The distributed control and data system in HT-7 tokamak

A control and data processing system for HT-7, the first super-conducting tokamak in China, is developed in order to both control the experimental system and process the huge amount of experimental data (600 MB/shot). A fully distributed structure is adopted. The distributed control system (DCS) includes several subsystems, such as those for the main control, synchronization, safety, interlock, data acquisition and data analysis, physical data management, remote control facility via networks, etc. The basic element of the DCS is the personal computer (PC) with a Fiber Distributed Data Interface based on a fast network. The system uses multiple data-transfer paths in parallel and categorizes the entire computer functions into the servers. The subsystems for main control, communication, and data management are described in details.