Data Acquisition System of Neutral Beam Injector on EAST

In order to supervise the elements of the neutral beam injector (NBI) spatially located at several places, a distributed NBI data acquisition system (NBIDAS) on experimental advanced superconducting tokamak (EAST) is developed in this paper. NBIDAS consists of field instrument and measurement devices, servers and remote data processing terminals. In order to remotely manage and monitor the field devices of the NBI system, a device management client software is also developed as the human–machine interfaces between the field devices and remote system administrators. A control signal acquisition system is developed for diagnosing these generated analog and digital signals from the NBI control system. NBIDAS based on network technologies is capable of extending system functions and upgrading devices. The detail of the architecture and implementation of the NBIDAS on EAST is discussed in the paper.     

高密度塑料闪烁体探测器的数据获取系统设计

由中国科学院近代物理研究所承担的塑料闪烁体探测器研究项目,其目标是开展空间粒子探测、重构入射电子轨迹、区分电子和光子、鉴别重离子。为配合该探测器测试工作,设计了一套完备的数据获取电路(DAQ)与上位机软件。DAQ接收4块前端电子学(FEE)板的数据,可完成360路电子学通道的数据读出;接收上位机的控制命令并分发给各FEE;接收探测器的击中信息并产生触发信号;接收FEE的遥测数据并传给上位机。该DAQ与上位机通过USB总线和RS232总线实现实时通信。上位机软件基于LabWindows/CVI软件平台开发,实现对FEE电子学系统的控制、数据读取与保存,以及FEE系统运行状态参数信息的实时显示。该数据获取系统电路结构紧凑、功能完善,上位机软件具有良好的人机交互界面。经现场实际运行,DAQ与上位机软件满足设计要求,目前已成功应用于塑料闪烁体探测器读出电子学测试系统。     

Design of Timing System Software on EAST–NBI

Neutral Beam Injector (NBI) is one of the main plasma heating and plasma current driving methods for Experimental Advanced Superconducting Tokomaks. In order to monitor the NBI experiment, control all the power supply, realize data acquisition and network, the control system is designed. As an important part of NBI control system, timing system (TS) provides a unified clock for all subsystems of NBI. TS controls the input/output services of digital signals and analog signals. It sends feedback message to the control server which is the function of alarm and interlock protection. The TS software runs on a Windows system and uses Labview language code while using client/server mode, multithreading and cyclic redundancy check technology. The experimental results have proved that TS provides a stability and reliability clock to the subsystems of NBI and contributed to the safety of the whole NBI system.     

Development of a Data Acquisition Control System for the First NBI on EAST

Neutral beam injection （NBI） heating is one of the most efficient auxiliary plasma heating methods for fusion devices. The data acquisition control system （DACS） with PXI （pe- ripheral component interconnect extensions for instrumentation） data acquisition card for the first NBI system in the experimental advanced superconducting tokamak （EAST） is presented in this paper. As an important sub-system, DACS is designed to obtain physical measurement signals in the EAST NBI system and to deal and store these data with the Lempel-Ziv-Oberhumer （LZO） lossless data compression algorithm, as well as offer convenient data call-back and access inter- faces to the user for examining and analyzing the data. Experimental results show that accurate data will ensure that researchers correctly analyze it and then properly adjust the experimental parameters or operation, so DACS should take a large step in improving experimental efficiency. Tile hardware and software sections are briefly presented in this paper, and now this system has been tested to be able to work reliably and steadily.     

Design and Application of Experimental Configuration Query Software for EAST NBI

To verify the rationality of experimental configurations before each experiment discharge of Experimental Advanced Superconducting Tokamak (EAST) Neutral Beam Injection (NBI) and to query the experimental configurations under historical shot numbers, an experimental configuration query terminal is needed during NBI experiments. In this paper, the experimental configuration query software is presented which is realized with multithreading technology, TCP protocol, Mysql database and so on. Multithreading technology achieves that different service requests can be dealt by different threads for improving the processing efficiency of the program. TCP protocol ensures reliable network communication between the server and the client. The configurations set by experimental operators are saved to Mysql database of the server with different data tables. The server works under Linux operating system while the client works on Windows operating system. With the help of this application, the current and historical experimental configurations are displayed and queried, thus on the one hand, the current experimental configurations especially the settings of timing sequence and amplitude for NBI each power supply system are verified before each NBI discharge; on the other hand, the typical history configurations can be queried for experimental reproducibility. This application is very practical significance for EAST NBI experiments.     

