Study On Wireless Transmission Applied To Bus Of Industrial Control System

Wireless transmission applied to bus of industrial control system is a communication mode that some part of system bus adopts wireless mode to transmit. The mode adapts to data transfer of mobile object, Automatic Reading Meter, Building Automation, smart house, and so on, which is an application foreground widely. Because of good foreground, it is focused on.The thesis introduces the conception of wireless transmission applied to bus of industrial control system in brief, compares several sorts of wireless system, and analyses actuality and trend of this system. According to its actuality and trend presently, the thesis accomplished some tasks as fellows:1. An application model of wireless transmission applied to bus of industrial control system is stated, which transfers data by semiduplex of asynchronous & serial method. Communication protocol is designed according to application model. To improve anti-jamming of system, static noise and dynamic noise are analyzed to design anti-jamming project.2. According to application model, hardware is selected firstly, and then particular circuit is designed in two sides of peripheral circuit of nRF401 and circuit of system. Practically, the system capabilities are as follows:(a) Data may be transferred reliably when wireless module lies at wide site without strong noise inside 100 meters. When wireless channels are disturbed by strong magnetic field suddenly, system may check error frame.(b) Data may reliably be transferred through 4 blocks without strong disturb insideSO meters.(c) When data is transferred beyond 150 meter or through 6 blocks inside 50 meters, reliability of data may descend, but receiver may check errors.3. According to system model and hardware circuit, system software is designed. After analyzing software model of CRC firstly, software design is accomplished through looking up table in CRC-16. Then system design of software is achieved in order to lay out software function as a whole. System software includes software of microprocessor and test of DTE. The thesis supplies particular flow chart of software and its illumination.