Tool-neutral virtual commissioning means building the plant model, the signal interface and the test cases once, independent of any PLC vendor, then connecting each controller through its own emulator. A Siemens filler tested with S7-PLCSIM Advanced and a Rockwell palletiser tested with FactoryTalk Logix Echo can then run against the same line model and the same test script.
For UK machine builders and plants that buy equipment from several OEMs, that is closer to reality than a single-vendor suite. This article explains the building blocks, a step-by-step method and the trade-offs.
Why tool-neutral virtual commissioning matters in the UK
UK food, drink and packaging lines are rarely single-brand. A bottling line might combine a Siemens-controlled filler, a Rockwell-controlled case packer and a CODESYS-based labeller, each from a different supplier. Machine builders face the mirror image: the same machine sold to one customer who specifies Siemens and another who specifies Allen-Bradley.
Much of the virtual commissioning material online is written by a vendor about its own toolchain. That is useful for single-vendor machines, but it leaves the integrator with a mixed line to stitch together, and test results that cannot be compared across controllers.
The building blocks
| Layer | Examples | Keep it neutral by |
|---|---|---|
| Controller emulation | S7-PLCSIM Advanced, FactoryTalk Logix Echo, CODESYS or TwinCAT soft PLCs | Using each vendor's own emulator for its own code |
| Plant model | Emulate3D, Siemens NX MCD or Process Simulate, an iUNI twin | Building one model of the line, not one per controller |
| Coupling | OPC UA, vendor simulation APIs, FMI | Defining one signal list that every coupling maps to |
| Test cases | Written from the FDS | Writing tests in plain language, not in a tool's scripting format |
Siemens describes S7-PLCSIM Advanced as simulating SIMATIC S7 controllers without physical hardware so programs can be tested and debugged against digital twins. Rockwell calls Logix Echo its next-generation controller emulator, and positions Emulate3D for virtual commissioning and operator training. Each is good at its own platform; the neutral part is how you organise the work around them.
Tool-neutral virtual commissioning, step by step
- Write the test cases from the FDS first. Start, stop, faults, recipe changes, handshakes between machines. Plain language, with expected results and timings.
- Freeze one signal list for the whole line. Every signal between machines and between controller and model, with data type, units, scaling and direction. This is the contract every tool maps to.
- Build the plant model once. Model the line at the fidelity the tests need: conveyors, sensors, actuators and product flow, not cosmetic detail.
- Connect each controller through its own emulator. PLCSIM Advanced for the Siemens machine, Logix Echo for the Rockwell machine, a soft PLC for the CODESYS machine.
- Couple through standard interfaces where you can. OPC UA is the common choice between emulators and models. Where a model built in one simulation tool must be reused in another, the Functional Mock-up Interface packages it in a standard format.
- Run the same script against every controller. Machine-to-machine handshakes are where mixed lines fail, so test them across vendors, not machine by machine.
- Record results against the test case IDs, so the evidence reads the same whichever controller was tested and can be attached to the FAT.
Trade-offs to understand before you start
Timing. OPC UA coupling is convenient but not deterministic at millisecond level. It is fine for conveyors, valves and sequences; fast motion, registration and servo synchronisation usually need the vendor's own tightly coupled simulation. Emulator limits. Emulators do not always reproduce I/O module diagnostics, safety behaviour or communication timing exactly, so read each vendor's restrictions before claiming a test is complete. Licences. Each emulator and modelling tool has its own licence; a neutral approach does not remove those costs, it stops you paying for the same model twice.
Model ownership. Decide early who owns the plant model after handover. If the machine builder keeps it, the end user cannot re-test a change three years later. If the end user owns it, they need the licences and skills to run it. A neutral signal list and plain-language test cases make either choice workable, because the model can be rebuilt in another tool from the same contract if it has to be.
When is a single-vendor suite simpler? When the machine is one brand end to end, motion-heavy and built by one team. Then a Siemens or Rockwell toolchain from model to controller is usually the shortest path, and we would say so.
Redefine what is possible with Emulate3D and FactoryTalk Echo
Rockwell Automation
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Watch on YouTubeHow Wartens approaches it
Our engineers program in TIA Portal, Studio 5000, TwinCAT and CODESYS. Through iUNI, the group's digital twin company, we build the line model from your CAD at 1:1 scale so one model can serve commissioning, operations and training. See our digital twins and virtual commissioning service. For the people side of the job, read about virtual commissioning rehearsal, and for the basics, our original guide to virtual commissioning in the UK.
Next step
Send us the line layout, the controller list and the FDS for each machine through our contact page. We will propose a model, a signal list and a test plan, with a written scope and price.
