The integration of custom radiation tolerant electronics in industrial control systems

In the CERN accelerator complex, the conventional magnets are protected against overheating and power converter failures by a PLC-based system, the so-called Warm magnet Interlock Controller (WIC). In 2026, the systems installed in the LHC-SPS transfer lines will reach end-of-life after 20 years of successful operation. Furthermore, Siemens' announcement regarding the phase-out of the S7-300 series necessitates development of a second-generation magnet protection system. Initially, a solution based on the existing purely industrial configuration was considered, involving a simple upgrade of the PLC modules to the new Siemens S7-1500 series. However, due to the susceptibility of this new series to radiation-induced electronic effects, this approach was deemed unfeasible. As a result, a new control system architecture was explored, integrating both an industrial control processor and custom in-house designed radiation-tolerant electronics. To maintain overall system integrity and ensure seamless interfacing with the existing SCADA layer, it was decided to retain the industrial CPU – Siemens S7-1516 PLC – as the process control master. For the slave units, operating in radiation-prone environments, a CERN-developed platform, Distributed I/O Tier, was chosen. The new system is presently being installed in the beam transfer lines. The technical challenges and chosen solutions are described in this paper.