Research On Distributed Acquisition And Control System Based On CAN Bus Network

The field bus technology ,which has a lot of advantages such as opening, total digitalization, two-way and serial, nodal communication, etc, is gradually developed along with the speedily development of control technique, computer technology and communication technology and the extensive use and ageing of digital instrument.After analyzing and comparing to the main stream field bus and deeply understanding the developing actuality of measure control system throughout the world, through combination with the research subject of the voyage data recorder (VDR)'s data acquisition device , and use of CAN bus as the communication bus , and adoption of C8051F040, which integrated CAN controller and has the characteristics of higher velocity and rich peripheral interface ,author has designed the acquisition and control system based on CAN bus network, that takes data acquisition and switch control.This system's advantages are the better commonality, the high reliability ,the convenient extension and system configuration ,field supervision and download .This dissertation is surrounding data acquisition and the control and reliability of system ,carried out following main studies:(1) Study of data acquisition and controlIn order to strengthen the systematic commonality , the various inputs and outputs of this acquisition and control system have been taken into account and the systems analysis, have been studied designed the concrete application circuit respectively ,and this design possesses extremely strong reference value to other correlative systems(2) Study of system reliabilityIn order to strengthen the communication reliability of CAN bus, the automatic judgment system is studied and designed .This dissertation has given out the design scheme and the circuit schematic diagrams, which possess such characteristics as light electrical isolation, turnoff judgment of CAN bus and alarm.(3) Study of configuration of CAN bus's BaudAuthor has deeply studied CAN2.0B protocol and its principle. Combined C8051F040, this paper has studied the configuration of CAN bus's Baud carefully and thoroughly, and derived and discussed a formula, which has very important meaning to the configuration of CAN bus's Baud.In addition, in order to accomplish the function of system, software of measure control unit and supervision software have studied and designed respectively.