Integration of open-source frameworks in industrial plant control systems for large experimental facilities (“Dottorato Industriale” – CRFX)

Modern large-scale experimental facilities, such as ones dedicated to magnetically confined nuclear fusion, often present demanding control requirements, including real-time control, extensive data acquisition and management. Moreover, it is necessary to address the coordination of the many devices involved, which can consistently differ from each other and evolve rapidly due to the ever-changing software and hardware developments. Furthermore, it is not uncommon to have both industrial off-the-shelf devices and custom-built ones working side by side, possibly connected to the same network. Even when involving industrial devices, communication between vendors is sometimes complicated, especially when dealing with legacy hardware. Considering all these issues is paramount when choosing and developing a state-of-the-art Control and Data Acquisition System (CODAS) for the experiment to avoid introducing architecture inefficiencies and difficulties in system maintenance. The three approaches commonly adopted consist of relying on industrial plant control systems (provided by well-known brands, such as Siemens), open-source ones (such as EPICS) or, in some cases, integrating these, which is the choice at ITER with CODAC Core System. However, deciding which strategy is best is complex since each presents advantages and disadvantages. Even when the choice falls on a combined solution, evaluating different factors affecting the final integration level between systems is still necessary. Open-source frameworks often provide great flexibility in customization; in addition, they rarely require a paid licence for their use. On the other hand, they sometimes lack the scalability and robustness granted by commercial industrial systems, which can be expensive in return. This work assesses the optimal integration between industrial systems and open-source frameworks in developing CODAS for a modern nuclear fusion experiment. For this reason, it considers the CODAS of NBTF (the Neutral Beam Test Facility for ITER) and RFX-Mod2 (the largest Reversed Field Pinch experiment in the world) as case studies, conducting an in-depth comparison of their implementations and emphasizing the two approaches' differences, advantages and disadvantages. Since NTBF has to comply with ITER guidelines, its CODAS relies on ITER's CODAC Core System. RFX-mod2, on the contrary, presents more freedom of choice for its CODAC (SIGMA) development but faces challenges related to preexisting hardware and software. Focusing on the revamping strategies of SIGMA for RFX-mod2, this work analyses the architectural, hardware and software novelties introduced to replace obsolete solutions, meet new requirements and ensure a sustainable system for future years.