Signal Acquisition And Processing System Based On CAN BUS

Fieldbus is a kind of computer network in the automatization field. As one of the most promoting field bus,CAN BUS have many advantages,such as outstanding real time ability,high reliability and low price.So it has become one of the developmental hotspot in automatization field gradually.The main research object in this thesis is the distributed data acquisition and communication system based on CAN BUS,and prepare to use it in the industry field.After analyzing the CAN BUS protocol 2.0B,the author design the data acquisition and processing module which contains the CAN BUS interface with structurely method .The hardware design of the aptitude nodes use high speed singlechip c8051f040 as its core.It has already integrated AD acquisition and DA output submodules.withal, extending some other modules such as CAN BUS communication and address coding.Under the Silicon Laboratories IDE which is including the Keil c51 compiler,the author accomplished the entire software program with modularization methods.The submodules contain analog voltage acquisition,CAN BUS communication,analog voltage output,LCD display, matrix keyboard scan,port input and output.Use the main function's multitask mechanism to transfer every subtask by time-sharing,and make use of some skills such as overacquisition to do some simple disposal in order to enhance the accurate of the acquisit signal.These measures lighten the burden of the network as well as enhancing the efficiency of the system.The whole system is consist of two bottom nodes and one PC which contain the CAN BUS communication card Use the principal and subordinate structure, carry out the bidirectional communication via the card.Thus,PC can receive the parameter from the industry field in time.Therefore,it can guarantee the real time ability of controlling and testing.The application layer protocol is defined by author in order to tally with the system.The whole system workes stably now.It means that the design of this system is achieved the demand in industry field.