Configuring Simatic Shell and Local OS Simulation Without a Physical PLC in PCS 7

To open Simatic Shell and run a SIMATIC PCS 7 OS project on a standalone engineering computer without a physical PLC, configure Simatic Shell to bind to an active local network adapter (or install the Microsoft KM-TEST Loopback Adapter), and simulate the controller using S7-PLCSIM. In Simatic Shell settings, designate the local adapter as the Terminal Bus interface, verify that encrypted communications settings match project requirements, and configure WinCC Tag Management to connect to PLCSIM via Named Connections or MPI/DP simulation channels.

Executive Summary

Automation engineers, commissioning specialists, and operators frequently need to run, test, or modify PCS 7 OS graphics and alarm systems on a portable engineering laptop outside the plant environment, where physical S7-400 controllers and plant bus switches are unavailable. Opening an OS project or Simatic Shell on a disconnected laptop often leads to network adapter binding errors, red cross icons in Simatic Shell, or WinCC Runtime connection failures. This article provides the definitive engineering procedure to configure Simatic Shell, network loopback adapters, and S7-PLCSIM for complete offline simulation.

Architecture and Fundamental Mechanics

Simatic Shell Network Architecture and Standalone Simulation Mechanics:

Role of Simatic Shell:
Simatic Shell is the core Windows Explorer shell extension responsible for terminal bus discovery, PC station synchronization, and redundant OS pair health monitoring.
It requires a functional, bound network interface with an assigned IP address to initialize its network daemon.
When a laptop is unplugged from the network, physical Ethernet adapters enter a 'media disconnected' state, causing Simatic Shell to fail initialization.
The Loopback Adapter Solution:
Installing a virtual Microsoft KM-TEST Loopback Adapter provides a permanently active virtual network interface that never reports a disconnected link.
Assigning a static IP (e.g., 192.168.1.100) allows Simatic Shell and WinCC services to communicate smoothly offline.
Controller Emulation via S7-PLCSIM:
S7-PLCSIM emulates the S7-400 / CPU 410 controller in PC memory.
WinCC communicates with PLCSIM using internal memory-mapped IPC drivers or Named Connections routed through the virtual terminal bus.

Step-by-Step Implementation Procedure

Configuring Standalone PCS 7 OS Simulation:

Install Microsoft KM-TEST Loopback Adapter (if no active NIC):
- Open Windows Device Manager (devmgmt.msc).
- Select 'Network adapters' -> Action -> 'Add legacy hardware'.
- Select 'Install hardware that I manually select from a list' -> Network adapters -> Manufacturer: Microsoft -> 'Microsoft KM-TEST Loopback Adapter'.
- In Windows Network Connections, configure the loopback adapter with static IP 192.168.1.100 and subnet 255.255.255.0.
Configure Simatic Shell:
- Open Windows File Explorer -> expand 'This PC' -> right-click 'Simatic Shell' -> select 'Settings...'.
- Under 'Network Adapter', select the Microsoft KM-TEST Loopback Adapter (or active Wi-Fi/Ethernet adapter).
- In PCS 7 V9.0+, configure 'Encrypted communication': if prompted, assign an encryption migration key or disable encryption for local testing.
- Click OK to restart Simatic Shell services.
Launch S7-PLCSIM and Download Controller Logic:
- Open SIMATIC Manager -> click the S7-PLCSIM icon on the toolbar.
- In PLCSIM, select the target interface (e.g., PLCSIM(ISO) or PLCSIM(Named Connections)).
- In SIMATIC Manager, select the AS program -> PLC -> Download to download the CFC chart logic into PLCSIM.
- Set PLCSIM to RUN-P.
Configure WinCC Project for Local Runtime:
- Open WinCC Explorer on the OS project.
- In WinCC Tag Management -> expand 'Named Connections' -> right-click connection -> System Parameters -> verify connection links to PLCSIM.
- Click the 'Activate' icon in WinCC Explorer to launch Runtime.
Verify Local Operation:
- Confirm graphics displays show live values from PLCSIM.
- Toggle simulated inputs in PLCSIM and verify that WinCC faceplates update dynamically.

Verification

To verify the offline simulation setup:
1. Open Windows File Explorer -> Simatic Shell; verify that the local PC station appears without error badges.
2. In WinCC Explorer, verify that the project computer name matches the local PC's Windows Computer Name (or adjust via WinCC Project Properties).
3. In WinCC Runtime, open Channel Diagnosis (WinCCChannelDiagnosis.exe); verify that the Named Connection state displays 'OK' with green checkmarks.
4. Test an operator control: open an APL motor faceplate, click Start, and observe feedback updating in PLCSIM.

Limitations and Operational Precautions

Operational precautions:
- Never connect a laptop running standalone simulation with loopback or active PLCSIM instances directly to a live plant bus; doing so can cause IP and MAC conflicts with production servers.
- When reconnecting the laptop to the plant, remember to re-open Simatic Shell Settings and switch the network binding back to the physical plant bus network card.
- S7-PLCSIM cannot accurately simulate high-speed hardware interrupts, PROFIBUS master token ring rotations, or certain specialized CP communication functions.

Engineer FAQ

Can I run a PCS 7 OS project without a physical PLC?

Yes, by configuring S7-PLCSIM to simulate the automation station and binding Simatic Shell to a local network adapter or loopback interface.

Why does Simatic Shell fail when my laptop is not connected to a network?

Because physical network cards report 'cable disconnected', preventing Windows network sockets from initializing. Installing a Loopback Adapter resolves this.

How do I change the bound network card in Simatic Shell?

In Windows Explorer, right-click 'Simatic Shell' -> select 'Settings...' -> choose the desired network adapter.

Do I need to change the WinCC Computer Name for local simulation?

Yes, the WinCC project properties computer name must match the local laptop's Windows computer name to activate runtime locally.

Can PLCSIM simulate redundant S7-400H controller switchovers?

Standard S7-PLCSIM simulates a single CPU instance; PLCSIM Advanced or multiple PLCSIM instances are required for complex dual-controller simulations.