Converting an Engineering Station (ES) to an OS Client in SIMATIC PCS 7: Licensing and Project Configuration

To convert an existing SIMATIC PCS 7 Engineering Station (ES) into an operational OS Client, you do not need to reinstall the operating system or PCS 7 software because the ES installation already contains all necessary WinCC client binaries. However, you must procure and install runtime licenses via Automation License Manager (ALM), including the SIMATIC PCS 7 OS Software Client license (e.g., 6ES7658-2CX28-0YB5 for V8.2) and any client visualization options (such as SFC-Visualization or Safety Matrix Viewer). In the STEP 7 multiproject, reconfigure the PC Station object by replacing the WinCC Application with a 'WinCC Appl. Client', assign the target computer name, load OS Server packages, and download the client project.

Architectural Feasibility: ES Software Superset vs Client Runtimes

In industrial plants modernizing their automation topology, surplus engineering hardware—such as a secondary commissioning laptop or spare Engineering Station (ES)—is frequently repurposed as an active Operator Station (OS Client) on the plant floor. A frequent question from automation engineers is whether converting an ES requires formatting the PC and performing a fresh installation from the OS Client media.

In SIMATIC PCS 7, the Engineering Station software installation is a complete functional superset of the OS Client. Every background DLL, WinCC runtime graphic control, communication channel, and terminal bus service required by an OS Client is already present on an ES installation. Therefore, physical reinstallation of Windows or PCS 7 is completely unnecessary; the transformation is accomplished strictly through runtime license allocation and project object reconfiguration.

Mandatory Runtime Licensing for Converted OS Clients

While the software binaries exist on disk, licensing models for engineering and runtime are legally and technically segregated in Siemens Automation License Manager (ALM):

The ES License Boundary: The base SIMATIC PCS 7 Engineering Toolset license authorizes engineering tools (STEP 7, CFC, SFC, WinCC RC/CS, IEA, PDM). It does NOT grant runtime rights to operate as an active plant-floor operator station receiving server data packages.
Mandatory OS Client License: To operate as a production client, the station must possess the orderable runtime license:
SIMATIC PCS 7 OS Software Client (e.g., MLFB 6ES7658-2CX28-0YB5 for PCS 7 V8.2).
Optional Operator Add-Ons: If the converted client will execute specialized visualization faceplates identical to other control room desks, install matching add-on licenses:
SIMATIC PCS 7 SFC-Visualization (MLFB 6ES7652-0XD28-2YB5)
SIMATIC PCS 7 Logic Matrix Viewer
SIMATIC Safety Matrix Viewer

Hardware and Station Configuration in Station Configuration Editor

On the physical PC being converted:

Open the Station Configuration Editor from the Windows taskbar.
Ensure the station name matches the exact Windows computer hostname.
In the virtual rack (typically Slot 1), the station will have an Application or WinCC Appl. component. When operating purely as a client, the Station Configuration Editor can host Application without requiring specialized CP 1623 communications processors, as all client-to-server traffic is routed over standard commercial network adapters on the Terminal Bus.

STEP 7 Multiproject Reconfiguration and WinCC Client Project Creation

In SIMATIC Manager on the primary Master ES:

Navigate to Component View. In the multiproject tree, locate the PC Station corresponding to the second machine.
If previously configured as an ES with a standard OS, open HW Config for that station. Delete the WinCC Appl. in Slot 1 and insert a WinCC Appl. Client from the hardware catalog (SIMATIC PC Station -> HMI -> WinCC Appl. Client).
Save and compile HW Config.
In SIMATIC Manager Component View, expand the new client object and open the OS Client project in WinCC Explorer.
Open Server Data; right-click, select Load..., and select the server data package (*.pck) generated by the redundant OS Server pair.
Run the OS Project Editor to apply standard screen resolutions, monitor layouts, and system picture templates (@screen.pdl).

Comparative Architecture Matrix: Dedicated ES vs Standalone OS Client vs Converted ES

The following table compares configuration requirements across station types:

Engineering DimensionDedicated Engineering StationDedicated Factory OS ClientConverted ES Operating as OS ClientInstalled SoftwarePCS 7 Engineering ToolsetPCS 7 OS Client OnlyPCS 7 Engineering Toolset (Retained)Required ALM LicensesPCS 7 Engineering Toolset, AS POPCS 7 OS Software ClientPCS 7 OS Software Client (Added)WinCC Application TypeWinCC Appl. (or Single Station)WinCC Appl. ClientWinCC Appl. ClientNetwork Bus AttachmentPlant Bus & Terminal BusTerminal Bus OnlyTerminal Bus Only (Plant Bus disconnected)Process Object AccountingDynamically tracks AS POs0 POs consumed0 POs consumed (Client queries Server)Download MechanismMultiproject Master HostTarget Download from Master ESTarget Download from Master ES

Step-by-Step Conversion and Commissioning Workflow

Follow this sequence to complete the conversion cleanly:

Isolate Network: Disconnect the converted station from the Plant Bus (Industrial Ethernet). Connect it exclusively to the Terminal Bus.
Install Client Licenses: Using Automation License Manager (ALM), transfer the PCS 7 OS Software Client license and any required add-on licenses to drive C:.
Reconfigure Multiproject: On Master ES 1, configure the PC Station as WinCC Appl. Client, assign the exact computer name, and link Server Data.
Download Client Project: In SIMATIC Manager, right-click the OS Client object and select PLC -> Download to transfer the client runtime configuration across the Terminal Bus to the target PC.
Activate Runtime: On the converted station, open WinCC Runtime. Confirm that all plant pictures, alarms, and faceplates load seamlessly.

Verification

Verify operational readiness of the converted OS Client:

Open Automation License Manager on the converted PC; execute Check Licenses and confirm that PCS 7 OS Software Client displays status 'Valid' without missing license popups.
Activate WinCC Runtime; confirm that process values update smoothly across all graphic screens.
Open an analog motor or valve faceplate; verify full operator control and command interlocks.
Open the Alarm Logging banner; verify that live alarms appear with correct timestamps from the primary OS Server.

Limitations and Operational Precautions

Adhere to the following architectural precautions:

Never Operate Dual ES Masters Simultaneously: If the converted PC retains engineering software, ensure engineers do not open or download CFC charts from this station while Master ES 1 holds the multiproject; multiproject cross-references will become desynchronized.
Physical Plant Bus Disconnection: Physically disconnect or disable any CP 1623 cards in the converted PC; OS Clients must communicate exclusively via the Terminal Bus to avoid network loopbacks.
Commercial License Validation: Always procure genuine Siemens runtime licenses prior to putting a converted workstation into production.

[!NOTE]
Commercial Accuracy Disclaimer: Software order numbers (MLFBs), package structures, and hardware capacity prerequisites vary across PCS 7 versions > and hardware platforms. System integrators must confirm exact software entitlements and licensing requirements against the official Siemens > Catalog CA 01 and obtain an authorized Siemens distributor quotation prior to purchasing.

Engineer FAQ

Can the converted OS Client still be used for engineering in an emergency?

Yes, if the ES engineering licenses remain installed in ALM, you can close WinCC Runtime and open SIMATIC Manager. However, you must avoid downloading to PLCs unless the project is properly synchronized with the Master ES.

Do OS Clients consume AS Process Object (AS RT PO) licenses?

No. OS Clients query data from OS Servers via Server Data packages and do not consume any AS or OS Process Object runtime licenses.

Should the converted station remain connected to the Plant Bus?

No. Operating OS Clients must communicate exclusively over the Terminal Bus. Physically disconnect or disable the Plant Bus adapter to prevent network routing conflicts.