What Is Virtual Commissioning? Testing the PLC First
Control software meets the machines for the first time at commissioning, and that is usually where the errors show up. Virtual commissioning moves that meeting onto a computer, before the site.
Commissioning a line is the moment the control software meets the real machines for the first time. A wrongly mapped sensor, two steps in the wrong order or a missing interlock usually turn up right there. Each one is found on site, fixed on site, and delays the line’s start of production.
Virtual commissioning moves that meeting onto a computer, before the site: the PLC program and the robot programs are connected to a 3D simulation of the line and tested.
What is virtual commissioning?
The simulation model of the line, with its conveyors, sensors, drives and robots, is connected to the PLC. The PLC controls the model instead of the real machines, and the model sends the sensor signals back: when a part passes a light barrier, the PLC sees it as it would on the real line.
The control software therefore runs in a realistic setting while the line does not exist yet. If the error is in the software, the model shows it before a machine on site does.
How it works
- The line is modelled. Layout, machines, conveyors and robots are built in 3D. If a factory simulation was done for the investment decision, its model can carry on from here.
- The PLC is connected. In Visual Components, the connection runs over OPC UA, or directly for Siemens S7 PLCs. A physical PLC or a simulated one can be used.
- Signals are mapped. The PLC’s inputs and outputs are linked one by one to the sensors, drives and robots in the model.
- Scenarios are run. Start-up, normal production, faults and exceptions are tried in the model. Errors found are fixed in the software, and the scenario runs again.
- The site starts with tested software. Commissioning on site begins with control software that has already run against the model.
What it finds
- Sequence and interlock errors: a step starting early, two movements cleared at the same time.
- Wrongly mapped signals: address errors in the I/O list, sensors wired the wrong way round.
- Robot programs against the cell: whether the signal the robot waits for is the one the PLC sends. Programs prepared with offline robot programming are tried in the same model.
- Cycle time under the real control logic: cycle and capacity with the program that will run the line, not with assumed rules.
- Fault and exception behaviour: what the line does when a sensor fails, a station blocks or the emergency stop is pressed.
Some of these situations are expensive or risky to try on a real line. In the model they can be repeated as often as needed.
Simulation, virtual commissioning and the digital twin
The three terms get mixed up, but they answer three different questions about the same line:
| Its question | What runs the line | When | |
|---|---|---|---|
| Factory simulation | How much will the line produce, where is the bottleneck? | Assumed rules | Before the investment decision |
| Virtual commissioning | Does the control software work? | The real PLC program | Before commissioning on site |
| Digital twin | What is happening on the line right now? | The real line | Once the line is running |
That is usually the order, too: simulation checks the investment, virtual commissioning checks the control software, and a digital twin follows the running line. We covered the difference between simulation and a digital twin in a separate post.
What it needs
- Simulation software: in Visual Components, PLC connectivity is part of the Premium package.
- The PLC program: a PLC with an OPC UA server, or a Siemens S7; physical or simulated.
- The line’s details: layout, equipment list and the I/O list.
- Time from the automation team: the team that writes the PLC program is the one that maps the signals and fixes the errors in the software.
How we support it
Ono Teknoloji is the authorised Visual Components distributor for Turkey and the Middle East. For virtual commissioning we provide the Visual Components Premium licence, training in Turkish and start-up support. While the line is modelled and the PLC connected, we work alongside your automation team or your integrator. We can also build the line’s simulation model ourselves as part of factory simulation and engineering consultancy.
The details are on the virtual commissioning page. If you would like to talk about a new line or cell, write to us.
Frequently Asked Questions
What is virtual commissioning?
It is testing PLC and robot programs against a 3D simulation of the line before the line is built. The PLC controls the model instead of the machines, and the model sends the sensor signals back; errors in the control software are found in the model rather than on site.
What is the difference between virtual commissioning and factory simulation?
Factory simulation shows how much a line will produce and where the bottleneck is, using assumed rules. In virtual commissioning the real PLC program runs the line, and the question is whether the control software works. The same 3D model can serve both.
Which PLCs can be used for virtual commissioning?
Visual Components connects to PLCs over OPC UA, and has a direct connection for Siemens S7 PLCs. A simulated PLC can be used instead of a physical one. PLC connectivity is part of the Visual Components Premium package.
Which software can be used for virtual commissioning in Turkey?
One of them is Visual Components. Ono Teknoloji is the authorised Visual Components distributor for Turkey and the Middle East, and provides the licence, training in Turkish and project support for virtual commissioning.