Configuring SIMIT Virtual Controller for Virtual Commissioning of SIMATIC PCS 7 Systems

SIMATIC SIMIT Virtual Controller (VC) fully supports virtual commissioning of legacy and modern PCS 7 automation systems, including PCS 7 V7.1, V8.x, and V9.x. The SIMIT Virtual Controller emulates the firmware, execution timing, and communication protocols of S7-400 and S7-410 controllers without physical hardware. To configure a PCS 7 V7.1 test environment, export the hardware configuration and symbol tables from STEP 7, import them into SIMIT VC, and establish virtual plant bus communication over softnet interfaces.

Architecture of SIMIT Virtual Controller vs. Physical Hardware and S7-PLCSIM

In comprehensive process plant validation, virtual commissioning enables engineers to verify automation programs, safety matrices, alarm configurations, and operator graphics before equipment delivery. In SIMATIC PCS 7 environments, simulation was historically performed using S7-PLCSIM. However, S7-PLCSIM exhibits severe architectural limitations:
* It cannot simulate redundant fault-tolerant controllers (S7-400H).
* It executes as a single-instance desktop task with asynchronous, non-deterministic execution times.
* It cannot simulate distributed fieldbuses (PROFIBUS-DP / PROFINET) or multiple synchronized controllers communicating peer-to-peer.

SIMIT Virtual Controller (VC) resolves these limitations by executing high-fidelity controller emulation:
1. Direct Firmware Emulation: Emulates S7-400 (e.g., CPU 417-4H MLFB 6ES7417-4HT14-0AB0 or CPU 410-5H MLFB 6ES7410-5HX08-0AB0) firmware, instruction sets, system function blocks, and memory management.
2. Multi-Controller Coordination: Multiple Virtual Controllers run concurrently on a single PC or distributed simulation cluster, communicating over virtual subnets.
3. Deterministic Time Scaling: Supports real-time execution, fast-forward (time compression for long chemical batches), and freeze/step execution for detailed fault injection.

Virtual Controller and Simulation Compatibility Matrix

Review version compatibility and capabilities across SIMIT simulation interfaces:

Simulation PlatformSupported PCS 7 VersionsController Redundancy (H-System)Max Simulated ControllersTime Scaling (Freeze / Fast-Forward)S7-PLCSIM Classic (V5.4)PCS 7 V6.x to V9.xNo (Single CPU only; no H-mode)1 CPU instanceLimited (Pause/Run only)SIMIT VC V3.0 (Legacy)PCS 7 V7.0, V7.1Yes (Redundant H-CPU support)Up to 8 Virtual ControllersYesSIMIT VC V8.0 / V8.1PCS 7 V7.1 SP3, V8.0, V8.1Yes (Full S7-400H emulation)Up to 32 Virtual ControllersYes (0.1x to 100x real-time)SIMIT VC V9.x / V10.xPCS 7 V8.1, V8.2, V9.0, V9.1Yes (S7-400H and CPU 410-5H)Up to 32 Virtual ControllersYes (Full snapshot / rewind)

Licensing and hardware notice: SIMIT Virtual Controller requires dedicated SIMIT VC software licenses per emulated controller instance. Check procurement options with authorized Siemens distributors.

Configuring SIMIT Virtual Controller for PCS 7 V7.1 and V8 Systems

Follow this verified workflow to set up a virtual commissioning environment for PCS 7 V7.1:

Verify Software Version Compatibility:
* Open the Siemens Compatibility Tool for Automation and Drive Technology (http://www.siemens.com/kompatool).
* Confirm that your installed SIMIT version (e.g., SIMIT V8.1 or V9.0) supports the STEP 7 / PCS 7 project export formats. SIMIT V8.x can directly import PCS 7 V7.1 hardware and symbol tables.
Export Configuration from PCS 7 Engineering Station:
* In SIMATIC Manager (PCS 7 V7.1), open the project.
* Open HW Config for each AS controller.
* Select Station > Export to generate the hardware configuration file (.cfg).
* Export the symbol tables (.asc or .sdf) and CFC chart reference data.
Configure Virtual Controller Coupling in SIMIT:
* In SIMIT, create a new simulation project.
* In the navigation tree, right-click Couplings and select New Coupling > Virtual Controller.
* Run the VC Configuration Wizard:
- Import the .cfg hardware file exported from STEP 7.
- Select the CPU model (e.g., S7-417-4H).
- Assign the simulated MAC and IP addresses matching the original project.
Compile and Download Program to Virtual Controller:
* Launch the SIMIT Virtual Controller instance.
* On the PCS 7 Engineering Station, open Set PG/PC Interface.
* Change the access point S7ONLINE to the virtual network adapter (e.g., SIMIT Virtual Network Adapter or Softnet PN).
* In SIMATIC Manager, select the AS station and execute PLC > Download. The project downloads into SIMIT VC exactly like a physical hardware controller.

Synchronizing Communication Across Virtual Controllers and OS Clients

To connect the PCS 7 Operator Station (WinCC) to the SIMIT Virtual Controller:
1. Ensure the WinCC OS project's Named Connections or ISO-on-TCP connection properties point to the IP address assigned to the SIMIT VC.
2. In WinCC Explorer, open Tag Management, right-click the SIMATIC S7 Protocol Suite channel, and verify that connection status indicates healthy cyclic handshakes.
3. Start SIMIT simulation: Process values generated by the simulation model (transmitters, limit switches) feed directly into controller I/O addresses, which SIMIT VC processes and delivers to WinCC faceplates in real time.

Verification

Verify virtual commissioning readiness:
1. In SIMIT, click Start Simulation: The Virtual Controller indicator transitions to solid green (RUN).
2. On the Engineering Station, open a CFC chart and switch to Test > Watch On: Confirm live execution of blocks without communication errors.
3. In WinCC Runtime, operate an actuator faceplate: Confirm that commanding a motor start in WinCC energizes the output in CFC, triggers the feedback model in SIMIT, and illuminates the running icon on the OS screen.

Limitations and Operational Precautions

SIMIT Virtual Controller runs on standard Windows operating systems; while deterministic relative to the simulation clock, it does not guarantee hard hardware real-time synchronization below 10 ms across large distributed models.
Highly specialized hardware modules (such as FM 350 counter modules or third-party serial CP cards) cannot execute proprietary on-board coprocessor code inside SIMIT VC; their behavior must be modeled using SIMIT simulation components.
Ensure CPU core affinity is properly distributed in SIMIT settings on multi-core PCs to prevent high simulation workloads from starving the WinCC OS runtime process.

Engineer FAQ

Can SIMIT VC simulate an S7-400H redundant controller pair?

Yes. SIMIT VC fully emulates fault-tolerant S7-400H controller pairs. You can simulate master-standby failover, fiber-optic link failure, and single-CPU maintenance modes.

Do I need to change my CFC charts or block addresses to run on SIMIT VC?

No. SIMIT Virtual Controller uses the exact same compiled machine code, addresses, and symbol tables as the physical controller. No modifications to CFC charts are required.

Can SIMIT VC be run on a separate computer from the PCS 7 Engineering Station?

Yes. SIMIT can reside on a dedicated high-performance simulation workstation connected to the ES and OS stations over a standard local Ethernet network.