设备检测数据传输系统的研究与开发

发布时间：2018-02-03 06:44

本文关键词： 数据传输 XML-RPC Modbus协议 XML Socket Python3.3　出处：《东北大学》2014年硕士论文　论文类型：学位论文

【摘要】：设备检测作为工业控制中的重要部分,需要进行主控的上位机和进行数据采集的下位机共同完成。设备检测提供表示各类设备运行状态的数据,对于安全生产意义重大。在设备检测过程中,数据传输是必不可少的环节,传统的数据传输受限于下位机,在扩展、移植或更新方面有很大的局限性。本文研究的数据传输系统,使用功能强大、价格低廉的树莓派微型计算机作为下位机,利用其性能上的优势,编写扩展性良好、移植性强的通信程序,突破传统传输系统的局限。本文通过研究XML-RPC和Modbus协议的特性,找到它们与数据传输的结合点,并以此结合点为核心逐步构造出设备检测数据传输系统。论文介绍了研究背景以及相关技术,然后分析当前亟需解决的问题,即打破“专门机器专门软件”的局限,创建一套可以在多种平台和多种网络下进行通信的数据传输软件。本文研究的数据传输系统以树莓派微型计算机为基础,在上面布置服务器程序,使其作为下位机进行数据采集并与上位机进行通信。服务器提供XML-RPC和Modbus两种服务使得数据传输在两个层面上独立。XML-RPC服务部分利用HTTP协议报文封装XML格式的数据,只要在服务器端注册好方法,则可以在不同操作系统的客户端与服务器端之间直接进行方法的调用,使数据传输系统实现了在操作系统层面的独立。Modbus服务部分提供基于TCP的Modbus协议的实现,利用Modbus协议中定义的数据模型来存取数据,这样,其它实现Modbus协议的传输网络就可以与本系统进行通信,实现了在异构网络层面的独立。在数据的存储方面,服务器端采用将数据存储到XML文件中的方式,在使用时提取即可,利用XML技术可以方便对数据进行整理和验证。在优化系统性能方面,本文提出了备份线路和数据中转站的概念。备份线路以“备份环”的形式连接下位机,将下位机中的数据循环备份,在有线路故障的情况下,保证上、下位机的通信正常。数据中转站在线路备份的基础上进行修改,使得上位机可以利用一台下位机返回多个下位机的数据,提高传输效率。
[Abstract]:As an important part of industrial control, equipment detection needs the host computer of main control and the lower computer to collect data. Equipment detection provides data indicating the running state of all kinds of equipment. In the process of equipment detection, data transmission is an essential link, the traditional data transmission is limited by the lower computer, in the expansion. The data transmission system studied in this paper uses the powerful and inexpensive raspberry pie microcomputer as the lower computer, and takes advantage of its performance advantages. This paper studies the characteristics of XML-RPC and Modbus protocols, and finds out the combination point between them and data transmission in order to break through the limitation of traditional transmission system by writing communication programs with good expansibility and strong portability. The paper introduces the research background and related technology, and then analyzes the problems that need to be solved. Namely break the limitation of "special machine specialized software", create a set of data transmission software that can communicate under many kinds of platforms and networks. The data transmission system studied in this paper is based on raspberry microcomputer. Set up a server program on top. The server provides XML-RPC and Modbus services to enable data transmission to be independent of .XML-RPC services at both levels. Part of the HTTP protocol packet encapsulates the data in XML format. As long as the method is registered on the server side, the method can be called directly between the client and server side of different operating system. The data transmission system realizes the implementation of Modbus protocol based on TCP in the independent. Modbus service part of the operating system. The data model defined in the Modbus protocol is used to access the data so that other transmission networks that implement the Modbus protocol can communicate with the system. In the aspect of data storage, the server adopts the way of storing data into XML file, and can extract the data when using. The data can be sorted and verified conveniently by using XML technology. In the aspect of optimizing the system performance, this paper puts forward the concepts of backup line and data transfer station. The backup line is connected to the lower computer in the form of "backup loop". In the case of line failure, the communication of the lower computer is normal and the data transfer station is modified on the basis of line backup. So that the upper computer can use one lower computer to return the data of more than one lower computer, so as to improve the transmission efficiency.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN919.6

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