Research On Networked Instrucments

In our era of information technology, many traditional instruments can't satisfy the need of people for information. It has become one of the hottest topics in the development and application of instrument industry that how to extensively employ the hard and soft resource in Internet. Network based instruments come into being in this environment. Like common instruments, network based instruments can measure, control, save, display and transport many physical quantity. Furthermore, through Internet, authorized users can do many manipulations to the instruments remotely, such as monitoring, supervising, history retrieving and fault diagnosis. Therefore, using network based instruments, people can share and obtain information all around the world, free from the limitation of time and location. The design method of network based instruments, including Ethernet hardware development and related software application design, presented in this thesis, has been applied in the C3000 process controller manufactured by SUPCON INSTRUMENT, to realize multi-point real-time communication, remote maintenance, and software update, etc.After analysis of several Ethernet interface design, a scheme of internally installed Ethernet card was accepted. To meet the demand of instrument extensibility, CPLD, together with RAM, was originally used to communicate internal data between the main board of instruments and Ethernet card. How to address in large-scale spaces and realize TCP/IP protocol stack in resource-limited condition, is also taken into account. Based on the communication by Ethernet, embedded Web Server, remote maintenance of instruments, remote software update of instruments, etc, are studied and designed. The network based C3000 is finally realized.