graphic Template Version: If SFC Visualization updates were installed on the Engineering Station without running the OS Project Editor on the OS Server, the runtime uses mismatched @sfc_*.pdl faceplate files that cannot communicate with the updated SFV ActiveX control.

Diagnostic Matrix for SFC Step Tooltips and OS Comments

The table below details diagnostic checkpoints, configuration parameters, and remedies for SFC tooltip display:

Checkpoint / ParameterLocationExpected StateFailure Impact & RemediationOS CommentSFC Step PropertiesText string enteredIf blank, no tooltip is generated; enter text in SFC Editor.AS LanguageSIMATIC Manager -> Options -> LanguageMatches WinCC RuntimeIf mismatched, export/import multilingual text via Text Management.WinCC Text LibraryWinCC Explorer -> Text LibraryText ID present with stringIf missing, perform AS-OS compilation with 'Entire OS'.OS Project EditorWinCC ExplorerExecuted after SFV updatesUpdates standard @pg_@sfc_*.pdl faceplates and ActiveX containers.Show TooltipsWinCC Computer Properties -> GraphicsEnabled (True)If disabled in Windows/WinCC, all graphic tooltips are suppressed.

Step-by-Step Remediation and Text Library Synchronization

Verify Language Consistency: In SIMATIC Manager, select Options -> Manage Multilingual Texts -> Change Language. Verify the default project language (e.g., English (United States)). In WinCC Explorer, verify that the runtime default language matches the exact same national locale.
Export and Verify Step Texts: Select Options -> Manage Multilingual Texts -> Export.... Export the project texts to a spreadsheet; verify that SFC step comments are populated in the active language column.
Rebuild WinCC Text Library via Entire OS Compile:
- In SIMATIC Manager, right-click the OS Server object and select Compile.
- Choose Entire OS and check With memory reset.
- Complete compilation to force re-indexing of all SFC step text IDs into the WinCC SQL database.
Update SFC Faceplates with OS Project Editor:
- Open WinCC Explorer on the OS Server.
- Open OS Project Editor, navigate to the Basic Data tab, ensure SFC screen updates are checked, and click OK.
Apply Latest SFC Visualization Update: If running baseline PCS 7 V8.2, install SFC Visualization V8.2 Upd1 (or higher) on both ES and OS clients to ensure full Windows 7/Server 2012 R2 compatibility.

Verification

Verify tooltip restoration through the following steps:
1. Open WinCC OS Runtime on an Operator Station.
2. Open an SFC chart faceplate and navigate to an active or inactive step.
3. Hover the mouse cursor over the step symbol: confirm that a tooltip pops up displaying the Step Name, Min/Max Run Time, and the exact OS Comment text configured in the AS.
4. Toggle the WinCC runtime language (e.g., between English and German, if configured): confirm that localized tooltips switch cleanly without requiring an OS restart.

Limitations and Operational Precautions

Avoid entering extremely long OS comments in SFC steps. While the Text Library supports long strings, the WinCC tooltip rendering window has display boundaries; keep step comments concise (under 80 characters) to ensure full legibility in high-resolution control room displays. Furthermore, never edit @sfc_*.pdl template files directly in Graphics Designer, as any execution of the OS Project Editor will overwrite manual edits.