Development of real-time network translator between ITER synchronous data bus network and reflective memory

Abstract

To achieve the real-time controllability of plasma, real-time network is required in fusion experiments. The KSTAR plasma control system (PCS) adopts reflective memory (RFM) as a real-time network because RFM-based network has low latency and low jitter. However, KSTAR also adopted synchronous data bus network (SDN) to provide real-time network to a fueling system. The performance of SDN is comparable to RFM, and SDN can be implemented in an existing 10-GbE (Gigabit Ethernet) network. SDN is an ITER real-time network based on a UDP multicast over a 10-GbE cut-through packet-switching infrastructure. To establish the connectivity between these real-time networks, we develop a translator between RFM and SDN. The translator reads data from RFM, makes a predefined SDN packet, and sends the packet to its destination in real time. Moreover, the translator receives the SDN packet and writes the data to the predefined data address in real time. This translator translates each data in accordance to the KSTAR timing system. Therefore, each data synchronizes with the KSTAR timing system. Moreover, the translator also defines the monitoring functionality of SDN and RFM using EPICS (Experimental Physics and Industrial Control System). This paper presents the algorithm of the translator system and the experimental setup. The translator was tested on MRG-R kernel 3.10. This experiment shows the real-time performance of the translator.