Resolving WinCC Text Library Language Conflicts and Persistent 'Diagnostics' Text Overwrites in PCS 7

In SIMATIC PCS 7, when an imported project uses a different regional language (such as English Australian instead of English US), compiling the OS can corrupt the WinCC Text Library, causing APL faceplates to display incorrect labels or continuously overwrite Line 80 with the word 'Diagnostics'. This defect occurs because the OS compiler assigns Text IDs based on the master language defined in STEP 7; language mismatches cause Text ID pointer collisions. To permanently resolve this, change the project default language in SIMATIC Manager to match the existing multiproject ('English (United States)'), execute an OS compile twice in succession (allowing the compiler to re-index displaced text IDs into Line 81 and beyond), and run the OS Project Editor with 'Complete configuration' to restore default system message catalogs.

Executive Summary

During multi-user engineering or modular project integration, inserting a project developed on an ES with different Windows regional settings (for example, English Australian en-AU vs. English United States en-US) introduces subtle language conflicts into the SIMATIC PCS 7 multiproject. When the Operator Station (OS) is compiled, the text translation tables between STEP 7 and WinCC become misaligned. A frequent manifestation is Line 80 in the WinCC Text Library being persistently overwritten with 'Diagnostics', which distorts APL faceplate command buttons and interlock displays. Even if an engineer manually deletes the text, the subsequent OS compile restores the incorrect entry. Realigning project languages, leveraging sequential double OS compilations, and regenerating the OS Project Editor restores Text Library integrity.

Architecture and Fundamental Mechanics

The text management subsystem in SIMATIC PCS 7 coordinates multilingual strings across the AS engineering environment and the WinCC runtime database:

Text Catalogs in STEP 7 and WinCC:
* In STEP 7, block comments, I/O pin names, unit strings, and alarm templates are stored with language tags (e.g., Language for display devices in SIMATIC Manager).
* WinCC maintains a centralized SQL database table called the Text Library (TxtLib), where every multilingual text is assigned a unique, integer-based Text ID.
* Graphic objects (such as APL faceplate popups @PG_APL_OA.pdl) reference Text IDs rather than static string literals to support dynamic runtime language switching.
The Impact of Regional Language Mismatches:
* When a project configured in English (Australia) is merged into a multiproject whose default language is English (United States), the OS compiler encounters two distinct language IDs.
* The compiler attempts to merge text records. If the source project's text catalog is shifted, the compiler misinterprets the base index of system diagnostic strings.
* Line 80 in the Text Library is reserved in standard WinCC projects for specific system or interlock display headings. Due to index misalignment, the compiler maps the string 'Diagnostics' directly to Text ID 80, overriding the command button text required by APL faceplates.
The 'Compile Twice' Phenomenon:
* During the first OS compilation following language correction, the compiler detects that Text ID 80 is occupied by a conflicting object. It marks the conflict and creates a new index (Line 81 or higher) for the displaced text.
* However, internal cross-references in the @PG_*.pdl screens are not updated until a second compilation pass parses the newly created text ID mapping and binds the graphic objects to the relocated index.

Step-by-Step Implementation Procedure

Follow these procedures to eliminate Text Library corruption and restore correct faceplate texts:

Standardize Project Languages in SIMATIC Manager:
* In SIMATIC Manager, select the top-level Multiproject folder.
* Select Options > Language for display devices....
* In the dialog, verify the installed and active languages.
* Select English (United States) as the default language.
* If regional variants like English (Australia) or English (United Kingdom) appear, select them and click Delete (or remove them from the active list).
Propagate Language Settings to All S7 Programs:
* Open each individual project within the multiproject.
* Navigate to Options > Manage Multilingual Texts > Change Language....
* Set the primary language to English (United States) and confirm.
Execute the First OS Compilation:
* Right-click the OS object in SIMATIC Manager and select PLC > Compile and Download Objects (or right-click OS > Compile).
* Under Scope, select Entire OS (or Changes only if preferred, though Entire OS is recommended for language rebuilds).
* Select 'Tags and messages' and 'SFC visualization'.
* Complete the compilation.
Execute the Second OS Compilation:
* Immediately initiate a second OS compile with the identical scope.
* The second compilation shifts the 'Diagnostics' string pointer to Line 81 and re-links the APL faceplate interlock and command references cleanly.
Run the OS Project Editor:
* Open the OS project in WinCC Explorer.
* Double-click OS Project Editor.
* On the Layout tab, verify the monitor configuration.
* On the Basic Data tab, ensure that standard APL screens and text configurations are checked.
* Click OK to regenerate standard system scripts and text mappings.
Verify the Text Library in WinCC Explorer:
* Open Text Library in WinCC Explorer.
* Inspect Line 80. Verify that it now reflects the standard system text rather than being forcibly overwritten with 'Diagnostics'.

Verification

After completing the second OS compile and running the OS Project Editor, activate WinCC Runtime. Open several APL faceplates (such as MotSpdCL, VlvAnL, and Interlock). Verify that command popups, interlock bypass buttons, and diagnostic tabs display their correct English (United States) labels without missing text or '???'. In the Text Library editor, verify that Line 80 and Line 81 contain properly separated system strings.

Limitations and Operational Precautions

Do not delete or edit Text Library entries with low IDs (IDs below 10,000) manually in WinCC Explorer, as these IDs are reserved for internal WinCC and APL system functions. Always perform language management through SIMATIC Manager's Language for display devices tool rather than directly modifying SQL tables.

Engineer FAQ

Why did deleting the word in Line 80 not fix the problem permanently?

The OS compiler regenerates text strings based on the AS project database upon every compile. If the underlying language conflict is not resolved, the compiler will recreate the incorrect entry every time.

Why is compiling the OS twice necessary?

The first compile identifies the index collision and allocates a new text ID (e.g., Line 81); the second compile updates the cross-reference pointers in the graphic pictures to point to the new ID.

Can different regional dialects of English cause PCS 7 errors?

Yes. STEP 7 treats English (US), English (UK), and English (Australia) as completely different language locales with separate text columns in the database.