Fieldbus-based Remote Data Exchange System

With the development of technology such as controlling, computer, communication, network, the field employed in information exchange is covering rapidly each level from the on-the-spot apparatus of the factory to central control, management. Administrator carry on real-time, dynamic (including long-range) data interchange to the apparatus running situation become more and more urgent.In the realization of long-range data interchange, the subject research mainly CAN bus and communication mechanism of Ethernet, adopting the subminiature controller of high performance to have designed the embedded gateway of transparence, and realize the protocol by software method. In fact, Choose SX52 subminiature controller as the processor in concrete application. Ethernet network drives CMOS RTL8019AS by coupling insulate filter HR61101G and RJ45 insert to Ethernet. It supplies the platform for the data exchange between the management layer and industry control layer.The subject is mainly the interchange of TCP/IP protocol and CANfield bus protocol in the course that realizes the communication procedure. Brower/server (abbreviated as B/S) is adopted in the subject as development mode. But because the resources of SX SCM are limited, the task of having a look around of the real-time, dynamic data of programming realization is relatively heavy with the server that the SCM puts up. And operate procedure in sewer, pace is limited too, in addition, webpage interface or procedure structure change unilaterally will lead to the face that the whole system is revised totally; systematic flexibility and expansibility are bed. In the design, if only utilize B/S to visit way, its function is difficult to finish totally. In order to overcome traditional draw back of B/S visit mode, have done following two points to improve:1. Adopt the programming of Socket, realize some server procedures to run on the customer end, and realize the dynamic webpage to reveal real-time data on the customer end browser.2. No longer write HTML language into the assembler, untie in the end of the browser into WebPages, than utilize EEPROM24C256 that embedded web server expands to link with SX52, is used for storing web file to have a look around. When the browsers and web servers are mutual, utilize HTTP protocol to confirm by unifying the resource positional URL what recourses. Web server should offer for browser.