Repurposing a SIMATIC PCS 7 OS Client Station as an Engineering Station (ES) - Architecture, Hardware, and Software

Repurposing an existing SIMATIC PCS 7 OS Client PC into an Engineering Station (ES) is technically possible, but it requires a complete software rebuild, hardware resource upgrades, and communications processor installation. An OS Client typically lacks the CPU performance, RAM capacity (often 2–4 GB vs 8–16 GB required for an ES), and dual-bus network architecture of an ES. Furthermore, STEP 7 must be installed before WinCC to configure the AS-OS engineering database; installing engineering tools over an existing OS Client image will corrupt component registration. The required engineering licenses (STEP 7, CFC, SFC, WinCC RC) and Industrial Ethernet communication processors (CP 1613 or CP 1623) must be transferred from the decommissioned ES.

Architectural Differences Between OS Client and Engineering Station

In a SIMATIC PCS 7 plant architecture, the operational roles and system loads of an OS Client and an Engineering Station (ES) differ substantially. Understanding these differences explains why converting an OS Client requires comprehensive reconfiguration:

System DimensionSIMATIC PCS 7 OS ClientSIMATIC PCS 7 Engineering Station (ES)Primary Operational RoleVisualization runtime client accessing OS Server packagesCentral multiproject repository, AS/OS compilation masterNetwork TopologySingle network interface connected to Terminal BusDual network interfaces: Terminal Bus and Plant BusAS Communication InterfaceNone (receives process data indirectly via OS Server)Dedicated Industrial Ethernet processor (CP 1613 / CP 1623) or BCEInstalled Software SuiteWinCC Runtime Client (RT Client), Simatic ShellSTEP 7, CFC, SFC, SCL, WinCC RC, AS-OS Engineering, SIMATIC LogonTypical Hardware SizingDual-core CPU, 2 GB to 4 GB RAM, standard storageQuad-core / Xeon CPU, 8 GB to 16+ GB RAM, high-speed storageLicensing FrameworkWinCC RT Client licenseSTEP 7, CFC, SFC, WinCC RC (Complete), Engineering Tool licenses

An OS Client functions as a lightweight display console, whereas an Engineering Station hosts heavy SQL Server database engines, compilers, and communication layers capable of downloading code directly to running automation controllers.

Hardware Assessment and Sizing Requirements

Before attempting to convert an existing OS Client chassis (such as a SIMATIC IPC427 Microbox or IPC547 desktop) into an Engineering Station for PCS 7 V7.0, conduct a thorough hardware audit:

RAM Expansion: PCS 7 V7.0 Engineering Stations require a minimum of 2 GB to 4 GB RAM (or 8 GB on modern releases). If the spare OS Client has only 1 GB or 2 GB, transfer RAM modules from the decommissioned ES or install compatible industrial ECC RAM.
Processor Performance: Heavy chart compilation (CFC/SFC) and OS database generation place intense loads on the CPU. Verify that the processor meets or exceeds the processing speed of the old ES.
Industrial Ethernet Communications Processor (Plant Bus): If the PCS 7 plant utilizes ISO Transport protocol across Industrial Ethernet to communicate with S7-400 AS controllers, the ES must be equipped with a dedicated communications processor card. Physically remove the CP 1613 (PCI) or CP 1623 (PCIe) card from the failed ES and install it into an available expansion slot on the repurposed client PC. If standard TCP/IP with Basic Communication Ethernet (BCE / Softnet-IE) is used, ensure a compatible Intel network adapter is installed.
Terminal Bus Network Adapter: A second network adapter is mandatory so the ES can connect to the Terminal Bus for loading runtime data to OS Servers and OS Clients.

