【作者】 徐灵伟；

【导师】 刘飞；

【作者基本信息】 江南大学 ， 控制理论与控制工程， 2007， 硕士

【摘要】 随着互联网的普及,嵌入式系统已越来越重视网络特性,基于嵌入式Internet网络将会成为下一代工业控制网络的重要选择,并将带来工业控制新的革命。然而,目前大多数嵌入式系统还处于单独应用的阶段,工业测控领域也只是利用孤立于Internet以外的控制通信网络,如RS485,CAN,I2C等现场总线实现MCU组网,由工控机汇总和管理所有现场采集的数据信息,最后实现与外界远端客户机的通信。如果能将这些小型的嵌入式控制设备具有连接到Internet上,就可以方便低廉地将信息传送到远端客户机上从而可以实时高效地进行远程监控。但是,在工业测控系统中将这些嵌入式设备接入Internet的困难在于,工业控制网络中广泛存在8位和16位的嵌入式控制设备,而在这些以低端微处理器为核心的每一个嵌入式设备上移植TCP/IP协议栈是不切实际的。针对上述问题一种较好的解决方案是,构建一个以32位为核心的嵌入式瘦服务器,取代以PC胖服务器为主的传统网络接入方案,通过RS232、RS485和CAN总线轻量级网等方式,将多个嵌入式设备连接在一起,一方面担当TCP/IP和轻量级网之间有关协议的转换任务,另一方面为远程浏览器提供数据访问,数据传输等服务。基于以上设想,本课题利用32位ARM7核S3C4510B所提供的丰富的系统资源和强大的处理能力,通过移植运行在源码公开的实时嵌入式操作系统精简内核uC/OS-II上的一套精简的TCP/IP协议栈LWIP,提出一种应用在烟气连续排放监测系统(Continuous Emission Monitoring System,简称CEMS)的网络接入方案,将广泛应用在工业控制网络中的现场总线所采集到的数据通过Internet传送到远程监控设备。为了实现上述目标,笔者主要做了以下工作:1.编写针对S3C4510B的启动代码,初始化必要的硬件设备,创建精简内核uC/OS-II需要的一些信息,完成中断向量映射,时钟设置,内存参数设置和堆栈初始化等任务,从而将系统的软硬件环境带到一个合适的状态;2.围绕中断的处理在S3C4510B上移植uC/OS-II作了三种不同的尝试,即嵌套式中断形式,非嵌套式中断形式和软中断系统调用形式,最后总结了移植中存在的问题并提出了改进的方法;3.根据精简内核uC/OS-II的特点,完成LWIP协议栈操作系统模拟层的封装,将LWIP移植到uC/OS-II平台上,实现TCP/IP协议栈的最基本功能;4.针对烟气连续排放监测系统(CEMS)现行网络接入方案存在的一些不足,为了产品的预研和日后的升级,将以上构建的嵌入式瘦服务器应用于CEMS中,提出一种可行的嵌入式Internet接入改进方案。更多还原

【Abstract】 With the popular of the Internet, embedded system emphasizes networking features.The technology of the embedded internet will lead the industrial networking into the new era, making it a great revolution in the industrial world.However, the remote monitoring system always utilizes 8-bit and 16-bit MCUs which are widely used in industry to shoulder the task of gathering the data through traditional light weight netwoking Field Bus such as RS485/RS232、CAN etc. With inherent shortcomings, no uniform standards seriously limited the merits we pursuit. Making it worse, it is impossible and unnecessary to plant TCP/IP stack onto every low level MCU. To solve this problem,a feasible solution would be to construct a 32-bit Embedded System,not only playing a role as a gateway to connect FieldBus with Internet, but also realizing a‘Lean Server’to offer services for remote clients.And this paper introdues a solution to realize a‘Lean Server’on a 32-bit S3C4510B,a powerful ARM7 MCU. It immigrates the downsized TCP/IP stack LWIP into uC/OS-II, a customized RTOS planted into the S3C4510B previously, finally realizing most applications with embedded Internet. At the end of this paper, it introduces how to utilize this embedded system in the CEMS,making it possible to reconstruct the original networking solution to monitor the data gathered by low-level embedded devices through Internet which is connected by FieldBus widely used in industrial networking.To achieve these goals, the major contribution of this paper are as follows:1. Tailoring the bootloader for S3C4510B, completing such tasks as initializing hardware devices which necessary, configuring memory parameters, initializing stack pointers.2. Focusing on approaches of handlering interrupts, this paper makes three attemps to plant uC/OS-II onto ARM7 core S3C4510B, one for non-nesting Interrupt, the second for nesting Interrupt, the last for System Call using Software Interrupt, finally proposing solution to promote original shortcomings existing in planting.3. After analyzing the Operating System Simulating Layer of LWIP, It immigrates the downsized TCP/IP stack LWIP into uC/OS-II to realize the basic function of TCP/IP;4. It finally offers a feasible solution to utilizes this embedded system implemented above to reconstruct original networking of Continuous Emission Monitoring System(CEMS), making FieldBus integrated into Internet.更多还原