Research On Consumptive Terminates Of One Card System In Digital Campus Based On Can

CAN is a kind of serial communication bus based on event-triggered mechanism. In order to fit for the communication features of one card pass system in digital campus, the system based on CAN is implemented which is to expand the capacity of terminates, make full use of the Ethernet resource exiting in campus, exploit the advantage of Ethernet in wireless development and adjust to information-integrated trend of the large-scale campus.The distributed consumptive subsystem is resolved from one card pass system in digital campus, and then the basic conditions of alternation is built up which is between terminates and the data center on the foundation of aricheteture, network architecture, function lists and protocol stack design. After planning the resources of peripherals and memory, the aspect-oriented agile development model is designed.In the process of implementation of software on-line update, the traffic control mechanism is designed found on the back off principle. The data acquisition and processing software running on the communication manager of data center is implemented on the basic of CANET-100 redevelopment.The embedded database is discussed to support the consumptive data closed-loop.On the basis of CAN protocol, the automatic recovery of bus errors is considered, like with the construction of the bus system based on CAN, the configuration of the bit scheduling parameters and the pivotal factors of the fusion between CAN and Ethernet. The linear mixed bus scheduling algorithm is designed on the foundation of the structured ID of CAN frame and the components of one card pass system, and then combine it with CAN CSMA/CA model generated by network simulation system OPNET to analyse and compare efficiency and stability.