How to Customize APL VlvMotL Block Icons and Faceplates for Auxiliary Motor and Actuator Diagnostics

In SIMATIC PCS 7 Advanced Process Library (APL), adding auxiliary actuator diagnostics (such as Valve Jammed, Loss of Control, Torque Alarm, Operating Hours, and Remote Feedback) to the VlvMotL valve-motor block without altering certified base library code is accomplished using three standard design patterns: (1) the APL multi-instance faceplate technique, (2) faceplate jump buttons using parameters SelFp1 and SelFp2, or (3) encapsulating VlvMotL with auxiliary blocks into a custom Control Module Type (CMT) or hierarchy folder. Connecting auxiliary Foundation Fieldbus or PROFIBUS PA diagnostic signals to user inputs (UserStatus) or companion blocks allows WinCC faceplates to expose comprehensive motor and valve telemetry.

Actuator Diagnostic Requirements Beyond Standard VlvMotL I/O

In modern process plants, motorized valves, MOV actuators (such as Rotork, Limitorque, or Auma), and intelligent motor control centers provide extensive fieldbus telemetry over Foundation Fieldbus or PROFIBUS DP/PA:
* Standard VlvMotL Scope: The standard APL VlvMotL block provides core valve-motor control: Open/Close commands, Open/Close limit switch feedback, thermal overload, and basic runtime monitoring.
* Auxiliary Field Diagnostics: Field actuators frequently report specialized operational conditions:
1. Valve Jammed / High Torque Alarm: Mechanical obstruction during stroke.
2. Loss of Control / Local Selector Switch: Field actuator placed in local manual mode.
3. Operating Hours and Operation Counters: Mechanical wear tracking for preventative maintenance.
4. Torque Switch Trip: Torque limit exceeded before reaching travel limit switch.
* Because modifying the internal SCL code of certified APL library blocks invalidates vendor support, engineers must utilize modular extension techniques.

APL Multi-Instance Faceplate Architecture and Styleguide Rules

The Siemens APL Styleguide defines the Multi-Instance Faceplate technique as the primary method for consolidating complex equipment telemetry into a single operator window:

Operating Principle:
An operator faceplate can embed multiple sub-faceplates into tabbed views or auxiliary views.
For example, the main view displays VlvMotL for start/stop control, while a secondary tab embeds CountOh (Operating Hours Counter) and MonDiL (Digital Monitoring for Torque Alarms).
Implementation Steps:
1. In CFC, instantiate VlvMotL alongside companion monitoring blocks (CountOh, MonDiL).
2. Open Graphics Designer on the Engineering Station: open @PG_VlvMotL_Standard.PDL.
3. Save the modified picture with a project-specific prefix (e.g., @PG_VlvMotL_Custom.PDL) in the local OS project folder.
4. Embed an additional tab or status icon mapped to the companion block's OS tag name using the #Jump script logic.

Configuring Auxiliary Block Jumps Using SelFp1 and SelFp2

The simplest, zero-coding method to link auxiliary blocks to VlvMotL is utilizing the native APL button jump parameters:

Parameter Interconnection in CFC:
* Locate parameters SelFp1 and SelFp2 on the VlvMotL block interface.
* Interconnect SelFp1 to the output of an auxiliary diagnostic block, such as CountOh.Out (Operating Hours).
* Interconnect SelFp2 to a digital alarm block, such as MonDiL.Out (Torque Switch Trip).
OS Compilation Tag Generation:
* When the OS compiles, the AS-OS compiler detects the interconnections and generates internal WinCC tags: VlvMotL.SelFp1#Jump and VlvMotL.SelFp2#Jump.
Faceplate Runtime Navigation:
* In WinCC Runtime, opening the VlvMotL faceplate reveals dynamic navigation buttons in the toolbar.
* Clicking the button opens the dedicated faceplate of the operating hours counter or torque monitor directly adjacent to the valve faceplate.

Creating Custom Composite Control Module Types (CMT) in CFC

Starting in PCS 7 V8.1 and V8.2, Control Module Types (CMT) in the Master Data Library provide the preferred engineering framework:

Encapsulating Actuator Logic:
In the Master Data Library, create a CMT named CMT_MOV_Actuator.
Place VlvMotL as the primary technological block.
Add CountOh for tracking total operating hours and stroke count.
Add two MonDiL blocks for Torque_Open and Torque_Close alarms.
Interconnect the status outputs to VlvMotL.UserStatus to display alarm badges directly on the valve block icon.
Mass Instantiation:
Instantiating the CMT across hundreds of plant valves automatically configures all interconnections, alarms, and block icon badges with 100% uniformity.

Comparison of Actuator Faceplate Customization Techniques

The table below compares methods for extending APL block faceplates with auxiliary actuator diagnostics.

Customization MethodEngineering EffortUpgradability During PCS 7 MigrationOperator ExperienceRequires WinCC PDL Edits?Button Jumps (SelFp1/SelFp2)Minimal (CFC wiring only)100% Migration-ProofOpens linked faceplate in 1 clickNoControl Module Type (CMT)Low to ModerateHigh (Template-based)Unified icon badges & alarmsNoMulti-Instance FaceplateHigh (Custom PDL scripting)Moderate (Requires PDL re-check)All data on single tabbed windowYesModifying Base APL SCL CodeHighProhibited (Zero upgradability)SeamlessNo

Verification

To confirm that auxiliary actuator diagnostics function properly:
1. In CFC, verify that VlvMotL.SelFp1 is interconnected to CountOh.Out and SelFp2 is connected to MonDiL.Out.
2. Compile and download CFC charts and compile the OS.
3. In WinCC Runtime, click the customized valve block icon to open the VlvMotL faceplate.
4. Verify that two navigation buttons appear in the faceplate header.
5. Click Button 1: confirm that the CountOh faceplate opens immediately, displaying total operating hours and stroke count.
6. Trigger a torque fault in the field: verify that MonDiL generates a process alarm and flags the condition on the operator display.

Limitations and Operational Precautions

Never overwrite system PDL files in the PCS 7 installation directory (\Siemens\WinCC\Options\PDL\); always place customized faceplate files in the local OS project GraCS directory.
Avoid packing excessive custom dynamic scripts into cyclic screen events; use tag triggers or APL standard dynamic dialogs to maintain client performance.
When migrating to future PCS 7 versions, customized PDLs must be reconciled against updated APL faceplate templates using the OS Project Editor.
Always validate final software licensing, APL library versions, and device integration packages against the applicable Siemens catalog and authorized distributor quotation.

Engineer FAQ

Why does VlvMotL lack native inputs for torque switches?

Because APL follows a modular architecture where base blocks handle core control, and specialized requirements (torque, thermal overload, power consumption) are handled by modular satellite blocks like MonDiL and CountOh.

How do I show an alarm badge on the valve block icon for torque fault?

Connect the output of MonDiL to one of the external error inputs (ExtErr or ExtMsg1) of VlvMotL; the block icon will automatically display a flashing alarm bell icon upon trip.

Can I customize the label on the SelFp1 button?

Yes. Configure the OS additional text property on parameter SelFp1 in CFC, which generates the #OS_Text tag in WinCC to label the faceplate button.