Troubleshooting CEMAT C_GROUP Faceplate Opening Failures and Missing Diagnostic Windows in WinCC

In SIMATIC PCS 7 running the CEMAT Minerals and Mining library, the failure of the C_GROUP faceplate to open or the absence of its diagnostic sub-windows in WinCC is primarily caused by missing CEMAT global C-script functions, omitted CEMAT OS updates, or insufficient operator authorization levels. Unlike standard APL faceplates, CEMAT C_GROUP faceplates rely on dedicated C-script files (c_group.c, cemat_user_auth.c) and specialized system PDL screens (@PG_C_GROUP.PDL, @PG_C_GROUP_DIAG.PDL). To resolve this, run the 'CEMAT Update OS' utility to copy current system PDLs and C-scripts into the WinCC project directory, regenerate script headers in the Global Script C editor, and assign WinCC User Administrator authorization level 5 or 6.

Architecture of the CEMAT C_GROUP Technological Block and WinCC Interface

The SIMATIC PCS 7 CEMAT library (e.g. CEMAT V6.1, V7.1, V8.0, or V9.0, 6ES7658-2BC58-0YA5) is the global Siemens standard for cement plants, mining facilities, and bulk solids processing. Central to the CEMAT operational philosophy is the Group Control Block (C_GROUP, FB1010), which orchestrates automated startup sequences, interlocking drives, dampers, and route selections for complex conveyor belts, kilns, and ball mills.

In the WinCC Human-Machine Interface, the C_GROUP block icon links to a multi-tiered faceplate architecture:
- Standard Faceplate (@PG_C_GROUP.PDL): Provides start, stop, immediate stop commands, and operating mode selection (Automatic, Manual, Local).
- Diagnostic Window (@PG_C_GROUP_DIAG.PDL): Displays critical interlocks, startup preconditions, drive status, and fault signals.
- Subordinate Module Displays (@PL_C_GROUP.PDL): Links directly to child drives (C_DRV_1D, C_DRV_2D) and dampers (C_DAMPER).

These faceplates do not rely solely on WinCC Tag Management; they execute compiled ANSI-C scripts located in the WinCC project directory (<Project>\Library\ and <Project>\GraCS\).

Root Causes of C_GROUP Faceplate Launch Failures in WinCC Runtime

When an operator clicks a C_GROUP block icon and the faceplate fails to open or opens as an empty white rectangle, investigation typically reveals one of four configuration errors:

Missing or Outdated System PDLs: Following a PCS 7 or CEMAT software update, the project's GraCS directory was not refreshed. WinCC cannot locate @PG_C_GROUP.PDL or its diagnostic screen @PG_C_GROUP_DIAG.PDL.
Uncompiled or Missing Global C-Scripts: CEMAT faceplates execute C-functions such as c_group.c, cemat_user_auth.c, and C_GROUP_Open.c. If header files (cemat.h) are out of date or if headers were not regenerated in WinCC Global Script, the C runtime engine aborts script execution silently.
Insufficient WinCC User Authorization: CEMAT enforces strict hierarchical security. Access to group control faceplates and diagnostic views requires specific authorization levels in WinCC User Administrator (typically Level 5 - Process Control and Level 6 - Higher Process Control). If the logged-in operator lacks these rights, the script denies faceplate generation.
Mismatched AS-OS Structure Tags: If block compilation from CFC to OS did not execute with memory reset, tag prefix pointers between WinCC and the S7-400 CPU fail to bind.

Comparison of CEMAT Faceplate Dependencies Across Library Versions

The following table compares CEMAT faceplate implementation characteristics across versions:

CEMAT VersionFaceplate EngineScript TechnologyDiagnostic Screen NameOS Update RequirementCEMAT V6.0 / V6.1Classic WinCC FaceplateGlobal C-Scripts (*.c)@PG_C_GROUP_DIAG.PDLManual batch script copy (CEMAT_Update_OS.bat)CEMAT V7.0 / V7.1Enhanced Picture WindowsGlobal C + WinCC ODK@PG_C_GROUP_DIAG.PDLIntegrated CEMAT OS Update ToolCEMAT V8.0 / V8.1Modernized Window ManagerC-Scripts + VBScript@PG_C_GROUP_DIAG.PDLOS Project Editor + CEMAT OS UpdateCEMAT V9.0 / V9.1APL-Style Window FrameworkHybrid C / VBS / APL Core@PG_C_GROUP_DIAG.PDLCEMAT Migration Tool + OS Project Editor

