The Design And Implementation Of Remote Supervisory System For Soot-measuration Instruments Based On Embedded Linux

With the development of embedded system, the software design of embedded system depends more and more on the embedded operating system. An excellent embedded operating system can greatly simply the software design, reduce the design period and make the best use of hardware resource of the embedded system. Recent years, Linux is used more and more widely in micro-controller field as an embedded operating system. Compared with other embedded operating systems, embedded Linux has the advantages of its free and open code source, supporting many network protocols, and abundant software resource in the internet.This paper is based on the application research of embedded Linux. In the paper, a remote supervisory system for soot-measuration instruments based on embedded Linux is designed and realized, and the key technologies used in this system are studied.First, two typical designs of the remote supervisory system for soot-measuration instruments are raised, which are based on embedded Linux and industrial Ethernet technologies. After comparing the two designs with each other at performance, cost and application situation, one of them is adopted, which is based on a B/S(Browser/Server) structure using an embedded Linux Web Server.Secondly, the Huaheng embedded Linux development platform is analyzed. It's an embedded Linux development platform based on MC68EZ328 processor and uCIinux operating system. uCIinux is a kind of embedded Linux, which is designed for non-MMU processors. Now, the low-cost processors without MMU is widely used in embedded systems, so research on uCIinux is very practical. In this part, uCIinux is compared with standard Linux at memory-management, process-management and so on, and theapplication programs development method under uClinux is introduced in details.Thirdly, the principle and realization of the whole system is discussed, and the key technologies used is studied such as MODBUS protocol, TCP socket programming, HTTP protocol, single process circle web server and concurrent web server technologies for uClinux, IPC technologies for uClinux and so on. The whole system is made up of 3 modules, they are serial communication module, embedded web server module and the remote operation interface module. Serial communication module which is designed referring to MODBUS realize the communication between host computer (embedded Linux system) and slave devices (soot-measuration instruments). The embedded Linux web server module is the kernel software of the system running as a process. The remote administrators manage the soot-measuration instruments by exchanging data with the embedded Linux web server using a browser. The remote operation interface module provides the remote administrators with a well and convenient operation environment, and it's coded mainly by HTML and VBScript.At last, the real time performance of embedded Linux is studied. The application of Embedded Linux in industrial field is restricted because of its bad real time performance. This paper analyses the key factors which affect the real time performance of embedded Linux, and raises a practical scheme to enhance the real time performance of embedded Linux.The remote supervisory system for soot-measuration instruments has been completed, and it's validated in the lab. In a word, it has a certain practicality, and is also a good example for other remote supervisory systems based on embedded Linux.