Virtual controllers and devices are a perfect example of the IT/OT convergence which plays a decisive role for PROFINET in automation technology. With the technical advancements being made in virtualization technology and the growing demand for virtual controllers and devices, PROFIBUS & PROFINET International (PI) has adapted the PROFINET certification process accordingly and reached an important milestone with the PROFINET Test Bundle V2.45.0 released in August of 2024.
Virtual controller and device instances can be officially tested and certified effective immediately. PROFIsafe can also be used in a virtual context as already confirmed by TÜV Süd with a letter of conformance.
Easy scale up
Virtualized PROFINET devices offer the user a number of advantages, for example with regard to flexibility and scalability, high performance and easy integration. Thus, virtualized PROFINET devices run on standard hardware and in virtualized environments, which enables easy scaling and adaptation to different requirements. This reduces the need for special hardware and decreases the overall costs for companies.
Thanks to seamless integration into existing IT infrastructure, virtual controllers boast high performance and reliability. They use TCP/IP and IT standards to ensure stable and efficient communication between the devices on a network. Through corresponding resource management, multiple controller and device instances can be operated at the same time on a single piece of hardware.
These freedoms also come along with challenges with regard to guaranteeing the expected quality and reliability of PROFINET devices. Important aspects here include:
- Runtime and communication behavior can be significantly influenced by the virtual environment and transport network.
- The transport network considerably affects the jitter of PROFINET communication.
- Virtualization and the transport network are not fully under the control of the virtual instance provider.
To ensure the expected high level of quality in the form of interoperability and availability despite this variance, the certification approach for virtual PROFINET instances was divided into two steps: In the first step, the PROFINET test laboratory conducts a test based on a simple example configuration of the virtual PROFINET instance. The optionally implemented and obligatory functions are tested based on the corresponding conformance class here. Following successful completion, a certificate listing the reference hardware used at the test laboratory, the virtualization technology and the guaranteed resources can be applied for.
In the second step, implementation of the specific instance is tested on the actual physical system. For this purpose, a tool is being developed which must be used on site by the customer to test the performance of the transport network and the requirements regarding the time behavior (latency and jitter, among other things) and the network load.
Virtualization technology will continue to develop and come along with new requirements to be included in the specifications and certification tests. PI will continue to competently accompany this process.
