1、1Rearch and Realization of Embedded Web ServerAbstract. Articles submitted Embedded Web Server based on Web management model, the main solution is the use of a Web browser to access a large number of non-Inter net equipment under limited resources and processing power, control, and management and ot
2、her issues. Enabling device networking and intelligent management, field programmable equipment online remote monitoring, management and maintenance functions can be achieved, providing reliable technology for the the network intelligent management of industrial production automation systems and sma
3、rt appliances, supported. Key words: Embedded Internet TCP / IP the WEB RMON Introduction Existence of different kinds of networks and network management method and model of diversity, making access difficult to manage for a large number of devices in the network, there is an urgent need to seek eff
4、icient and convenient network management model to adapt to the rapid development of network of the new situation with the rapid development of the Internet and Web, Web-based network 2management technology also came into being. 1.Web-based network management model Network management model of Embedde
5、d Web Server device is shown in Figure 1. Equipment Web-based network management solutions are mainly the following advantages: 1) geographic and system mobility: remote site using a Web browser management transparent access equipment information; 2) unified Webbrowser interface facilitates user con
6、trol and management of equipment, as well as understand the equipment information; 3) smooth link heterogeneous network platform: Web management applications independent of the platform through standard HTTP protocol multipleWeb of equipment integrated device between the transparent mobile and acces
7、s; 4) the use of Java technology to quickly upgrade version of the software. 2.Embedded Web Server device 2 Embedded Web Server device architecture In order to use the standard browser via convenient Internet access to field devices, it is necessary to give them embedded TCP / IP protocol stack, and
8、 Web Server, mainly to solve the problem of heterogeneous networks, network interconnection and management of non-Internet equipment. EWS 3is the basis thinTCP / IP protocol stack and ERTOS, built with SNMP and SMTP protocols, the device has a simple network management functions, and has been a qual
9、itative leap in the function, so that the device truly intelligent and networked the function through the network can access to the Internet on the device management and control, as shown in the EWS architecture shown in Figure 2. By any computer Web browser installed using the standard HTTP protoco
10、l can be accessed with the device, monitoring, management and control. Through real-time parameters in the network to understand the equipment and the control and management of equipment, to the introduction of network management. And SMTP mail server mechanism for timely notification in the event o
11、f a failure by way of Email managers, managers first time you can get the message, maintenance and management of the operation of equipment in order to better equipment. 3.Embedded Web Server implementation of the model 3.1 Embedded Web Server hardware structure of the model Embedded Web Server mode
12、l is made on the basis of the 8-bit microprocessor and Ethernet interface controller. The external set the SEEPROM memory, used to store user-written web pages and images. Through UART or I / O and field devices control 4line connected to the management and control of equipment. In addition, by conn
13、ecting to the ISA bus card chip external (Internet users) provide a method of access to non-Internet devices via the Ethernet interface. 3.2 Embedded Web Server design Embedded Internet is already a mature technology, and on top of this, the design of an EWS its specificity must be taken into accoun
14、t: 1) the maximum extent to meet customer requests and burst; 2) to ensure that customers on different operating systemsdevices to access the consistency, embedded devices and the Internet connectivity is guaranteed; 3) to provide a complete set of security mechanisms to ensure the safety of the equ
15、ipment; 4) online device parameters can be configured many new designtechnologies such as multi-threaded concurrency and synchronization gateway technology, security algorithms and thin TCP / IP protocol stack technology to better achieve EWS function to improve the performance of the main function
16、of the EWS model: 1) in response to multiplereal-time HTTP request for each client to establish a connection; 2) real-time monitoring of equipment, management, control, parameters on-line configuration and security mechanisms, including SSL, user name and password; 3) the use of SNMP can be achieved
17、management and 5maintenance of equipment; 4) intelligent alarm equipment failure. EWS is based on the basis of thin T CP / IP protocol stack is built to achieve the HTTP T CP and U DP protocol, it has the IP address of the function and the general sense of the Web Server through the network can acce
18、ss the device into the Internet any client can establish a connection through HTT P protocol with EWS, EWS provides a unified GUI interface between the Web browser and the device, and compatible with each other and all of the Web browser the device driver and task and can be channel Download to real
19、-time multi-tasking system, local customers as transparent monitoring, management, maintenance equipment internal situation. 3.3 Real-time multi-tasking operating system Real-time multi-task execution program is run directly in the core of the system above the device driver software, mainly to compl
20、ete the task management, inter-task synchronization and communication functions of the operating system, is responsible for task creation, deletion and scheduling, and provide an externalunified interface network protocol stack, an embedded file system (WFS) and I / O management is the peripheral mo
21、dule running on top of the system kernel. 63.4 thin TCP/ IP Protocol stack Embedded TCP / IP protocol stack, the preparation is the key to achieve the EWS ? Because embedded devices storage resources are limited, this require the program to write quality higher, in order to reduce the length of the
22、program binary code to improve execution speed, EWS needsa possible reduction of the TCP / IP protocol stack without losing its standards and mechanisms. 3.5 HTTP Server HTTP is used to transfer files the standard protocol based on the Internet .all HTTP protocol between the network supports two typ
23、es of requests: a simple request and and fully to request application layer mainly HTTP protocol, and device-level operation targetedsimple request can be achieved by the on-site equipment monitoring and dynamic driver download. Order to quickly response to the received data packet, the Web server t
24、ransmits it to the preprocessing calculation Thin TCP / IP protocol stack of the simple state machine, reducing the redundancy of data, greatly reduce the complexity. Using this method, you can save time the microcontroller packet processing, faster response to client HTTP request Web browser in ord
25、er to get a Web document issued to EWS HTTP link request 7mechanism of interaction between them is shown in Figure 3 shown. HTTP access process as shown in Figure 4. Users can submit data to a Web page embedded applications, notifies the server by running a URL request processing information, call t
26、he pages in memory, using CGI interpreter processes, and then return to the page, while taking advantage of Web page can perform control commands to the device. 4. Conclusion Embedded Web Server is ERTOS and thin technology built into the TCP/IP protocol stack. Embedded Web Server network and intell
27、igent management of real devices, online field-programmable devices, such as remote monitoring, management and maintenance functions are achieved.Study of Embedded Web Server for remote downloads, as well as from a field programmable device provides the possibility of diagnosis and maintenance and t
28、echnical support. Reference 1 Wilson A. The challenge of embedded int ernet J .Elect ronic Pr oduct Desig n , 1998, 12( 3) : 1- 2, 34. 2 Zhao H. Em bedded int ernet a inf ormat ion technologyrev olu ti on of 21 st century M . Beijing: T 8singhua Universit y Press, 2002. 27- 40. 3 Arlitt M F, William
29、son C L. Web server workload characterizat ion: the search for invariant sA . In : Proceedings of the ACM SIGMETRICS Conf erence C . Philadelphia: ACM Press, 1996. 347- 356. 4 Zhao H , Chen F M . Embedded int ernet architecture andest ablish of the ONDC module J . Jour nal of N ortheaster nUniv ersit y( Natur al Science ) , 1999, 20( 3) : 257- 260.
