Preventing Block Icon Layer Reset to Layer 0 During Create and Update Block Icons

In SIMATIC PCS 7 V9.0, running 'Create/Update Block Icons' resets all block icon graphics in process pictures to Layer 0 because the generation routine applies properties from the master template icons in @PCS7TypicalsAPLV9.pdl. If the master template icon resides on Layer 0, the generator overwrites any local layer assignment (Layers 1-31) in the target process graphic. To permanently assign block icons to a specific layer, save a copy of the typicals file as @PCS7TypicalsAPLV9_Custom.pdl, change the Layer property of the master block icon template to the desired layer, and re-run 'Create/Update Block Icons' from SIMATIC Manager.

Create/Update Block Icons Mechanism and Master Template Inheritance

In SIMATIC PCS 7, the Create/Update Block Icons wizard (Plant Hierarchy -> Create/Update Block Icons) automates the generation and positioning of HMI symbols across WinCC process mimic screens (*.pdl). When an engineer creates technology blocks in CFC (such as motors, valves, or analog monitors), the wizard reads the block configuration and copies the corresponding graphic symbol from the master template picture into the target process display.

Crucially, the update routine does not merely update tag interconnections; it synchronizes graphic object properties—including geometry, fonts, custom properties, and display Layer assignments—from the source template picture (@PCS7TypicalsAPLV9.pdl). If an engineer manually organizes block icons onto specific display layers (e.g., Layer 5 for instrumentation and Layer 10 for electrical) in the process screen, running the update wizard forcibly overwrites those local layer assignments with the layer defined in the typical template.

Root Cause Analysis - Typicals Layer Hierarchy vs Picture Layers

WinCC Graphics Designer supports 32 distinct display layers (numbered 0 to 31). Engineers utilize layers to organize screen complexity, allowing background piping to sit on Layer 0 while dynamic block icons reside on higher layers that can be hidden or locked during graphic editing.

In standard Siemens typical files (@PCS7TypicalsAPLV9.pdl), virtually all baseline block icons are positioned on Layer 0. When the PCS 7 generator processes an icon update, it evaluates the template object: because the template resides on Layer 0, the generator writes Layer = 0 to the destination object attribute. To retain a custom layer across repeated compilations, the layer property must be modified at the source template level.

Layer Architecture and Typicals Precedence Matrix

The table below details template file loading priority, layer behavior, and update persistence in SIMATIC PCS 7:

Template FileLoading PrecedenceSystem Update ImpactLayer Persistence Behavior@PCS7TypicalsAPLV9_Custom.pdlPriority 1 (Highest)Immune to PCS 7 updatesRecommended: Custom layer assignments defined here persist across all updates.@PCS7TypicalsAPLV9.pdlPriority 2 (Standard)Overwritten by OS Project EditorEdits to Layer 0 are wiped upon applying library updates or running OSPE.@TemplateAPLV9.pdlFallback / ReferenceOverwritten by library setupStatic reference file; not processed by Create/Update Block Icons.Target Process Picture (*.pdl)DestinationOverwritten by Typical GeneratorLocal manual layer edits are wiped whenever Update Block Icons is executed.

Step-by-Step Procedure to Preserve Custom Block Icon Layers

Create Custom Typicals Picture:
- In WinCC Explorer, open Graphics Designer.
- Open the standard typicals template @PCS7TypicalsAPLV9.pdl.
- Select File -> Save As... and name the file @PCS7TypicalsAPLV9_Custom.pdl in the GraCS directory. PCS 7 automatically prioritizes files ending in _Custom.pdl.
Assign Target Layers in Custom Typicals:
- In @PCS7TypicalsAPLV9_Custom.pdl, enable the Layer Palette toolbar (View -> Toolbars -> Layer Palette).
- Select the target master block icons (e.g., select all valve and motor icons).
- In the Layer Palette or the Object Properties (Properties -> Geometry -> Layer), change the layer assignment from 0 to the desired target layer (e.g., Layer 5).
- Save and close @PCS7TypicalsAPLV9_Custom.pdl.
Execute Update Block Icons:
- In SIMATIC Manager, right-click the OS project or plant hierarchy folder.
- Select Plant Hierarchy -> Create/Update Block Icons....
- Select the affected process screens and click OK.
Verify Layer Assignment: Open the updated process picture in Graphics Designer: confirm that all generated block icons now reside cleanly on Layer 5.

Verification

Verify persistent layer behavior through the following milestones:
1. In Graphics Designer, open the target process screen.
2. Open the Layer Palette and toggle Layer 5 visibility off: verify that the block icons disappear while background piping on Layer 0 remains visible.
3. Add a new block in CFC, re-run 'Create/Update Block Icons': verify that the new icon is created directly on Layer 5 without disturbing existing screen elements.

Limitations and Operational Precautions

Always verify that all 32 layers are set to visible in the WinCC Runtime computer properties (Computer Properties -> Graphics Runtime -> Display Layers). If a layer is hidden in runtime properties, block icons generated on that layer will be invisible to operators during live plant operation. Additionally, keep layer assignments consistent across all custom typical files to ensure uniform project maintainability.