【作者】 张学锋；

【导师】 廖常初；

【作者基本信息】 重庆大学 ， 电气工程， 2003， 硕士

【摘要】 与其它现场总线相比，由于以太网技术具有开放性、结构简单、带宽易于扩展、兼容性能好和成本低廉等优点，近年来在工业控制的高层已得到了广泛的应用。而把以太网技术用于工业控制的底层网络，却还没有得到充分的研究。利用以太网技术作为现场总线，用于工业控制的底层网络，既有利于现场总线的发展，又能有效地提高现场总线的传输速率和简化现场总线的种类。本论文首先简单介绍了当前现场总线的发展情况，在分析和比较各种现场总线技术的基础上，指出了其存在的问题，在参照国内外关于用以太网技术作为现场总线研究的基础上，提出了在以太网协议的应用层对现场传输的信息进行规范的方法。该方法能提供报文服务和短帧信息结构，满足现场通信的实时性要求。接下来为了实现这个方法，论文介绍了利用W78LE516B单片机和RTL8019AS网卡驱动芯片开发的RS-232C转以太网通信协议的嵌入式以太网通信模块，利用该模块可实现将现场设备的RS-232C通信转换为以太网通信，也可以直接将该模块嵌入单片机控制设备使用。然后，论文对嵌入式以太网通信模块的硬件电路设计和驱动程序编写作了详细的介绍，并在不改变以太网TCP/IP协议主体结构的基础上，对TCP/IP协议作了精简处理，以满足现场通信的实时性和可靠性要求。最后论文分析了嵌入式TCP/IP协议的总体框架设计、帧的封装过程及数据包的发送和接收流程。在完成论文撰写的过程中，本课题完成了对嵌入式以太网通信模块的设计，实现了RS-232C通信协议和以太网通信协议的相互转换功能，并在利用C语言模块化的编程思想的基础上，用单片机实现了嵌入式TCP/IP协议的设计，该设计具有很强的实时性和移植性。调试结果表明该嵌入式以太网通信模块具有集成度高、可靠性高和成本低等特点，可应用于远程设备的实时监控和访问更多还原

【Abstract】 Compared with other fieldbus technology, Ethernet technology provides the advantages of being open, simple structure, low cost, easily extended frequency, and good compatibility. Herein, in recent years, Ethernet technology has been extensively applied in the upper industrial control. However, up to date, there is not so much report on the application of Ethernet technology in the bottom networks of industrial control as the fieldbus. Though the application in this respect can remarkably promote the development of fieldbus, greatly improve the transmitting speed and simplify the types of used fieldbus.This dissertation firstly introduces the latest development in fieldbus, and after comparing and analyzing the today’s several main fieldbus technology in depth, it points out the existent problems in these fieldbus technology. Referring to the up to date research on the application of Ethernet to the fieldbus, it proposes a solution to standardize the transmitted information in the field on the application level of Ethernet. According to this solution, the requirement of real-time in field communication can be fulfilled as a result of its message service and short frame structure. To complete this idea, this dissertation reports the design for an embedded Ethernet module for data exchange between RS-232C and Ethernet communication with a micro-controller W78LE516B and a network card driver chip RTL8019AS. This Ethernet module can be directly used to convert the RS-232C information mode to Ethernet information mode or be embedded in the equipments controlled by microprocessors. Afterwards, this dissertation introduces the designing of hardware circuit and compiling of corresponding driving program in detail. This design simplified the TCP/IP without changing its main structure to meet the demand for real-time and reliability in field communication. In the end of this dissertation, the general frame for embedded TCP/IP, process of frame packing, and the procedure in sending and receiving data are comprehensively analyzed.In this project, an embedded Ethernet module was designed and the data exchange between RS-232C protocol and Ethernet protocol was fulfilled with this module. At the same time, based on the modular programming method provided by C language, an embedded TCP/IP was realized with MCU. This embedded TCP/IP has highly real-time and can be transplanted easily. After debugging, it turns out that the designed embedded Ethernet module is of the particularities of high integration, high reliability and low cost<WP=6>and can be used to supervise and access the remote equipment in real time更多还原