For a steady state operation of JT-60SA, a plasma feedback control using various diagnostic sensor signals plays an essential role. To realize this, Real-Time Diagnostic Signals acquisition System, RTDS, which utilizes PC-based real-time OS “INtime”, has been under consideration toward JT-60SA project.

Real-Time Processor, RTP in JT-60 data processing system, which utilized a WS-based computer with real-time UNIX, was becoming increasingly difficult to maintain, manage, and improve due to the aging of the system and the limited capability of the CPU.

To solve these problems and assess the feasibility of introducing clustered architecture, a prototype had been developed with the existing RTP and a VxWorks computer at hand. Its effectiveness as the architecture of the next RTDS was verified on JT-60U experiments, but the actual RTDS will employ PC-based “INtime” system, which consist of a general-purpose personal computer and a real-time operating system “INtime”.

Moreover, long-pulse experiments of more than 400s will be planned in JT-60SA project. Therefore, real time monitoring will be required as an essential function that displays acquired diagnostic signals in real-time during long-pulse experiment. This function will also be realized by utilizing the RTDS.