基于嵌入式Linux串口专用交换机的设计

发布时间：2019-03-31 18:49

【摘要】：本设计基于汽车检测线系统的通信模块而产生，解决了传统的RS-232C串行通信在连接多个设备时必需在PC机上加多串口卡，且要实现数目众多的智能仪器设备与远端主机之间的通信，串行通信在长距离传输时数据的传输速率及数据可靠性将大大下降，并且基于RS-232C的串行通信组网将会变得非常复杂。本文开发了一个基于ARM9和Linux操作系统的嵌入式串口专用交换机设备，该设备可以使现有的智能仪器拥有联网功能，实现了数据的长距离传输、远程数据的采集与控制等功能。本系统能够接收来自8路串行端口的数据并进行数据的存储、处理、转换使之成为可在网络中传输的以太网数据包；同样也可以接收来自以太网的数据包并进行数据的解包、分析、格式的转换与判断，然后发往指定的串行端口。实现了串行终端数据与TCP/IP网络数据的双向透明传输。本文研究内容包括： 1.分析了嵌入式串口专用交换机设计需实现的目标，制定了详细的系统设计方案。选用了三星公司的S3C2440A作为微处理器及嵌入式Linux系统作为本设计操作系统。 2.硬件电路设计。首先描述了硬件设计的总体方案，然后将系统硬件划分为处理器模块电路设计、以太网接口模块电路设计、串口扩展模块电路设计、通信隔离模块电路设计四大部分，详细阐述了设计过程。 3.嵌入式系统的构建。包括Uboot移植、Linux操作系统的移植、根文件系统的制作及设备驱动程序的开发、着重的介绍了设备驱动程序的开发。最终构建完成了嵌入式串口专用交换机专用平台，为应用程序的运行与调试提供了必要的环境。 4.软件的设计。在Linux平台下利用多线程网络程序设计，设计了嵌入式串口专用交换机服务器端程序。并在Windows平台利用Socket网络编程设计了客户端的API函数，可方便用户进行二次开发。
[Abstract]:This design is based on the communication module of automobile detection line system, which solves the problem that the traditional RS-232C serial communication must add multiple serial cards to PC when connecting multiple devices. And in order to realize the communication between a large number of intelligent instruments and remote hosts, the data transmission rate and data reliability of serial communication in long-distance transmission will be greatly reduced. And the serial communication network based on RS-232C will become very complicated. In this paper, an embedded serial port special exchange device based on ARM9 and Linux operating system is developed. The device can make the existing intelligent instrument have the function of networking, realize the long-distance data transmission, remote data acquisition and control and so on. The system can receive the data from 8 serial ports, store and process the data, and transform it into Ethernet data packet which can be transmitted in the network. Data packets from Ethernet can also be received and unpacked, analyzed, converted and judged, and then sent to a specified serial port. The two-way transparent transmission of serial terminal data and TCP/IP network data is realized. The research contents of this paper include: 1. The target of the design of embedded serial port special purpose exchange is analyzed, and the detailed system design scheme is worked out. The S3C2440A of Samsung Company is chosen as microprocessor and embedded Linux system as the operating system of this design. 2. Hardware circuit design. Firstly, the overall scheme of hardware design is described. Then the system hardware is divided into four parts: processor module circuit design, Ethernet interface module circuit design, serial port expansion module circuit design and communication isolation module circuit design. The design process is described in detail. 3. The construction of embedded system. Including Uboot porting, Linux operating system transplantation, root file system making and device driver development, the development of device driver is emphatically introduced. Finally, the special platform of the embedded serial port exchange is constructed, which provides the necessary environment for the running and debugging of the application program. 4. Software design. Using multi-thread network program design under Linux platform, the server-side program of embedded serial port special exchange is designed. In the Windows platform, the API function of the client side is designed by using Socket network programming, which is convenient for the user to carry on the second development.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TN915.05;TP368.1

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