基于CSS的NBI射频离子源控制程序设计

离子源是中性束注入器(Neutral Beam Injector,NBI)的关键子系统之一,根据射频离子源的实验和运行需求,本文设计了一套基于物理实验与工业控制系统(Experimental Physics and Industrial Control System,EPICS)架构的控制程序,实现对射频离子源实验和调试过程的远程监控功能。NBI射频离子源控制程序通过集成开发平台(Control System Studio,CSS)的交互界面开发模块(Best OPI Yet,BOY)实现友好的人机交互界面,使用Jython实现界面逻辑,支持服务器/客户端和EPICS两种通信架构。程序已经上线近半年,实验表明,射频离子源控制程序具备了放电模式设置、时序幅值设置、设备状态实时监控、采集数据实时波形显示等功能,满足了射频离子源实验的远程控制和数据可视化的需求。     

A new long-pulse data system for EAST experiments

A long pulse discharge requires high throughput data acquisition. As more physics diagnostics with high sampling rate are applied and the pulse length becomes longer, the original EAST (Experimental Advanced Superconducting Tokamak) data system no longer satisfies the requirements of real-time data storage and quick data access. A new system was established to integrate various data acquisition hardware and software for easy expansion and management of the system. Slice storage mechanism in MDSplus is now being used for the continuous and quasi real-time data storage. For every data acquisition thread and process, sufficient network bandwidth is ensured. Moreover, temporal digitized data is cached in computer memory in doubly linked circular lists to avoid the possible data loss by the occasional temporal storage or transfer jam. These data are in turn archived in MDSplus format by using slice storage mechanism called “segments”. For the quick access of the archived data to the users, multiple data servers are used. These data servers are linked using LVS (Linux Virtual server) load balance technology to provide a safe, highly scalable and available data service.     

The EAST distributed data system

In this year, Experimental Advanced Superconducting Tokamak (EAST) has undergone the first tests successfully, and the EAST distributed data system has been reliably operated in the EAST experimental campaigns. This paper gives an overview of this system.The EAST distributed data system is based on the design of, and the experiences with the HT-7 data system; it is aimed to be a distributed, real-time and scalable system. The EAST distributed data system includes control subsystem, data acquisition subsystem and data service subsystem. Control subsystem provides remote control of the all data acquisition units, full information management and state monitoring; data acquisition subsystem that provide real-time and quasi-real-time data support for long-pulse operation consists of a set of autonomous data acquisition units which support autonomous operating and remote control. Data service subsystem is responsible for storing and publishing data.     

Data Server Application Software for Neutral Beam Injection Control System

The neutral beam injection (NBI) heating is one of the mainly auxiliary plasma heating methods for EAST. In this paper, a data server application software is presented for NBI control system. This application software is developed on Centos OS by C programming language with TCP and multithreading technology. It mainly focuses on storing and querying experimental pulse data and engineering data; experimental user’s operation records; experimental configuration information; the collected data after processing; as well as managing and releasing experimental discharge shot number and so on. By using the unified data header structure, the data server software provides universal information exchange interfaces for different service request terminals with different operating platform, such as WinCC, Labview. With the help of data server software, those problems related on the storage, querying and processing of information and data for NBI control system are well solved.     

