Activating the Quick Stop Button on CEMAT C_GROUP Faceplates in SIMATIC PCS 7: Configuring StyleTag and Block Attributes

In SIMATIC PCS 7 CEMAT, the Quick Stop button in the C_GROUP operator faceplate is controlled by the StyleTag property of the group's block icon in WinCC Graphics Designer. By default, the C_GROUP block icon has StyleTag set to 1, which suppresses the Quick Stop button and displays standard Start and Stop commands. Setting StyleTag to 2 in the block icon properties enables the Quick Stop button in the runtime faceplate (@PG_C_GROUP.PDL), allowing operators to bypass group run-down sequencing and issue immediate de-energization commands directly to all linked drives.

CEMAT C_GROUP Operational Commands and Quick Stop Functionality

In the SIMATIC PCS 7 CEMAT library, technological group block C_GROUP coordinates the startup and shutdown sequence of related drives, dampers, and auxiliary equipment (such as a clinker conveying line or raw meal grinding circuit). Under normal operational conditions, stopping a group initiates a cascaded run-down sequence where upstream material feed drives stop first while downstream conveyor belts continue running for a preset purge time to empty material.

However, operational events may necessitate a Quick Stop—an immediate, non-delayed cessation of all group drives without waiting for purge sequences, while maintaining group interlocking integrity.

Role of StyleTag in CEMAT Block Icons and Faceplates

In CEMAT, runtime faceplate features are frequently parameterized through the block icon attributes rather than PLC block inputs alone. The group faceplate @PG_C_GROUP.PDL is a universal template. When an operator clicks a C_GROUP block icon, WinCC passes the icon's custom attributes into the faceplate script engine:

The attribute StyleTag dictates the visual layout and available command buttons.
When StyleTag == 1 (default), the faceplate renders standard buttons: Start, Stop, and mode selectors.
When StyleTag == 2, the faceplate script exposes the Quick Stop button, enabling operators to command rapid de-energization.
Higher StyleTag values or custom variants may enable maintenance-specific controls according to cement plant specifications.

Differences Between Standard Stop and Quick Stop in Minerals Processing

Understanding the operational distinction is critical for process safety:

Standard Stop (GTA): Initiates controlled shutdown. Upstream units trip; downstream units execute run-down timers (TUG) to clear belts, preventing conveyor overload and material spillage.
Quick Stop (GQS / QSTOP): Immediately trips all subordinate drives simultaneously. This is used when a chute blockage or equipment abnormality is detected where allowing material to continue feeding downstream would cause catastrophic mechanical binding, but an Emergency Stop (hardwired safety circuit) is not legally required.

Configuring StyleTag on C_GROUP Block Icons in WinCC Graphics Designer

To configure StyleTag:

Open the WinCC project on the Engineering Station.
Open the process picture containing the C_GROUP block icon in Graphics Designer.
Select the C_GROUP block icon (e.g. @C_GROUP/1 or @C_GROUP/2).
Open the Object Properties window.
Navigate to the User Interface or General property group.
Locate the property StyleTag (Data Type: Integer or Long).
Change the static value from 1 to 2.
Save the picture and compile/download OS changes to the target servers and clients.

CEMAT C_GROUP Icon StyleTag Configuration Matrix

The following table outlines the behavioral states associated with StyleTag settings on CEMAT group modules:

StyleTag SettingVisible Faceplate ControlsOperational BehaviorShutdown Sequence TypePrimary Plant ApplicationStyleTag = 1 (Default)Start, Stop, Interlock InfoStandard cascaded group sequencingTime-delayed purge run-downGeneral bulk handling linesStyleTag = 2Start, Stop, Quick Stop, Interlock InfoInstant group shutdown available on buttonImmediate simultaneous drive tripCrushers, ball mills, jammed chutesStyleTag = 3Start, Stop, Quick Stop, Local ReleaseLocal and remote maintenance controls enabledImmediate trip + local bypassMaintenance-intensive transport sectionsStyleTag = 0 / UndefinedMinimal layout (Status only)Command buttons suppressedManual drive-by-drive interventionRead-only overview displays

Step-by-Step Procedure to Enable and Test the Quick Stop Command

Follow these engineering steps to deploy the Quick Stop button across plant groups:

Template Block Icon Adjustment (Optional): If all group icons should display Quick Stop by default, open template picture @PCS7Typicals_Cemat.pdl. Select @C_GROUP/1, set StyleTag = 2, and save. Future automated OS compilations with Create/Update Block Icons will inherit this setting.
Instance Adjustment: Open the plant graphic PDL in Graphics Designer. Select the specific group icon, change StyleTag to 2 in Object Properties.
Verify AS Block Logic: In CFC, ensure the C_GROUP block has input GQSP (Quick Stop Pulse) or command structure linked appropriately if external signals also trigger quick stops.
Save and Download: Save the graphic picture. Download OS changes to the OS Server and OS Clients.
Runtime Activation: In WinCC Runtime, click the group block icon to open @PG_C_GROUP.PDL. Confirm that the Quick Stop button is visible.
Operator Permission Check: Verify that the operator account has authorization level 5 (Process Controlling) or 6 (Higher Process Controlling) to depress the Quick Stop button.

Verification

Perform these verification tests to confirm functionality:

Visual Button Inspection: Open the group faceplate in WinCC Runtime. Verify the red or designated Quick Stop command button appears adjacent to Stop.
Simulation / Cold Run Test: Start the group in simulation or test mode so all drives enter running status. Click Quick Stop.
Run-down Bypass Check: Confirm that all linked drives de-energize immediately without waiting for individual drive run-down timers (TUG).
Alarm Generation: Verify that the WinCC Alarm Logging list records a group quick stop operator command with operator user stamp.

Limitations and Operational Precautions

Observe the following safeguards:

Not a Safety Function: The CEMAT Quick Stop command is a software-based operational stop implemented over WinCC and industrial Ethernet. It does not replace hardwired or fail-safe Emergency Stop systems (SIL / PL ratings under IEC 62061 / ISO 13849).
Mechanical Stress: Repeated use of Quick Stop on fully loaded conveyor belts or ball mills can cause material piling, chute clogging, or mechanical shock. Train plant operators to reserve Quick Stop for operational emergencies.
Commercial Accuracy Disclaimer: Software order numbers (MLFBs), package structures, and hardware capacity prerequisites vary across PCS 7 versions and hardware platforms. System integrators must confirm exact software entitlements and licensing requirements against the official Siemens Catalog CA 01 and obtain an authorized Siemens distributor quotation prior to purchasing.

Engineer FAQ

Can I trigger Quick Stop automatically from an interlock rather than the operator faceplate?

Yes. The C_GROUP block in CFC provides technological input pins such as GQSP (Quick Stop Pulse) which can be connected to interlock blocks or protective monitoring logic.

Why does the Quick Stop button appear greyed out after setting StyleTag to 2?

A disabled button indicates that the current logged-in WinCC user lacks authorization level 5 or 6 (Process Controlling), or the group is already in a stopped or faulted state where stopping is not an allowable operation.

Does Quick Stop bypass the drive interlocks?

No, Quick Stop initiates an immediate stop command across group members; it does not bypass safety interlocks or protection interlocks on individual drives.