Displaying Motor Restart Lockout Countdown Timers on WinCC Faceplates for CEMAT C_DRV_1D

To display a motor restart lockout countdown timer on a WinCC V7.4 faceplate for CEMAT block C_DRV_1D, you cannot use standard APL UserAna1/UserAna2 pins because CEMAT utilizes an independent block architecture. Instead, implement one of two supported engineering methods: (1) In CFC, interconnect the elapsed or remaining time output of the start-interlock timer (e.g., TimerP or C_TIM_P) into a companion CEMAT analog measurement block (C_MEASUR) and link it as an associated value to the drive; or (2) In WinCC Graphics Designer, customize the C_DRV_1D standard faceplate (@PG_C_DRV_1D.pdl) by inserting an I/O Field dynamically bound to the timer's remaining time tag, formatted as an integer seconds or mm:ss countdown display.

Executive Summary

In cement, mining, and heavy material handling plants operating under the SIMATIC PCS 7 CEMAT industry standard, large medium-voltage (MV) crusher and mill motors require thermal restart lockout protection. To prevent motor stator and rotor overheating caused by frequent starts, engineering logic incorporates a cooldown timer (typically 15 to 30 minutes) into the start interlock (EBM/ESB) of the single-direction drive block C_DRV_1D. While the interlocking timer operates reliably in the AS controller, operators are left blind if the WinCC faceplate merely indicates 'Start Interlock Active' without displaying the remaining countdown time. Because CEMAT blocks lack standard APL auxiliary display inputs (UserAna1), automation engineers must implement specialized CEMAT measurement links or customize the WinCC faceplate.

Architecture and Fundamental Mechanics

The display architecture of CEMAT faceplates differs fundamentally from standard APL blocks:

APL vs. CEMAT Faceplate Philosophy:
- In standard PCS 7 APL blocks (e.g., MotL), Siemens provides auxiliary inputs (UserAna1, UserAna2). Any analog value wired to these pins automatically renders in the faceplate standard view with engineering units without touching WinCC graphics.
- In CEMAT (e.g., C_DRV_1D), the block is designed around industry-specific mineral processing workflows. It does not provide UserAna1 pins. Faceplate data exchange is governed by dedicated structure tags, status words, and associated measurement blocks.
The CEMAT Associated Measurement Concept (C_MEASUR):
- CEMAT coordinates multi-variable drive monitoring by associating specialized satellite blocks with the parent drive.
- A C_MEASUR block represents analog values (bearing temperatures, motor current, vibration, or countdown timers). In the CFC chart, the C_MEASUR block is linked to C_DRV_1D via technological hierarchy assignment or parameter linking.
- The standard CEMAT faceplate includes an 'Associated Values' button that opens the linked analog measurement faceplate, displaying the countdown timer with trend and limit monitoring.
Direct WinCC Faceplate Customization (@PG_C_DRV_1D.pdl):
- If plant operators require the countdown timer to appear directly on the main faceplate canvas, the faceplate graphic file (@PG_C_DRV_1D.pdl or its standard view @PG_C_DRV_1D_STANDARD.pdl) can be edited in WinCC Graphics Designer.
- By adding an I/O Field configured with a tag prefix link, the faceplate dynamically reads the remaining time tag directly from the timer's instance DB.

Step-by-Step Implementation Procedure

Implement the restart lockout countdown display using one of the following methods:

Method 1: Faceplate Customization in WinCC Graphics Designer (Direct Countdown View)

Expose Timer Remaining Time in CFC:
- In the motor CFC chart, locate the timer block driving the start interlock (e.g., TimerP or C_TIM_P).
- Note the parameter outputting remaining time: for TimerP, use P_Time (or remaining time calculation Ti - Time).
- Ensure the parameter has { S7_m_c := 'true' } enabled so it is transferred to WinCC Tag Management during OS compilation.
Modify the CEMAT Faceplate in Graphics Designer:
- In WinCC Explorer, open Graphics Designer.
- Save a project backup copy of @PG_C_DRV_1D_STANDARD.pdl before modifying.
- Open @PG_C_DRV_1D_STANDARD.pdl.
- Insert an I/O Field (from Smart Objects) into an unused section of the faceplate.
- In Properties -> Low/High Limits, set format to Decimal or Time (e.g., 999 s or mm:ss).
- In Properties -> Output Value, configure dynamic tag binding:
- Use dynamic tag prefix substitution: TagPrefix + '.Timer_P_Time' (or the symbolic tag name of the timer output).
- In Properties -> Display / Visibility, bind visibility to a boolean flag: visible only when the timer is active (Timer.Running == 1).
- Add a static text label: Restart Lockout:.
- Save the PDL file in the local project GraCS folder.

Method 2: The CEMAT Standard Associated Block Method (No Graphic Edits)

In the motor CFC chart, insert a C_MEASUR block.
Connect the timer remaining time output to C_MEASUR.MV.
Set C_MEASUR.UNIT to 's' or 'min'.
In the C_DRV_1D block properties, link the C_MEASUR block under the associated measurement list.
Compile the OS. The CEMAT faceplate automatically creates a navigation jump button to the timer's measurement display.

Verification

Verify countdown visualization and interlock coordination:

Motor Stop Trigger: In WinCC Runtime, stop the motor. Confirm that the restart lockout timer starts immediately in the AS.
Faceplate Countdown Inspection: Open the C_DRV_1D faceplate. Confirm that the 'Restart Lockout' field illuminates, displaying the remaining seconds or minutes decrementing in real time.
Start Invalidation: Attempt to command a motor start while the countdown is active. Confirm that C_DRV_1D rejects the command due to the active start interlock (EBM).
Timer Expiration: Allow the timer to reach zero. Confirm that the countdown field disappears (or indicates 0), the start interlock clears, and the motor command buttons return to active/ready status.

Limitations and Operational Precautions

If customizing @PG_C_DRV_1D_STANDARD.pdl directly, ensure you uncheck this picture in the OS Project Editor Basic Data tab; otherwise, future OSPE runs or CEMAT updates will overwrite your modifications. Furthermore, ensure timer data types match WinCC I/O Field formatting: S5TIME values must be converted to standard integers or REAL seconds before display in WinCC.

Engineer FAQ

Why doesn't C_DRV_1D have UserAna1 like standard APL blocks?

CEMAT was developed as an independent industry standard for minerals and cement before the APL style guide was established, utilizing associated measurement blocks (C_MEASUR) rather than internal auxiliary analog inputs.

How can I format S5TIME values into readable seconds in WinCC?

Convert the S5TIME or TIME value in the AS to a REAL or DINT representing total seconds (divide milliseconds by 1000.0) before transmitting to WinCC.

Will modifying @PG_C_DRV_1D affect all motors in the plant?

Yes. Modifying the standard faceplate template in the GraCS directory applies the new display field to all C_DRV_1D instances across the entire WinCC OS project.

Can the countdown timer display be hidden when the motor is running?

Yes. By binding the I/O Field's Visible property to the timer's active status bit, the field remains completely hidden during normal motor operation.