How to Prevent Unintended Valve Orientation Flipping Between Horizontal and Vertical in PCS 7 APL Block Icons

In SIMATIC PCS 7 Advanced Process Library (APL) V8.0 and V8.1, the issue where a valve block icon (such as VlvL or VlvMotL) unexpectedly flips its visual orientation from horizontal to vertical in WinCC SCADA when an Open command is issued is caused by the default multi-state graphic feature in '@PCS7TypicalsAPLV8.pdl'. In APL V8, variant 1 of the valve block icon is designed to visually rotate or change direction to indicate open flow paths. To maintain a static horizontal or vertical orientation regardless of operational state, engineers must assign a specific block icon variant number (e.g., 'type = 2' or 'type = 3') in the CFC block properties or revert to static block icon templates from '@PCS7TypicalsAPLV7.pdl'.

Mechanics of Dynamic Valve Orientation in @PCS7TypicalsAPLV8.pdl

In PCS 7 APL V8.0, Siemens introduced modernized graphical representations:
* The Dynamic Flow Indicator Feature:
* In template file @PCS7TypicalsAPLV8.pdl, the default variant (Variant 1) of the motorized valve block icon was engineered with dynamic orientation changes.
* When the valve is Closed, the symbol renders horizontally with red/gray closed wedges.
* When the valve is commanded Open, the internal dynamic script changes the bitmap or polygon angle to vertical to simulate flow opening!
* The Plant Confusion:
* In a piping and instrumentation diagram (P&ID), pipes run fixed in physical space.
* Having a valve suddenly flip from horizontal to vertical makes it appear as though the physical pipe disconnected, causing severe operator distraction and alarm confusion.

Understanding Template Search Order (@PCS7TypicalsAPLV8 vs V7)

When the engineer executes Compile OS (or runs Create/Update Block Icons):

Alphanumerical Template Hierarchy:
WinCC searches for typical templates in the OS project GraCS directory in strict alphanumerical order:
1. @PCS7TypicalsAPLV8.pdl
2. @PCS7TypicalsAPLV7.pdl
3. @PCS7Typicals.pdl (Classic)
Default Variant Selection:
If the engineer does not specify an explicit variant number in CFC, the AS-OS compiler automatically selects the lowest-numbered variant found in the first template encountered (Variant 1 of @PCS7TypicalsAPLV8.pdl).
In @PCS7TypicalsAPLV7.pdl, valve icons were strictly static; they changed color (green/gray/red) without altering physical screen orientation.

Configuring Block Icon Type Variants in Continuous Function Charts

The standard, zero-risk method to lock valve orientation is configuring an explicit variant number in CFC:

Inspect Available Variants in Graphics Designer:
* Open @PCS7TypicalsAPLV8.pdl in Graphics Designer.
* Locate the valve block icons (e.g., @VlvMotL/1, @VlvMotL/2, @VlvMotL/3).
* Select a variant that remains static (e.g., Variant 2 for horizontal static or Variant 3 for vertical static).
Assign Type Property in CFC:
* Open the CFC chart containing the valve block.
* Select the valve block (VlvMotL): right-click and choose Object Properties.
* Locate parameter Block icon:
- To select Variant 2: enter 2.
- To select Variant 3: enter 3.
Regenerate Block Icons:
* In SIMATIC Manager, select the plant hierarchy folder: Options > Plant Hierarchy > Create/Update Block Icons.
* WinCC replaces the dynamic flipping icon with the rock-solid static variant.

Creating Custom Static Block Icons in Graphics Designer

If a plant standard requires static icons across all valves without editing every CFC block:

Delete or Deprecate @PCS7TypicalsAPLV8.pdl:
* If APL V7 static icons are preferred site-wide, delete or rename @PCS7TypicalsAPLV8.pdl (e.g., to [email protected]).
* WinCC will automatically fall back to @PCS7TypicalsAPLV7.pdl, where all valve icons maintain static geometry.
Create Project Typicals (@Template.pdl):
* Alternatively, copy static valve icons into a custom project template: @PCS7TypicalsCustom.pdl.
* Because @PCS7TypicalsCustom.pdl precedes @PCS7TypicalsAPLV8.pdl alphabetically, the custom static icons take precedence globally.

Comparison of APL Valve Block Icon Variants and Behaviors

The table below outlines standard valve block icon variants in @PCS7TypicalsAPLV8.pdl.

Icon VariantIcon IdentifierGraphic Orientation BehaviorBest ApplicationVariant 1 (Default)@VlvMotL/1Dynamic (Flips Horizontal to Vertical)Dynamic flow diagrams (Not recommended for P&ID)Variant 2@VlvMotL/2Static Horizontal (Fixed angle)Standard horizontal pipe runsVariant 3@VlvMotL/3Static Vertical (Fixed angle)Standard vertical pipe runsVariant 4@VlvMotL/4Compact status badgeHigh-density overview screensAPL V7 Standard@PCS7TypicalsAPLV7Static Multi-Color (No rotation)Brownfield plant standard

Verification

To confirm that valve orientation is stable:
1. In CFC, configure VlvMotL parameter Block icon to 2.
2. Execute Options > Plant Hierarchy > Create/Update Block Icons.
3. In WinCC Runtime, locate the valve on the plant P&ID overview graphic.
4. Verify that the valve renders horizontally in the closed state.
5. Issue an Open command: verify that the valve symbol transitions to solid green (Opened) while remaining 100% horizontal without geometric rotation.
6. Issue a Close command: confirm that the valve returns to closed without orientation shifts.

Limitations and Operational Precautions

Never edit block icons directly on runtime process graphic files (*.pdl); any subsequent Create/Update Block Icons execution will overwrite manual edits from the master typicals file.
Always modify or declare variants inside @PCS7Typicals*.pdl files located in the project's local GraCS directory.
When executing OS Project Editor updates, verify that customized typical templates are protected from factory defaults.
Always validate final software licensing and system documentation against the applicable Siemens catalog and authorized distributor quotation.

Engineer FAQ

Why did Siemens design the valve icon to flip orientation in APL V8?

Siemens designed Variant 1 to visually simulate a 90-degree rotating plug/ball valve or diverter flow line. However, on fixed P&ID diagrams, this visual rotation is often confusing, requiring selection of Variant 2 or 3.

Where do I enter the variant number in CFC?

In CFC, double-click the block, open Object Properties, and type the variant number (e.g., 2) in the field labeled Block icon.

Can I customize the bitmap graphics inside the block icon?

Yes. In Graphics Designer, open the typical template, ungroup the block icon, replace the bitmap references in the Status display object, and re-group the icon.