The Research Of Industrial Ethernet Wireless Extention

Fieldbus is a digital network which applied in process control, two-way, multi-node, bus-structure are the features of this digital communication network..But facing the measurement and control of some mobile, rotated or the dangerous objects in the production field of industry environment, wired physical medium is hard to join; with the development of industrial ethernet, multilevel network need to combine the ethernet and fieldbus; the cost of industrial wire layout is high. It is the best scheme to slove the problem by applying the wireless ethernet technical to the fieldbus.This paper is to research CANBUS bus. On the foundation of analysing CANBUS bus and IEEE 802.11x, the research apply WLAN IEEE 802.11b to the industrial CANBUS fieldbus as extended wireless CANBUS network. By considering existing technical compatible problem, easy realization problem and the requirement of the other requirements, the research determine the technical goals of wireless CANBUS network.This paper designes the network configuration of wireless CANBUS network - Virtual Ring Extended( VRE), wired nodes and wireless nodes may run in a same CANBUS network; analyses how to guarantee high performance and the high speed of physical layer using DSSS technology; designs the special AP node - AP-IWU that realizes the smooth bridge of wired/wireless net; realizes the combination of the CANBUS and IEEE 802.11b in apply layer; designs Finite State Machine(FSM) of the master node and the slave node, verifies the accessibility of FSMs; at last, the real-time of the network system is discussed. Aiming at the characteristic of wireless channel, the research puts forward the algorithm of scheduling data and determines network transmission delay of the period data and Time-critical data in wireless CANBUS.