Research On The Long Distance Transmission And Share Of Field Information Based On Internet/Intranet

The field equipment with network and intelligent controller, the function ofcontrol is the main characteristic of modem industry control system. DCS, Industry Ethernet and FieldBus represent the tendency of networked, integrated and node intelligent of control system.With the rapid development of Internet technology, Ethernet and TCP/IP protocol has already become the standards. Ethernet based on TCP/IP protocol can meet with the requirements of each part of control system, and the industry Ethernet begins to apply to the industry control field. Meanwhile, with the progress of manufacture technology, the cost of chips and sensors are lower and lower, and the function becomes stronger and stronger. So it makes the expense of the connection between the embedded microcontroller and the Internet is so low that it is accepted. The control network based on embedded Internet will have very wide application prospects in the future, and at the same time it indicates the development trend of a new control network.This paper regards embedded Internet as the object and the data sharing and transmitting based on technology of FieldBus is studied. In this paper, it probes into the transmit dataflow method in the network. On this basts it provides the scheme about the industrialized FieldBus. This scheme can meet with the general control precision; the purpose of obtaining the field control information that is to transform the field control information between the TCP/IP and the field bus protocol. The field bus gateway has these main characteristics as follows: enveloping TCP/IP protocol, DeviceNet protocol and CAN protocol etc., by setting the working parameter in application; transmitting data on the field bus among LAN; achieving sharing the information between the field and the long distance control. This gateway includes the control unit, the CAN node and the data server of remote terminal. The hardware system has finished. By testing, the system satisfies the industry field control conditions based on the demand of the I/O switch output and analog signals output analog the field equipment, the time of data transmission delays less than 20ms, the interval time between state inquiry and data reply is less than 5ms.