Design And Implementation Of Active Star Coupler For Multifunction Vehicle Bus

This thesis introduces a kind of active star coupler based on the multifunction vehiclebus.The star coupler as the middle of the train communication network equipment achievesthe regeneration and forwarding of the train bus signal, and it also have the function ofdevice staus response that complys with IEC-61375standard protocol of Class1device.This design of MVB star coupler not only contains five optical glass fiber channels, italso has an electrical middle distance and electrical short distance channel. Each channel isdesigned with redundancy, and forwards bus data mutually. The forwarding delay is muchsmaller than6μs. Star coupler can be reported to bus master device the running status ofseven channel, and separates disturbing channel timly from bus in case of error happens.After a large number of theoretical analysis and practical demonstration, according tomultifunction train bus active star coupler of design parameters, the project decides to usehigh-performance FPGA to complete logical process that including bus data forwarding,frame coding and decoding, device status response, redundant processing and isolationcontrol.This thesis first introduced basic principles and system structure of MVB active starcoupler, then designed overall scheme of the system based on the requirements, andclassified hardware and software modules for star coupler. Next, the thesis discesses thespecific hardware design, FPGA logic design of implementation mechanism for coupler indetail.Multifunction train bus active star coupler’s design and implementation has beensuccessfully completed and connected to train communication network for practical test.Coupler runs stably and in accordance with design requirments.