Connecting CEMAT C_DRV_1D Instance Data Blocks to WinCC Diagnostic Faceplates in SIMATIC PCS 7

In SIMATIC PCS 7 and CEMAT, engineers do not manually connect instance data block numbers (such as DB755) to WinCC faceplates (@PG_C_DRV_1D_DIAG). Instead, instantiate the C_DRV_1D block in a CFC chart within the plant hierarchy. The CFC compiler assigns the instance DB automatically and generates WinCC tags using the CFC block's symbolic tag name via the s7_m_c attribute. In Graphics Designer, place the standard CEMAT block icon linked to the tag name; clicking the icon at runtime automatically opens the faceplate with the server prefix and tag prefix applied dynamically.

PCS 7 and CEMAT Faceplate Architecture Principles

In traditional PLC-SCADA architectures (such as standalone STEP 7 and classic WinCC or WinCC Flexible), engineers frequently mapped individual tags by hardcoding DB numbers, offsets, and bit positions into screen elements. In SIMATIC PCS 7 and industry-specific suites like CEMAT (Minerals & Mining Library), this manual mapping is strictly obsolete and prohibited by the architecture.

When implementing a unidirectional motor drive block (C_DRV_1D), the controller program and operator station are bound by symbolic engineering. Trying to manually bind a raw DB number (like DB755) to a diagnostic faceplate such as @PG_C_DRV_1D_DIAG bypasses the entire PCS 7 OS compilation engine, resulting in unlinked variables, broken navigation, and non-functional buttons.

The Role of Instance DBs and the s7_m_c Attribute

Every function block placed in a Continuous Function Chart (CFC) requires an instance data block. The PCS 7 CFC compiler automatically creates and renumbers these instance DBs during compilation from an internal pool.

CEMAT blocks possess the system attribute s7_m_c = 'true' on all operator-controllable and diagnostic parameters (such as command outputs, feedback states, interlock inputs, and operating modes). When an engineer runs Compile OS:

The compiler reads the plant hierarchy path and block name (e.g., Plant1/RawMill/M01_Motor).
It automatically creates an internal WinCC Tag Structure named after the block type (C_DRV_1D).
It creates WinCC tags under the structured tag name Plant1/RawMill/M01_Motor.<Parameter>, referencing the exact DB number and byte offset assigned to that instance.

WinCC Tag Prefix Mechanics and Dynamic Faceplate Linking

CEMAT diagnostic faceplates (@PG_C_DRV_1D, @PG_C_DRV_1D_DIAG, @PG_C_DRV_1D_STANDARD) are completely generic templates. They contain no hardcoded DB addresses. Instead, all graphic objects inside the faceplate reference relative tag names, such as .STATUS, .SIM_ON, .EBVG, and .RUN_DIR.

When the operator clicks a block icon on a plant graphic:

The standard CEMAT C-script reads the block icon's Tag property (the full hierarchical tag path).
The script calls the faceplate window manager, which opens @PG_C_DRV_1D_DIAG.
The window manager injects the full tag name into the faceplate container's TagPrefix property (and server prefix if redundant).
WinCC dynamically resolves .STATUS into Plant1/RawMill/M01_Motor.STATUS, fetching live values from the controller without manual DB programming.

Step-by-Step CFC to Faceplate Engineering Workflow

To correctly implement and connect a CEMAT C_DRV_1D motor to its diagnostic faceplates:

Place C_DRV_1D in CFC: Open the target CFC chart within your plant hierarchy folder. Drag C_DRV_1D from the CEMAT library catalog into the chart. Assign it a meaningful block name (e.g., M101).
Connect Field Signals: Interconnect physical inputs and outputs (e.g., contactor run output COMMAND, contactor run feedback ERM, local stop ESPO, and operational interlock EBVG).
Enable OCM (Operator Control and Monitoring): Right-click the block, open Object Properties, and ensure the checkbox 'OCM possible' is checked. This tells the compiler to expose the block to WinCC.
Compile CFC and AS-OS Connection: Compile the CFC charts with 'Generate Module Drivers' enabled. Then right-click the OS and select Compile OS (Transfer AS/OS connection data).
Generate Block Icons in WinCC: In SIMATIC Manager, right-click the Plant Hierarchy and select Plant Hierarchy > Create/Update Block Icons. WinCC automatically generates the CEMAT motor icon in the corresponding process picture.
Runtime Verification: Activate WinCC Runtime. Click the motor icon to open the faceplate. Click the Diagnostics icon in the faceplate header to open @PG_C_DRV_1D_DIAG.

CEMAT C_DRV_1D Diagnostic Faceplate Structure

The following table describes the standard CEMAT faceplate views and their operational functions:

| Picture File Name | View Type | Key Display Parameters | Operator Functions Available |
|---|---|---|---|---|
| @PG_C_DRV_1D_STANDARD.PDL | Standard Operating View | Motor running state, local/auto/manual mode, current | Start, Stop, Mode Switch, Fault Reset |
| @PG_C_DRV_1D_DIAG.PDL | Diagnostic View | Feedback run error, interlock bypass, electrical faults | Detailed bit-level interlocking and hardware fault inspection |
| @PG_C_DRV_1D_INTERL.PDL | Interlock View | EBVG (operational), EEVG (essential), ESVO (safety) | Pin-by-pin permissive and trip status inspection |
| @PG_C_DRV_1D_PARAM.PDL | Parameter View | Feedback monitoring time (LNK_FBT), restart delay | Tuning drive timing parameters with authorization |
| @PG_C_DRV_1D_ALARM.PDL | Alarm History View | Time-stamped alarm list filtered strictly for this motor | Viewing chronological trip sequence and acknowledgments |

Verification

Verify the dynamic faceplate linking using the following steps:

Open the WinCC Tag Management editor on the OS. Search for the motor name and confirm that all CEMAT structure tags exist.
In Graphics Designer, open the process picture and select the generated block icon. Inspect the Tag property; verify it points to the full hierarchy path (e.g., Area01/SectionA/M101).
Launch WinCC Runtime. Click the motor block icon; the faceplate @PG_C_DRV_1D.pdl should open without script errors.
Click the 'Diagnostics' button. Confirm that the diagnostic window @PG_C_DRV_1D_DIAG opens and displays live feedback states, interlock states, and fault codes matching the online CFC chart.

Limitations and Operational Precautions

Consider these operational rules when engineering CEMAT faceplates:

Never Manually Edit @PG_... System Pictures: Standard @PG_ pictures are updated during CEMAT version migrations. Custom modifications should be implemented using user-specific faceplate variants or official CEMAT customization guidelines.
Hierarchy Path Restrictions: Avoid special characters (/, \, ', *, ?) and excessive hierarchy path lengths, as WinCC tag names have strict length limits (128 characters).
Server Prefix in Multi-Server Systems: In client-server environments, ensure the OS Server package is loaded on all clients so the window manager can resolve the server prefix for remote instance tags.

Engineer FAQ

What happens to instance DB numbers during CFC compilation?

CFC assigns instance DB numbers dynamically. If you recompile or reorganize the CFC program, the DB number can change, but symbolic references in WinCC remain fully valid.

How do I make a custom block parameter visible in the CEMAT faceplate?

In the SCL block source or CFC block definition, assign the system attribute S7_m_c := 'true' to the parameter and re-run OS Compile.

Why is the CEMAT diagnostic faceplate greyed out during runtime?

A greyed out faceplate indicates that the operator account lacks the required authorization level in WinCC User Administrator or the communication link to the AS is interrupted.