Upgrades to the Slow Control of the IDMAR Junction Box

IDMAR is an underwater, multidisciplinary research infrastructure currently under construction in the abyssal depths of the Mediterranean Sea, off the southeastern coast of Sicily. It integrates innovative sensors for real-time studies in the submarine environment. One of IDMAR’s primary use cases is ARCA, the Cherenkov detector being developed by the KM3NeT Collaboration as partof the KM3 Neutrino Telescope, designed to study cosmic neutrinos at TeV-PeV energies. A key component of IDMAR is the Junction Box (JB)[2], which receives electro-optical signals transmitted from onshore via the Main Electro-Optical Cable and distributes them to underwater user experiments, such as the KM3NeT[1] Detection Units (DU). The original JB design has been upgraded to support a greater number of detection units, optimizing costs in the process. Version 2 of the JB integrates two independent sub-units within the same mechanical enclosure, each featuring its own electro-optical connection. Despite their independence, a unified management approach has been maintained to align with operational practices. Another major advancement in the slow control system is the enhancement of authentication and authorization mechanisms. In addition to local authentication based on usernames and passwords, external authentication providers are now supported. Furthermore, fine-grained user and group permission management has been implemented to improve access control. This paper outlines the key decisions behind this significant architectural evolution and their implementation.