Virtual commissioning (VIBN) has become standard practice in many mechanical engineering projects today. Especially when developing PLC programs, errors can be detected much earlier, allowing for optimal preparation for physical commissioning. But how realistically can machines actually be tested virtually today?
From logic testing to motion analysis
The answer depends heavily on the simulation’s objective. Sometimes it is sufficient to test PLC logic against simulated inputs and outputs. Interlocks, mode changes, or sequence controls can thus be validated virtually at an early stage, long before the actual hardware is available.
But as soon as motion and processes come into play, 3D models become essential. The PLC is tested using the machine’s digital twin. The integrated sensors respond to virtual movements, axes move to specific positions, and material flows are simulated. This allows typical problems such as faulty sequences, collisions, or timing conflicts to be identified early on.
Especially for complex systems, robotics, or highly automated production lines, this enables software development and mechanical design to proceed in parallel.
Where VIBN reaches its limits
Despite all its advantages, virtual commissioning does not completely replace the physical machine. Physical effects such as wear and tear, electrical interference, or real-world tolerances can currently only be simulated to a limited extent.
Therefore, what matters is not maximum model complexity, but rather the appropriate level of detail for the specific development task.
In practice, it is also evident that the success of virtual PLC tests depends on consistent engineering data. Only when mechanics, electrical engineering, and control logic are optimally integrated can a functional digital twin be created.
Modern simulation platforms such as iPhysics therefore go far beyond mere 3D visualization. The platform integrates mechanical models, control logic, and simulation behavior within a single engineering environment. This creates a digital twin capable of simulating real-world processes in a traceable manner.
PLC programs can thus be tested under realistic conditions as early as the initial development phases, long before the actual system is built. Movements, sensor states, material flows, and processes are dynamically represented within the simulation. At the same time, different disciplines can work in parallel, as mechanical, electrical, and software development teams work on the same model.
This significantly reduces the amount of fine-tuning required, especially for complex machines and automated systems. Errors are identified earlier, allowing them to be avoided on the actual machine.
Conclusion
Today, testing PLC programs virtually is not only possible in many fields but also makes good business sense. Especially for complex machines and automated systems, this approach allows errors to be detected early, development times to be shortened, and commissioning to be significantly accelerated. The key question here is not whether virtual commissioning can truly replace everything, but rather which problems can be solved before the actual machine is built. Virtual PLC testing is thus increasingly becoming a central component of modern VIBN strategies. It should not be viewed as an isolated simulation tool, but rather as an integral part of networked engineering.