Step-by-Step Procedure to Restore CEMAT C_GROUP Faceplates and Diagnostics

Follow this engineering procedure to restore missing C_GROUP faceplates and diagnostic views:

Execute the CEMAT OS Update Tool:
- Close WinCC Explorer on the Engineering Station.
- Navigate to the CEMAT installation directory (typically C:\CEMAT_CS\tools\ or C:\Program Files (x86)\Siemens\CEMAT\Tools\).
- Run CEMAT_Update_OS.exe (or CEMAT_Update_OS.bat). Select your active WinCC project path.
- Confirm the execution. This copies all required @PG_C_GROUP*.PDL, @PL_C_GROUP*.PDL, and global C-scripts into the project's GraCS and Library directories.
Regenerate Script Headers in Global Script C:
- Open the WinCC project in WinCC Explorer.
- Open Global Script -> C-Editor.
- Select Options -> Regenerate Header (or press Ctrl+Shift+H). Wait until the compiler reports successful regeneration of all header files.
- Compile project functions and verify that 0 errors are reported.
Verify WinCC User Administrator Authorization Levels:
- In WinCC Explorer, open User Administrator.
- Ensure that the operator group is assigned Authorization Level 5 (Group Operation) and Authorization Level 6 (Interlock Override / Diagnostic View).
Recompile AS-OS and Restart Runtime:
- In SIMATIC Manager, perform an AS-OS compilation with 'With memory reset' to synchronize all CEMAT structure tags.
- Download the updated OS project to the target OS Server and Client stations.
- Start WinCC Runtime and verify faceplate launch.

Verification

Verify proper faceplate operation in WinCC Runtime:
1. Click the C_GROUP block icon on an overview mimic screen.
2. Confirm that the main faceplate @PG_C_GROUP.PDL opens centered above or adjacent to the icon.
3. Click the Diagnostic button (wrench or magnifying glass icon). Verify that the diagnostic sub-window opens cleanly, displaying all operational interlocks, running feedback states, and startup preconditions.
4. In the WinCC diagnostic console (APDIAG.exe), verify that no script errors or missing function warnings are logged during faceplate navigation.

Limitations and Operational Precautions

Do Not Overwrite Custom CEMAT Scripts Without Backup: Many plants customize CEMAT C-scripts (e.g. customized horn handling or group interlocking). Running CEMAT_Update_OS.exe overwrites files in <Project>\Library. Always take a complete project backup prior to running update tools.
CEMAT and PCS 7 Version Pairing: CEMAT versions must strictly match the underlying PCS 7 release (e.g. CEMAT V8.2 on PCS 7 V8.2; CEMAT V9.0 on PCS 7 V9.0). Never install mismatched CEMAT hotfixes.
OS Client Synchronization: After updating C-scripts on the ES/Server, OS Client projects must be refreshed; otherwise, clients execute local cached script files.

Engineer FAQ

Where is the Diagnostic button on the CEMAT C_GROUP faceplate?

The Diagnostic button is located on the header navigation toolbar of @PG_C_GROUP.PDL. If the button is greyed out or missing, the currently logged-in user lacks User Authorization Level 6 (Interlock/Diagnostics), or the diagnostic picture @PG_C_GROUP_DIAG.PDL is missing from GraCS.

Why does clicking C_GROUP do nothing in WinCC Runtime?

If clicking the block icon produces no action and no error dialog, the mouse-click action script is aborting because of a missing global C-script or missing header file. Check the WinCC_Sys_*.log file in WinCC\Diagnose for script error codes.

Do I need to compile the OS with memory reset for CEMAT changes?

Yes. When adding new CEMAT blocks or updating CEMAT libraries, compiling AS-OS with 'With memory reset' ensures that all UDT structures, internal status words, and tag prefixes are completely rebuilt in WinCC Tag Management.