Design of Waveform Generator for NBI in EAST

The control system of neutral beam injector (NBI) monitors the status of NBI equipments, controls all of the power supply, realizes data acquisition and network, and provides a unified clock for all subsystems of NBI system. As an important part of NBI control system, waveform generator (WG) monitors the parameters of the experiment and displays these parameters in the waveform terminal. The WG software also can send simple experiment commands and make it easy for experiment test. The WG software develops under Windows operating system, using labview language. The design is related to many kinds of technologies, such as client/server communication, multithreading and cyclic redundancy check technology, TCP protocol and so on.     

The web-based user interface for EAST plasma control system

The plasma control system (PCS) plays a vital role at EAST for fusion science experiments. Its software application consists of two main parts: an IDL graphical user interface for setting a large number of plasma parameters to specify each discharge, several programs for performing the real-time feedback control and managing the whole control system. The PCS user interface can be used from any X11 Windows client with privileged access to the PCS computer system. However, remote access to the PCS system via the IDL user interface becomes an extreme inconvenience due to the high network latency to draw or operate the interfaces. In order to realize lower latency for remote access to the PCS system, a web-based system has been developed for EAST recently. The setup data are retrieved from the PCS system and client-side JavaScript draws the interfaces into the user's browser. The user settings are also sent back to the PCS system for controlling discharges. These technologies allow the web-based user interface to be viewed by authorized users with a web browser and have it communicate with PCS server processes directly. It works together with the IDL interface and provides a new way to aid remote participation.     

New developments of the EAST data system

As the discharge time becomes longer, the old EAST data system will not meet the requirements of EAST discharge experiment gradually. The problems mainly focus on continuous data acquisition and real-time data access.To meet the requirements of EAST 1000s discharges, the data acquisition mode, data storage structure and data access interface must be improved or reconstructed. Time slice mechanism is one of the popular solutions for continuous data acquisition and real-time data transfer. Data access of large signal files has been successfully solved via a hierarchical storage management system. Moreover, conventional “remote indexing” is replaced with “local indexing” in data access, which greatly enhanced data access speed. These improvements have been implemented and applied to EAST long-pulse plasma experiments which are described in this paper in detail.     

Development of Data Processing Software for NBI Spectroscopic Analysis System

A set of data processing software is presented in this paper for processing NBI spectroscopic data.For better and more scientific managment and querying these data,they are managed uniformly by the NBI data server.The data processing software offers the functions of uploading beam spectral original and analytic data to the data server manually and automatically,querying and downloading all the NBI data,as well as dealing with local LZO data.The set software is composed of a server program and a client program.The server software is programmed in C/C++under a CentOS development environment.The client software is developed under a VC6.0 platform,which offers convenient operational human interfaces.The network communications between the server and the client are based on TCP.With the help of this set software,the NBI spectroscopic analysis system realizes the unattended automatic operation,and the clear interface also makes it much more convenient to offer beam intensity distribution data and beam power data to operators for operation decision-making.     

The Software Design of a General Purpose Data Acquisition and Control Executive

The software design of an executive which performs general purpose data acquisition, monitoring, and control is presented. The executive runs on a memory-based mini or micro-computer and communicates with a disk-based computer where data analysis and display are done. The executive design stresses reliability and versatility, and has yielded software which can provide control and monitoring for widely different hardware systems. Applications of this software on two major fusion energy experiments at Lawrence Livermore National Laboratory will be described.     

Electrical Parameter Measurement System of the Ion Source for EAST Neutral Beam Injector

Neutral beam injection (NBI) is recognized as one of the most effective means of plasma heating. A virtual instrument (VI) has been designed to provide electrical parameter measurement for the ion source of EAST-NBI. The VI is written using the National Instruments LabVIEW graphical programming language. All data acquisition (DAQ) is accomplished using ADLINK DAQ hardware interface and Task-oriented DAQ Driver. The VI can measure filament voltage, filament current, arc voltage, arc current and accelerating voltage etc. The data obtained from the VI are feedback of the ion source operation state and helpful to direct the operation parameter optimization of the ion source.     

