LXI网络仪器后台处理的设计与实现

发布时间：2018-03-26 22:25

本文选题：LXI　切入点：HISLIP　出处：《西安邮电大学》2017年硕士论文

【摘要】：LXI(LAN eXtension for Instrumentation)技术是局域网在仪器领域的扩展,由此构建的仪器测控平台具有成本低、可重构性强以及仪器组件可以分布式部署等优点,LXI已经成为仪器总线的发展方向。LXI总线相较于传统仪器总线有很大优势,它不受带宽和底板结构因素的限制,随着以太网吞吐量的逐步提升,能够满足不同条件下自动化测试系统的要求。为了突破传统VXI总线测控系统中仪器组件不能实现不同区域内分布式部署的限制以及构造模块化精简的仪器测控系统平台,本文对LXI网络仪器进行了研究,并对LXI网络仪器后台处理部分的功能需求进行设计实现。LXI网络仪器后台出台处理部分的设计实现分为仪器组件自动发现模块、SNMP(Simple Network Management Protocol)客户端、HISLIP(High-Speed LAN Instrument Protocol)客户端和后台处理服务总调度四个模块,所有模块均在linux平台下开发。仪器组件自动发现功能采用DHCP(Dynamic Host Configuration Protocol)协议和HISLIP协议相结合的方式进行设计,能够自动感知并记录接入测控网络中的仪器组件;SNMP客户端完成测控主机对各仪器组件的控制和管理,在设计中嵌入AES_128_CBC对称加密算法,解决SNMPv2协议数据在网络中传输安全性较低的问题;HISLIP客户端按照LXI总线的标准规定设计实现,用于完成测控后台与仪器组件之间测控指令和测量数据的传输工作;后台处理服务总调度模块作为外部应用程序调用后台处理服务的统一接口程序,用户只需获取接口模块的具体参数形式即可调用后台处理提供的所有服务,总调度模块设计中多任务处理采用进程形式实现,主进程和其它服务进程之间的通信和信息共享通过共享内存这种高效的IPC方式设计完成。本文首先对LXI仪器总线和网络仪器进行了分析,研究LXI总线的标准规范和特点优势以及网络仪器的系统架构,深入分析HISILIP协议的通信规程和交互模式,进而设计实现HISLIP协议客户端;其次分析研究DHCP服务器的工作原理和日志文件,结合 HISLIP 协议和 SCPI(Standard Commands for Programmable Instruments)设计实现仪器组件自动发现功能模块。另外,在研究SNMPv2和AES_128_CBC对称加密算法的基础上,将二者相融合实现了具有数据加解密功能的SNMP客户端;再者通过分析HISLIP客户端、SNMP客户端和仪器组件自动发现模块的接口参数,设计实现调用后台处理服务的统一接口程序,外部应用程序只需获取统一接口模块的具体参数形式即可调用相关服务。最后,针对本文实现的后台处理功能模块,结合实验室资源搭建LXI网络仪器测控系统并对所有模块进行功能测试,结果表明各功能模块均能满足预期设计要求。
[Abstract]:LXI(LAN eXtension for Instrumentation is an extension of local area network in instrument field. The instrument measurement and control platform based on this technology has low cost. LXI has become the developing direction of instrument bus. LXI bus has a great advantage over traditional instrument bus, and it is not limited by bandwidth and bottom plate structure factors. With the increase of Ethernet throughput, It can meet the requirements of automatic test system under different conditions. In order to break through the limitation that the instrument components in traditional VXI bus measurement and control system can not realize distributed deployment in different areas and construct a modular and concise instrument measurement and control system platform. In this paper, LXI network instruments are studied. The function requirement of LXI network instrument background processing part is designed and implemented. The design and implementation of the backstage processing part of LXI network instrument are divided into two parts: the automatic discovery module of instrument components, the simple Network Management protocol client side and the client side of HISLIPP High-Speed LAN Instrument Protocol. Four modules of total dispatch of station processing service, All modules are developed on linux platform. The automatic discovery function of instrument components is designed by the combination of DHCP(Dynamic Host Configuration protocol and HISLIP protocol. It can automatically perceive and record the control and management of each instrument component by the instrument component AES_128_CBC client, and embed the AES_128_CBC symmetric encryption algorithm in the design. In order to solve the problem of low security transmission of SNMPv2 protocol data in the network, HISLIP client is designed and implemented according to the standard of LXI bus, which is used to complete the transmission of measurement and control instructions and measurement data between measurement and control background and instrument components. The master scheduling module of background processing service is a unified interface program for external application program to invoke background processing service. The user only needs to obtain the specific parameters of the interface module to call all the services provided by background processing. In the design of the total scheduling module, the multi-task processing is realized in the form of process. The communication and information sharing between the main process and other service processes is accomplished through the design of the efficient IPC mode of shared memory. Firstly, this paper analyzes the LXI instrument bus and network instrument. The standard specification and characteristic advantage of LXI bus and the system architecture of network instrument are studied. The communication protocol and interaction mode of HISILIP protocol are deeply analyzed, and then the client of HISLIP protocol is designed and implemented. Secondly, the working principle and log files of DHCP server are analyzed, and the automatic discovery function module of instrument components is designed and implemented by combining HISLIP protocol with SCPI(Standard Commands for Programmable Instruments.In addition, based on the research of SNMPv2 and AES_128_CBC symmetric encryption algorithms, The SNMP client which has the function of data encryption and decryption is realized by the fusion of the two. Furthermore, by analyzing the interface parameters of the HISLIP client and the instrument module, the unified interface program of calling the background processing service is designed. The external application only needs to obtain the specific parameter form of the unified interface module to invoke the related services. Finally, for the background processing function module implemented in this paper, Combined with laboratory resources, the LXI network instrument measurement and control system is built and all modules are tested. The results show that each functional module can meet the expected design requirements.
【学位授予单位】：西安邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP311.52;TP393.1

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