Upgrade of the Control System for the LHC High Level RF

The acceleration of particles in CERN’s Large Hadron Collider (LHC) is carried out by sixteen superconducting radiofrequency (RF) cavities. Their remote control is taken care of by a complex system which involves heterogeneous equipment and interfaces with a number of different subsystems, such as high voltage power converters, cryogenics, vacuum and access control interlocks. In view of the renovations of the CERN control system planned for the Long Shutdown 2 (LS2), the control software for the RF system recently underwent a complete bottom-up refactoring, in order to dispose of obsolete software and ensure the operation of the system in the long term. The upgraded software has been deployed one year before LS2, and allowed successful operation of the machine. This paper describes the strategy followed in order to commission the system and to guarantee LHC nominal operation after LS2.