The Research Of EAST Real-time Network Communication System

With the gradual upgrading of EAST device and the continuous increase of the discharge time,the plasma control requirements of EAST PCS have become more and more complex and more and more data are required for real-time feedback control.As a large scale nuclear fusion experiment device,the EAST device has a complex structure,contains many subsystems distributed in different electromagnetic environments,and the sampling frequencies and the number of acquisition channels of subsystems are nothe same.It's difficult for PCS to complete acquisition of measurement data produced by subsystems during the control cycle(100us).However,the quality of the measurement data is closely related to the control effect and even directly affects the performance of the plasma.Therefore,it is necessary to select a suitable real-time communication system to transmit the data collected by each subsystem during the experiment to the PCS in real time,and at the same time ensure that the data can be reliably transmitted to the EAST data server.In order to meet the above requirements,this paper designed the EAST real-time network communication system,which can ensure that the experimental data of each subsystem is completely stored on the basis of the EAST data server;at the same time,the data is real-time and without distortion in the PCS control period(100us).Transfer to PCS for complex control calculations.The system efficiently uses the original data acquisition system of each subsystem to reduce the burden of PCS collection.This thesis investigates the real-time network communication system used in domestic and international tokamak devices,and analyzes the requirements and feasibility of EAST real-time network communication systems according to the current situation of EAST;it adopts a reflective memory(RFM)card characterized by high speed,good real-time performance,and high reliability,the MRG-R(Real Time and Grid-RealTime)operating system provides deterministic response time,and multi-threading technology with high concurrency;then it describes the hardware architecture and software structure,finally realizes the EAST real-time network communication system.The system has good scalability and flexibility and can adapt to EAST's dynamic demands.In order to ensure the stable and reliable operation of the EAST discharge experiment,this thesis also designs the EAST network monitoring system based on Cacti to realize the flow monitoring of the experimental network equipment and the alarm function of the faulty equipment.The innovations of this thesis are summarized as follows:(1)In the EAST real-time network communication system,a distributed real-time framework of "multi-type networks" was designed,and RFM real-time networks and Gigabit Ethernet were respectively deployed.The RFM network is responsible for real-time transmission of the data collected by each subsystem to EAST PCS within the control period of 100us,realizing the real-time sharing of measurement data among subsystems;Ethernet is responsible for transmitting the above data synchronously and reliably to EAST data server.RFM's digital transmission mode solves the problems of electromagnetic interference and signal loss during the long-distance transmission of measurement data from the EAST device site to the PCS,which improves the quality of the measurement data and provides a better control effect for the PCS.(2)The real-time performance of the EAST real-time network communication system is improved by using MRG-R real-time operating system,and combining with the CPU affinity,multi-core binding technology,real-time scheduling strategy and priority strategy,and multi-thread concurrent technology to achieve the real-time transmission of data from the subsystems to PCS within 100 ?s.(3)This thesis conducts in-depth research on the data read and write modes of RFM,solves the problem about slow read and write speeds of the RFM with the PCIE interface,and optimizes the read/write speed from the original 8.6MBps/47,7MBps to the current 51.4MBps/51.3MBps(when reading and writing 512 Bytes),which significantly reduces the real-time transmission delay of data.(4)The development of the EAST network monitoring system based on Cacti enabled effective monitoring of the 7*24H of the EAST experimental network.