Open62541 is an open source implementation of the OPC UA communication protocol that is being driven forward by Fraunhofer IOSB together with the Indian system integrator Kalycito and the Open Source Automation Development Lab (OSADL). The software library is written in the C programming language, more precisely in the common subset of C99 and C++98.

Suitable for any hardware

"This means that the software can be used with all common compilers and is so resource-efficient that it can run on any conceivable hardware. It makes it possible to set up dedicated OPC UA servers as well as to integrate OPC UA-based communication into existing applications," explains Dr. Julius Pfrommer, Group Leader Cyberphysical Distributed Systems in the Information Management and Control Technology (ILT) department at Fraunhofer IOSB and lead software architect behind open62541. Bhagath Singh Karunakaran, founder and CEO of Kalycito Infotech Private Ltd. adds: "We firmly believe that the open source development model is ideally suited for basic technologies such as operating systems and communication and leads to better results faster. It avoids unnecessary parallel developments and ensures that innovative software solutions are disseminated quickly."

The certification was carried out using a representative example server based on open62541. The certified scope includes the 'Micro Embedded Device Server' profile, which additionally supports subscriptions, method calls and encryption. Furthermore, open62541 version 1.0 also supports communication according to the OPC UA Publisher/Subscriber model, so that asynchronous communication with multiple participants is also possible. However, no official certification is currently offered by the OPC Foundation for OPC UA Pub/Sub.

The software is licensed under the Mozilla Public License v2.0 (MPL-2.0). This means that the open62541 library may be linked and distributed with proprietary software. Only further developments of the open62541 library itself must be licensed under MPL-2.0 when redistributed.

End-to-end real-time Ethernet solution planned

With this certification, "the project is by no means finished, but the development continues - among other things towards a universal and freely available solution for real-time Ethernet by means of a connection to TSN," says Dr. Carsten Emde, Managing Director of OSADL. Further interested companies are welcome: "The more companies participate in the project, the more powerful and versatile components can be developed and contributed. The project is designed in such a way that companies can join at any time, even after the project has started, and we would therefore like to use this opportunity to motivate other interested companies to participate."