Author: Piglowski, D.A.
Paper Title Page
MOPKS021 High-speed Data Handling Using Reflective Memory Thread for Tokamak Plasma Control 203
  • S.Y. Park, S.H. Hahn, W.C. Kim
    NFRI, Daejon, Republic of Korea
  • R.D. Johnson, B.G. Penaflor, D.A. Piglowski, M.L. Walker
    GA, San Diego, California, USA
  The KSTAR plasma control system (PCS) is defined as a system consisting of electronic devices and control software that identifies and diagnoses various plasma parameters, calculates appropriate control signals to each actuator to keep the plasma sustained in the KSTAR operation regime. Based on the DIII-D PCS, the KSTAR PCS consists of a single box of multiprocess Linux system which can run up to 8 processes, and both digital and analog data acquisition methods are adapted for fast real-time data acquisition up to 20 kHz. The digital interface uses a well-known shared memory technology, the reflective memory (RFM), which can support data transmission up to 2Gbits/s. An RFM technology is adopted for interfacing the actuators, 11 PF power supplies and 1 IVC power supply, and the data acquisition system for plasma diagnostics. To handle the fast control of the RFM data transfer, the communication using the RFM with the actuators and diagnostics system is implemented as thread. The RFM thread sends commands like target current or voltage which is calculated by the PCS to the actuators area of RFM for plasma control and receives measured data by the magnet power supply. The RFM thread also provides the method for monitoring signal in real time by sharing data of diagnostics system. The RFM thread complete all data transfer within 50us so that data process can be completed within the fastest control cycle time of the PCS. This paper will describe the design, implementations, performances of RFM thread and applications to the tokamak plasma controls utilizing the technique.  
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