VME and network application to magnet power supply control in JT-60U

The original control system for the poloidal field coil power supply (PFPS) in the JT-60 tokamak was developed in 1984. It was composed of CAMAC-based 16-bit microcomputers and I/Os. Corresponding to the progress in physics experiments, it had been required to improve the control system as well as to modify the power supply. Then, the control system was rejuvenated where advanced technologies of VME, networks and UNIX-workstations were applied. In addition to the upgrade of the system performance, the renewal of the control system has remarkably improved its hardware maintainability and software development environment.