Development of Distributed Control System for Neutral Beam Injector on EAST

A distributed control system of Neutral Beam Injector(NBI) on the Experimental Advanced Superconducting Tokamak(EAST-NBI) is briefly presented in this paper.The control system is developed in accordance with the experimental operational characteristics of the EASTNBI.The NBI control system(NBICS),which is based on the computer network technologies and classified according to the control levels,consists of three levels:a remote monitoring layer,a server control layer,and a field control layer.The 3-layer architecture is capable of extending the system functions and upgrading devices.The timing system provides the reference clock of the synchronization and interlock for the EAST-NBI system.An interlock system ensures the safety of the experiment operators and field devices.Both of the ion sources of the beamline are designed to operate independently.This lays an important foundation for developing a control system for the second beamline on EAST.Experimental results demonstrate that the NBICS meets functional requirements of the EAST-NBI control,and makes experimental operations visual and automatic.     

基于固体探测器SDD的XAFS数据获取系统

X射线吸收精细结构谱学(X-ray Absorption Fine Structure,XAFS)的发展,提出了对低浓度(痕量)元素研究的需求,高灵敏度的固体探测器纷纷被应用到XAFS技术中来。硅漂移探测器(Silicon Drift Detector,SDD)是一种高计数率、高能量分辨率、采用半导体制冷的小型荧光探测器,其商业产品渐趋成熟。北京同步辐射装置1W2B实验站装备了这种小型SDD,并开发了相应采谱软件供用户使用。经过对含Cu 100 mg·L~(-1)浓度的CuSO_4溶液的测试,结果证明这套新的采谱系统可以满足1W2B实验站XAFS实验荧光模式的需求。     

Upgraded data service system for HT-7 Tokamak

A data service system plays an indispensable role in HT-7 Tokamak experiment. Since the former system doesn＇t provide the function of timely data procession and analysis, and all client software are based on Windows, it can＇t fulfill virtual fusion laboratory for remote researchers. Therefore, a new system which is simplified by three kinds of data servers and one data analysis and visualization software tool has been developed. The data servers include a data acquisition server based on file system, an MDSplus server used as the central repository for analysis data, and a web server. Users who prefer the convenience of application that can be run in a Web Browser can easily access the experiment data without knowing X-Windows. In order to adjust instruments to control experiment the operators need to plot data duly as soon as they are gathered. To satisfy their requirement, an upgraded data analysis and visualization software GT-7 is developed. It not only makes 2D data visualization more efficient, but also it can be capable of processing, analyzing and displaying interactive 2D and 3D graph of raw. analyzed data by the format of ASCII, LZO and MDSplus.     

A real-time data transmission method based on Linux for physical experimental readout systems

In a typical physical experimental instrument, such as a fusion or particle physical application, the readout system generally implements an interface between the data acquisition (DAQ) system and the front-end electronics (FEE). The key task of a readout system is to read, pack, and forward the data from the FEE to the back-end data concentration center in real time. To guarantee real-time performance, the VxWorks operating system (OS) is widely used in readout systems. However, VxWorks is not an open-source OS, which gives it has many disadvantages. With the development of multi-core processor and new scheduling algorithm, Linux OS exhibits performance in real-time applications similar to that of VxWorks. It has been successfully used even for some hard real-time systems. Discussions and evaluations of real-time Linux solutions for a possible replacement of VxWorks arise naturally. In this paper, a real-time transmission method based on Linux is introduced. To reduce the number of transfer cycles for large amounts of data, a large block of contiguous memory buffer for DMA transfer is allocated by modifying the Linux Kernel (version 2.6) source code slightly. To increase the throughput for network transmission, the user software is designed into formation of parallelism. To achieve high performance in real-time data transfer from hardware to software, mapping techniques must be used to avoid unnecessary data copying. A simplified readout system is implemented with 4 readout modules in a PXI crate. This system can support up to 48 MB/s data throughput from the front-end hardware to the back-end concentration center through a Gigabit Ethernet connection. There are no restrictions on the use of this method, hardware or software, which means that it can be easily migrated to other interrupt related applications.