Virtual Commissioning Software: Open Source & AI-ready
Test your PLC code against the simulated machine before the hardware exists – with a tool whose source code you can read.
What virtual commissioning software does
In virtual commissioning, the real controller – PLC or robot controller – is commissioned against a simulated machine model. Drives, sensors and material flow behave like the real plant; the automation code runs unchanged. Errors in sequence logic, interlocks and signals surface while they can still be fixed at the desk – not on site.
In the digital twin lifecycle this is the second of four stages: the sales and concept simulation becomes the virtual commissioning model, later the integration test with MES, and finally the 3D HMI on the running machine. One model, built once, reused across all stages.
Traditional vs. virtual commissioning
In traditional commissioning, the control code meets the mechanics for the first time at the real machine – errors surface on site, under schedule pressure. With virtual commissioning this happens weeks earlier: on the digital twin, with no downtime and no risk to the hardware.
| Traditional | Virtual | |
|---|---|---|
| Errors in PLC code | only surface at the real machine | are found on the model – before assembly |
| Test coverage | only what the hardware allows | any scenario, including faults and edge cases |
| On-site commissioning | full scope including software debugging | up to 75% shorter |
| Risk | crashes and mechanical damage possible | risk-free on the digital twin |
The 75 percent is not a marketing number: in the TU Munich field study (Zäh/Wünsch), virtual commissioning cut real commissioning time by 75 percent – and the share of control functions that were right the first time rose from 37 to 84 percent.
In practice: SEW-EURODRIVE
"Unity’s open ecosystem makes virtual commissioning scalable. High-fidelity visualization, CAD integration, and real-time physics, helps us create realistic digital twins to optimize automation, enabling faster, safer, more efficient commissioning."
Made in Germany – and verifiably open
realvirtual is developed in Germany, with more than 18 years of automation experience. But an origin label is not an argument – verifiability is: realvirtual Professional ships with full C# source code, the handover format is open GLB, and the delivery viewer is AGPL-licensed on GitHub. Don’t trust the label. Read the code.
For the EU Machinery Regulation 2027 this means: we answer the obligation to keep digital documentation available over the machine’s lifetime with architecture instead of a contract – open formats and an open-source viewer cannot be taken away from you.
AI-ready instead of AI promises
The free, open-source MCP server integrates AI agents like Claude or Cursor directly into the engineering workflow: 150+ tools that let the AI create components, wire signals and move drives. The twin’s knowledge is passed to the LLM in structured form – and because the source code is open, the AI understands the framework from the very code you read.
The AI backend is yours to choose: EU-hosted or fully local. The result: a fully wired virtual commissioning model in record time instead of days, straight from the CAD model.
Deep dive: Virtual Commissioning AI – AI agents and vision AI in the digital twin →
Runs on your machine – not in the cloud
The simulation runs locally on the engineering PC. There is no GPU farm, no data center, no streaming infrastructure and no forced cloud – your machine data and CAD models never leave your company.
Deployment is royalty-free as standalone applications for Windows, Linux, macOS and more. In addition, documentation and machine models reach your customers as GLB in the browser – free, no installation, no account.
SiL or HiL? The terms in short
Virtual commissioning runs in different configurations – the difference is where the control code executes.
Software-in-the-Loop (SiL)
The controller runs as a software simulation – such as Siemens PLCSim Advanced or TwinCAT on the same PC. No hardware needed, scales freely, ideal for early testing. realvirtual connects directly to PLCSim Advanced, SIMIT and TwinCAT.
Hardware-in-the-Loop (HiL)
The real PLC hardware is connected to the simulated machine model over the network – e.g. an S7-1500 via S7-TCP or a Beckhoff IPC via ADS. The controller’s real timing is part of the test; typical cycle times of 10–50 ms are sufficient for smooth motion.
Model-in-the-Loop (MiL)
Control and behavior models from MATLAB/Simulink couple directly to the twin via FMI – for drive and process models before the first line of PLC code exists.
Your controller is supported
25+ industrial interfaces share one signal architecture: wired once, freely interchangeable – from Siemens S7 and PLCSim Advanced through Beckhoff TwinCAT, OPC UA, MQTT and EtherNet/IP to robot controllers and FMI/Simulink.
Transparent pricing
realvirtual Professional, per concurrent developer – no runtime fees for delivered applications. Getting started is free: realvirtual Starter with the Siemens S7 interface on the Unity Asset Store.
Requires a valid Unity license (not included).
Frequently asked questions about virtual commissioning
What does virtual commissioning software cost?
realvirtual Starter is free (including the Siemens S7 interface). realvirtual Professional costs €1,250 net, one-time per developer – with no runtime fees for delivered applications. All prices are published on the website.
Which controllers are supported?
25+ interfaces: Siemens S7 and PLCSim Advanced, Beckhoff TwinCAT, OPC UA, MQTT, Modbus, EtherNet/IP, Bosch ctrlX, Keba, plus robot controllers from KUKA, Fanuc, ABB, Universal Robots and more – and FMI/Simulink for external behavior models.
What is the difference between SiL and HiL?
With Software-in-the-Loop (SiL) the controller runs as a simulation (e.g. PLCSim Advanced) on the PC; with Hardware-in-the-Loop (HiL) the real PLC is connected over the network. realvirtual supports both with the same signals – from early SiL testing to the HiL acceptance test.
Can I read the source code?
Yes. realvirtual Professional ships with full C# source code; the realvirtual WEB browser viewer is open source (AGPL) on GitHub. The GLB handover format is openly documented.
Do I need a cloud or special hardware?
No. The simulation runs locally on a standard engineering PC. No GPU farm, no data center and no cloud connection is required; your data stays in-house.
How does virtual commissioning relate to the digital twin?
Virtual commissioning is the second of four digital twin stages: concept simulation, virtual commissioning with the real controller, integration testing with MES, and the 3D HMI on the running machine – the same model is reused across all stages.
See it running
Open the live demo in your browser — no installation, no account. Or start free: realvirtual WEB is open source on GitHub.