Resolving SFC Faceplate Header Truncation and Clipping via Windows DPI Scaling

SFC faceplate header clipping in SIMATIC PCS 7 OS Runtime occurs when the operating system display DPI scaling is configured above 100% (e.g., 125% or 150%). WinCC Graphics Designer and PCS 7 faceplate container picture windows (@pg_@sfc_type and @pg_@sfc_type_head) utilize fixed-pixel coordinate geometry. When Windows display scaling is active, font metrics and dialog borders expand disproportionately, causing the header picture window to exceed its designated viewport. To permanently fix the clipping, set Windows display scaling to exactly 100% (Smaller - 100%) and sign out or restart the computer.

Root Cause of Faceplate Geometric Distortion

SIMATIC PCS 7 OS (WinCC) faceplates, including SFC Visualization, Advanced Process Library (APL) technological blocks, and CEMAT faceplates, are engineered using standard Windows Graphics Device Interface (GDI) controls. The parent faceplate window @pg_@sfc_type.pdl contains embedded picture windows (PictureWindow) with strict pixel width, height, and border offsets matching the child picture @pg_@sfc_type_head.pdl.

When Windows 10 or Windows Server 2016 operates on modern high-resolution monitors (e.g. 1920x1080 or 4K displays), Windows often automatically enforces 125% or 150% desktop scaling. Under high DPI, Windows dynamically rescales system fonts, button captions, and window frame borders, while WinCC picture window viewport containers remain bound to absolute pixel bounds. Consequently, child elements overflow and become clipped or partially hidden.

Symptoms of High-DPI Artifacts in WinCC Graphics

High-DPI misconfigurations manifest through several distinct graphical issues across the PCS 7 OS environment:

Header Truncation: The SFC type header (@pg_@sfc_type_head) clips mode selectors, step counters, and operating status fields.
Overlapping Faceplate Tabs: APL block faceplates display overlapping tab headers (Standard, Limit, Alarm, Trend, Parameter), rendering certain navigation tabs inaccessible.
Cut-off Alarm Control Columns: In @AlarmSelection.pdl, text inside alarm row columns becomes vertically truncated, cutting off date/time stamps and process tags.
Persistent Despite Project Editing: Running OS Project Editor, compiling with memory reset, or restoring pristine PDL templates from the library fails to correct the issue because the defect resides in the Windows desktop rendering subsystem.

Corrective Configuration Procedure

Execute the following steps to configure the Windows environment for SIMATIC PCS 7 compatibility:

Access Windows Display Settings:
- Right-click the Windows desktop and select Display Settings (or navigate to Control Panel > Appearance and Personalization > Display).
Set Display Scale to 100%:
- Under Scale and layout, locate the setting Change the size of text, apps, and other items.
- Change the selection from 125% or 150% to strictly 100% (Recommended / Smaller).
Enforce Resolution Standard:
- Ensure the display resolution matches the native screen aspect ratio configured in the WinCC OS Project Editor (e.g., 1920x1080 for standard widescreen layouts).
Log Off and Restart:
- Windows GDI font caching requires an active session restart. Sign out of Windows and log back in, or restart the workstation.

Display Scaling vs Faceplate Architecture Matrix

The table below contrasts system behavior under compatible versus non-compatible display settings:

Configuration ParameterCompatible Setting (100% Scaling)Incompatible Setting (>100% Scaling)Windows DPI Setting96 DPI (100% Default)120 DPI (125%) or 144 DPI (150%)SFC Faceplate HeaderPixel-perfect alignment inside picture windowClipped header, truncated text and controlsAPL Faceplate ViewsTab headers align neatly across title barOverlapping or wrapped navigation tabsWinCC AlarmControlFull text visible in all message columnsVertical font clipping and row height mismatchOS Project Editor ImpactScreen templates generate without offsetsGenerates graphics with distorted internal coordinatesSiemens System ReleaseOfficially tested and certifiedExplicitly unsupported in PCS 7 compatibility matrix

Verification

Verify proper graphics rendering after configuring display scaling:

Open WinCC Explorer and activate OS Runtime.
Navigate to a process graphic containing an SFC block icon and open the SFC faceplate.
Confirm that the header banner displays all status labels, mode indicators, and control buttons without border overlap.
Open an APL analog monitoring (MonAnL) and valve (VlvL) faceplate; confirm that tab selectors and limits align accurately.
Verify that Windows Display Settings confirms 100% on all monitors connected to multi-screen OS clients.

Limitations and Operational Precautions

Adhere to the following engineering precautions regarding OS station displays:

Multi-Monitor Homogeneity: In multi-screen operator stations, all monitors must be set to the identical resolution and 100% scaling. Differing DPI settings between monitors cause faceplate tearing when dragging windows.
Remote Desktop Sessions: When accessing OS stations via RDP or VNC, ensure the remote client client-side display scaling does not override the host session resolution.
Template Overwrites: Re-running the OS Project Editor will overwrite customized @pg_*.pdl files if they are not properly protected or customized via standard @Overview1.pdl hierarchy rules.

Engineer FAQ

Can I fix SFC faceplate clipping by resizing the @pg_@sfc_type_head picture window in Graphics Designer?

While manually resizing the picture window might provide temporary relief on one workstation, it corrupts the layout on standard 100% DPI stations and will be overwritten the next time the OS Project Editor is executed. The correct fix is setting Windows display scaling to 100%.

Why did replacing the PDL files with fresh copies from the library fail to solve the issue?

Because the library PDL files are designed with correct 96-DPI fixed pixel geometry. The truncation is caused by the Windows desktop font and window frame scaling engine, not by corrupted PDL source files.

How should 4K monitors be managed in PCS 7 OS environments?

To use 4K monitors (3840x2160) with PCS 7, ensure large physical displays (e.g. 32-inch or 43-inch) are used so that 100% scaling remains comfortable for operators. Alternatively, configure the graphics card resolution to 1920x1080 at 100% scaling.