Multi-Monitor Configuration Limits and Displaying 6 Screens on PCS 7 WinCC OS Clients

In SIMATIC PCS 7 OS (WinCC V7.x through V7.5 in PCS 7 V9.0 / V9.1), the built-in OS Project Editor natively supports multi-monitor arrangements up to a maximum of 4 screens (Quad-Monitor layout). To operate 6 displays at a single operator console, engineers must combine hardware multi-head display spanning (such as NVIDIA Mosaic technology merging displays into unified desktop viewports), deploy dual OS Clients at the operator desk, or run supplementary sessions via PCS 7 Web Navigator.

Executive Summary

Modern industrial control rooms frequently demand expansive visual overviews, requiring operators to monitor overview graphics, detailed skid schematics, alarm sequences, and trend charts simultaneously across five or six physical displays. Automation engineers configuring SIMATIC PCS 7 V8.2, V9.0, or V9.1 often seek to extend the workstation display layout beyond standard quad-monitor setups.

However, opening the OS Project Editor in WinCC Explorer reveals that native monitor layout options are strictly capped at Quad-Monitor configurations (1x1, 1x2, 2x1, 2x2, 1x3, 1x4, 4x1). The underlying Split Screen Manager (SSM) architecture and screen coordinate calculation algorithms were engineered around a four-monitor ceiling. This guide explains the architectural boundaries of the OS Project Editor, evaluates commercial multi-display hardware options, and outlines proven engineering strategies to deploy 6-screen control room consoles safely.

Architecture and Fundamental Mechanics

The PCS 7 HMI visualization framework is managed by the Split Screen Manager (SSM) and initialized via the OS Project Editor. The system architecture involves several interacting components:

OS Project Editor Display Division: During OS compilation and project generation, the OS Project Editor populates screen navigation pictures (@Screen.pdl, @Overview1.pdl, @Button11.pdl) with layout-specific coordinates. It supports single, dual, triple, and quad monitor configurations. The internal coordinate database stores monitor bounding boxes as discrete logical rectangles numbered 1 through 4.
The 4-Monitor Ceiling: The native SSM C-scripts (SSMGetScreen..., SSMOpenTop...) contain hardcoded array limits indexing up to 4 display units. Attempting to force higher monitor counts inside the project editor is rejected by the GUI, and manually altering the project configuration database causes runtime script errors in SCRIPT.EXE.
Hardware Spanning (NVIDIA Mosaic / AMD Eyefinity): Rather than presenting 6 individual display outputs to the operating system, professional workstation GPUs (such as NVIDIA RTX / Quadro series) allow grouping physical screens at the driver level. For example, six 1920x1080 monitors can be grouped into two 3x1 spanned virtual surfaces of 5760x1080 resolution. WinCC perceives only two high-resolution monitors, which easily conforms to standard dual-monitor OS Project Editor settings.
Dual-Client Architecture: In high-reliability operations, installing two independent OS Client IPCs side-by-side (each driving 3 displays or one driving 4 and one driving 2) eliminates single-point-of-failure risks: if one client workstation reboots, the operator retains 100% control over the remaining screens.

Step-by-Step Implementation Procedure

Follow these steps to implement a 6-screen operator station architecture for SIMATIC PCS 7:

Approach A: Hardware Display Spanning (Recommended for Single Workstation)
1. Procure and Install Multi-Head Workstation Hardware:
- Equip the OS Client IPC with a certified multi-output professional GPU (e.g., NVIDIA Quadro P4000/RTX A4000 with 4 DisplayPort outputs, or dual synchronized GPUs).
- Connect all 6 physical monitors using active DisplayPort to HDMI/DVI adapters or direct DP cables.

Configure NVIDIA Mosaic in Windows:
- Open the NVIDIA Control Panel.
- Navigate to 'Workstation' > 'Set up Mosaic'.
- Group the displays into spanned configurations supported by the OS Project Editor. For example, configure two virtual displays where Virtual Screen 1 spans the top row of 3 monitors (5760x1080) and Virtual Screen 2 spans the bottom row of 3 monitors (5760x1080).
- Apply the configuration: Windows Display Settings now detects a 2-monitor desktop.
Configure OS Project Editor in WinCC Explorer:
- Open the OS Client project in WinCC Explorer.
- Double-click 'OS Project Editor'.
- Switch to the 'Layout' tab.
- Select the layout matching your spanned virtual topology (e.g., 'SIMATIC standard 16:9' with 'Dual Monitor 1x2' or custom resolution).
- Click 'OK' to regenerate the screen hierarchy.

Approach B: Dual-Client Console Architecture (Recommended for High Availability)
1. Configure Two OS Clients in SIMATIC Manager:
- Insert two OS Client stations (e.g., OS_CLT01 and OS_CLT02) into the PCS 7 multiproject.
- Assign 3 physical monitors to Client 1 and 3 physical monitors to Client 2 (using Triple Monitor layout in OS Project Editor).
- Place both client IPCs in the same operator console desk, using a unified multi-system keyboard/mouse sharing solution (or separate input devices).

Approach C: Web Navigator Auxiliary Displays
1. Use a standard Quad-Monitor OS Client for the main 4 process control screens.
2. Dedicate the 5th and 6th screens to supplementary browser-based PCS 7 Web Navigator sessions, Long-Term Trend displays, or Process Historian Information Server dashboards.

Verification

Power on the OS Client and verify that the Windows desktop spans smoothly across all 6 monitors without resolution tearing or aspect ratio distortion.
Activate WinCC Runtime. Confirm that overview areas, button bars, and alarm message lines align correctly on the designated display rows.
Open APL faceplates from various process mimic diagrams. Confirm that pop-up faceplates open within the visual boundaries of the originating monitor rather than clipping across monitor bezels.
Trigger an alarm and verify that audible alerts and message banners respond instantly across all display segments.

Limitations and Operational Precautions

Directly modifying internal WinCC Split Screen Manager scripts to force native 6-monitor management is unsupported by Siemens Customer Support and will be overwritten during any subsequent OS Project Editor run. Spanned hardware displays require high-performance graphics hardware and identical monitor resolutions and refresh rates. Verify industrial IPC specifications and licensing with an authorized Siemens distributor or the Siemens Industry Mall.

Engineer FAQ

Does PCS 7 V9.1 support 6 monitors natively in OS Project Editor?

No. The native OS Project Editor in PCS 7 V9.0 and V9.1 remains limited to a maximum of 4 monitors (Quad-Monitor configuration).

What graphics card technology enables spanning 6 screens as 2 monitors?

NVIDIA Mosaic technology (available on NVIDIA Quadro and RTX professional GPUs) combines multiple physical monitors into unified virtual surfaces at the driver level.

Can I run 6 monitors by using two 3-monitor graphic cards without Mosaic?

If configured as 6 separate Windows desktop displays, the WinCC OS Project Editor will not be able to manage the layout natively. You must use driver-level spanning or multiple WinCC runtime instances.

Do multi-monitor OS Clients consume extra WinCC licenses?

No. A PCS 7 OS Client license (SIMATIC PCS 7 OS Client) authorizes the client workstation regardless of whether it drives 1, 2, 3, or 4 monitors.

What layout does Siemens recommend for a 6-screen control console?

Siemens generally recommends deploying two redundant OS Clients (each operating 3 screens) to provide physical workstation redundancy and simplify layout management.