Step-by-Step Procedure to Convert an OS Client into an ES

Attempting to install STEP 7 or engineering packages on top of an existing OS Client Windows installation causes fatal registry and COM component registration conflicts. The installation must be executed cleanly from bare metal:

Audit and Harvest Hardware Components: Power down both machines. Remove the CP 1613/CP 1623 communications card and extra RAM modules from the decommissioned ES. Install them securely into the target OS Client chassis.
Perform Clean Operating System Reinstallation: Format the primary hard drive completely. Install a fresh instance of the certified Windows operating system (for PCS 7 V7.0, Windows XP Professional SP2/SP3 or Windows Server 2003, depending on system release).
Assign Permanent Computer Name and Network Settings: Before installing any Siemens software, set the permanent Windows Computer Name in System Properties (e.g., ES_STATION_01). Critical Rule: A PCS 7 station must never be renamed after software installation. Assign static IP addresses to both the Plant Bus and Terminal Bus network adapters.
Install SIMATIC PCS 7 Engineering Station: Insert the official SIMATIC PCS 7 V7.0 Installation DVD. In the setup wizard, select Package Installation -> Engineering Station. The setup program automatically installs software in the mandatory sequence: STEP 7 core, followed by CFC, SFC, SCL, WinCC (Complete RC), AS-OS Engineering, and SIMATIC NET.
Configure Communication Layers: Open the Station Configuration Editor. Add the CP 1613 / CP 1623 and WinCC Application components matching the ES hardware configuration in SIMATIC Manager. Open Set PG/PC Interface and bind the access points (S7ONLINE, PC Internal) to the active industrial Ethernet adapter.
Transfer Engineering Licenses via ALM: Connect the license USB dongle or open Automation License Manager (ALM) to transfer the required engineering licenses: STEP 7, CFC, SFC, WinCC RC (complete), and SIMATIC Logon from the old ES backup or original license keys.

Verification

Verify that the converted Engineering Station operates with complete architectural integrity:

Station Configuration Editor Status: Open the Station Configuration Editor. Verify that the CP 1613/CP 1623 card and the WinCC Application show run status with green indicators and zero configuration faults.
Multiproject Retrieval and Consistency: In SIMATIC Manager, select File -> Retrieve and extract the latest multiproject backup. Open HW Config and CFC charts. Execute Chart -> Check Consistency -> Entire Program; confirm 0 Errors.
Online AS Connectivity: In SIMATIC Manager, select an AS 400 controller object and click PLC -> Diagnostic/Setting -> Operating Mode. Verify that the ES establishes live communication and displays controller status.
Trial OS Compilation: Execute an OS compilation (Compile OS -> Changes Only). Verify that AS-OS Engineering compiles tag management and alarm logging records without SQL database errors.

Limitations and Operational Precautions

Observe these critical technical, operational, and commercial guardrails when repurposing PCS 7 stations:

Never Install STEP 7 Over an OS Client Image: Siemens AS-OS Engineering relies on shared COM and SQL interfaces installed during initial setup. Installing STEP 7 after WinCC runtime is already installed corrupts the AS-OS database link.
Physical Slot Compatibility: Ensure the OS Client chassis has the appropriate physical bus slot (PCI 32-bit for older CP 1613 vs PCIe x1/x4 for CP 1623). Forcing cards into incompatible slots will damage hardware.
Commercial Accuracy Notice: Operating an Engineering Station requires distinct engineering software licenses (STEP 7, CFC, SFC, WinCC RC). OS Client runtime licenses (WinCC RT Client) cannot be legally or technically substituted for engineering tools. Always verify license entitlements, upgrade options, and MLFBs with an authorized Siemens representative before commissioning.

Engineer FAQ

Can I just uninstall WinCC Client and install the ES software without wiping Windows?

This is strongly discouraged. Uninstalling WinCC leaves orphaned registry entries, SQL database instances, and shared DLLs that frequently cause silent compilation failures during future AS-OS engineering tasks. A clean OS format is the only reliable method.

Can I use a standard commercial Ethernet card for the Plant Bus instead of a CP 1613/1623?

If the plant uses standard TCP/IP communication, an approved Intel PRO/1000 network card can be used with Softnet-IE BCE (Basic Communication Ethernet). However, if the plant uses ISO Transport protocol for deterministic AS-OS communication, a CP 1613 or CP 1623 is mandatory.

Does repurposing a client PC affect the remaining plant network?

No. The remaining OS Servers and OS Clients will continue to operate normally. The newly built ES will only communicate with the plant when an engineer initiates an online monitor, chart compile, or download sequence.