Design And Implementation Of Passenger Information System Controller Based On VLYNQ

With the rapid development of urban rail transit,the subway has become a safe, efficient and convenient public transit. Passenger Information System(PIS), one of the most important part of subway control systems, is installed in every subway almost.The PIS contains three parts-broadcasting and voice intercom system,passenger information display system and closed circuit television.There are lots of devices installed in the PIS and they are controlled by the PIS Controller.The PIS Controller always needs to fulfill the data processing and logic operation.VLYNQ is a classic proprietary interface developed by Texas Instruments(TI) and it is used for broadband products, such as WLAN and modems, VOIP processors and audio and digital media processor chips.The VLYNQ is such a full-duplex serial communications interface with high transfer speed that enables the extension of an internal bus segment to one or more external physical devices.Nowadays the increasingly demands of proprietary interface in the PIS Controller are obvious,taking advantage of the VLYNQ,a new design is transplanted in the PIS Controller.Considering about the characteristics of the VLYNQ,a scheme about the designing and implementing of the PIS Controller is raised.In order to describe the whole scheme,the function and technical advantages of the VLYNQ is introduced first.Then this thesis analyses the techniques encountered when developing the Linux device driver programs.Besides,the whole demand of the PIS Controller is narrated.Before the implementing of this design,the overall architecture of the PIS Controller drivers is proposed.And then this thesis gives the key implements of the drivers.In the end,an experiment is introduced to test the correctness of the drivers when the programs are compiled.Now the PIS Controller based on the VLYNQ is successfully used in one subway project overseas and the running situation is stable.