Virtual controllers and devices are a good example of IT/OT convergence and play an important role for PROFINET in automation technology. With the technological advances in virtualization technologies and the growing demand for virtual controllers and virtual devices, PROFIBUS & PROFINET International (PI) adapted the PROFINET certification process accordingly and reached an important milestone with the release of PROFINET Test Bundle V2.45.0 in August 2024. Virtual controllers and device instances can now be officially tested and certified. PROFIsafe can also be used in a virtual context, as TÜV Süd has already confirmed with its Certificate of Conformity.
Virtualized PROFINET devices offer users many benefits, including flexibility and scalability, high performance and ease of integration. Virtualized PROFINET devices therefore run on standard hardware and in a virtualized environment, making them easier to scale and adapt to different requirements. This reduces the need for specialized hardware and lowers the overall costs for companies.
Thanks to their seamless integration into existing IT infrastructure, virtual controllers are characterized by high performance and reliability. They use TCP/IP and IT standards to ensure stable and efficient communication between devices in the network. Through proper resource management, multiple controller and device instances can operate simultaneously on a single piece of hardware. However, these freedoms also come with challenges in terms of ensuring the expected quality and reliability of PROFINET devices. Important aspects are:
- Runtime and communication behavior can be heavily influenced by the virtual environment and the transport network.
- The transport network has a significant impact on the jitter of PROFINET communication.
- Virtualization and the transport network are not under the full control of the virtual instance provider.
To ensure the expected high level of quality in the form of interoperability and availability despite these differences, the certification approach for virtual PROFINET instances was split into two steps. In the first step, the PROFINET test lab performs simple tests. Example configuration of a virtual PROFINET instance. Optionally implemented and mandatory features are tested based on the corresponding conformance class. After successful completion, you can request a certificate listing the reference hardware, virtualization technologies and guaranteed resources used in the test lab.
In the second step, the implementation of a specific instance is tested on a real physical system. For this purpose, tools have been developed that are required to test the performance and time behavior requirements of the transport network (including delay and jitter), as well as the network load at the customer’s site.