基于以太网的智能传输接口研究是为了把RS232串口通信和RS485/422总线通信统一到以太网中，即完成串口-网络协议转换。由于RS232和RS485/422的传输距离有很大的局限性，而且串口的数据传输速率大小受条件的限制，因此，需要一个串口-网络协议转换器实现串口数据向网络数据的转换，从而提高数据传输的稳定性。它可以使主机从繁重的事务中解脱出来，只需要完成以太网通信即可，这样就增加了数据宽度，使其能更好的为计算机监控系统服务。 本文设计了一个嵌入式串口-网络智能传输接口，它主要完成串口模块和以太网模块之间的协议转换，以及串口和以太网之间数据的存储控制与转换。同时，它可以对多种类型的数据进行处理，一方面，接收来自串口设备的数据流，并对其进行格式转换，使之成为可以在以太网中传播的数据帧；另一方面，也可以将以太网中的数据帧转换成串行数据送达相应的串口设备，即完成了RS232，RS485/422和以太网之间的双向转换。 对该接口的设计主要分为硬件和软件两个方面。硬件部分将μC/OS-Ⅱ作为嵌入式操作系统，选择LPC2210作为控制器，串口处理模块采用MAX3232芯片对UART进行RS232电平转换，以太网控制芯片选用常用的10M ISA总线接口的RTL8019AS。为了满足通信过程中的数据缓存和一定的系统运行空间的需求，片外扩展了512K字节的SRAM，2M的片外FLASH用来存放代码。在硬件中分别对控制部分，电源部分，网络传输部分，串口传输转换部分做了详细的分析与说明，软件部分中通过对串口及串口通信理论的研究，给出了系统启动代码实现，编写了串口驱动、网卡驱动程序，实现了μC/OS-Ⅱ操作系统的移植，对TCP/IP协议栈的主要工作过程及部分实现代码进行了论述，最后对μC/OS-Ⅱ操作系统移植结果和系统功能进行了测试。

Research of intelligent transmission interface based on ethernet unifies RS232 and RS485/422 bus communication to internet, that is, the purpose of the research is a UART-network protocol converting interface.Because of the limitation of transmission distance and serial transmission rate we need a UART-network protocol converting interface to convert serial data to internet data in order to improve the data transmission stability. Once doing these the host machine could free itself from heavy business, and the only thing it need to do is internet communication, so it can increase data width, service for computer monitoring systerm better. The paper designs a embedded UART-network protocol converting interface. It is mainly engaged in protocol conversion between UART modules and internet modules. It mainly completes the control and the convertion of data storage between UART communication and internet. It can process a variety of data, and receive UART data stream form UART devices, then convert the data format that could transmit in internet. While the data frames come from internet will be analyzed, and then sended to UART devices coverted to UART data. The paper can be devided into two parts, which are hardware design and software design. Hardware selectsμC/OS-Ⅱ as embedded operating system, LPC2210 as controller, and UART processing module uses MAX3232 to convert RS232 electric for UART. Internet contronl chip selects RTL8019AS using common 10M ISA bus interface. In order to meet data cache for communication and a certain room for system operating, the system extends 512K bytes SRAM and 2M FLASH for storing codes outside of chip. Hardware parts introduce control parts, power parts, internet transmission parts, UART transmission conversion detailedly. Software parts give a introduce of UART and UART communication, and the startup code implementation of system, driver of UART, transplant of μC/OS-Ⅱ operating system, main process and part codes of TCP/IP protocol stack, then give a test of transplant of μC/OS-Ⅱ and function of system at last.