The upgrade of data processing and storage system for EAST NBI

Abstract

Inspired by the ITER organization's CODAC system, the current experimental system architecture is being progressively redesigned using the experimental physics and industrial control system (EPICS) to meet the needs of future long pulse experiments. As part of the overall experimental system, the data processing and storage system (DPSS) is mainly used to provide services of data processing and data storage for the experimental system. However, with the data processing mechanism of the previous DPSS, the previous experimental system is unsatisfactory in terms of real-time experimental data feedback, and the data processing mechanism of the previous DPSS is not compatible with the new architecture. Given that the original DPSS no longer fits the current experimental characteristics in terms of both functionality and demand so that it is necessary to redesign and upgrade the original DPSS to adapt to the new architecture. In view of the soft real-time and distributed characteristics of EPICS, the upgraded DPSS will be redesigned based on the data processing mechanism of EPICS. And it uses an adaptive strategy that allows the experimental system to automatically match more appropriate data uploading modes according to the rate of data acquisition. For this purpose, a data transmission protocol based on the TCP/IP protocol has been proposed. With regard to software optimization, the upgraded DPSS uses technologies of double-buffer and MMAP to optimize data exchanging between memory spaces. In terms of data storage, the upgraded DPSS adopts the segment strategy to manage experimental data efficiently. In addition, to prevent problems caused by abnormal circumstances, a guarantee mechanism for data storage is provided in the upgraded DPSS. After being tested, the upgraded DPSS will later be integrated into the general control system of EAST NBI.