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20091220 4ZHAOMINGGONGCHENGXUEBAODec. 2009Vol.20 No.4DMX512LED黄以华1 廖世文1 刘燕林1 蔡如海2(1., 510275;2., 510275) :DMX512LED。DMX512DMX,。LEDAC-DCLED,,PWM256。,,,。、。:DMX512;;;DMX512-BasedControlSystemforFull-ColorLEDLuminairesHuangYihua1 LiaoShiwen1 LiuYanlin1 CaiRuhai2(1.DepartmentofElectronicsandCommunicationEngineering,SchoolofInformationScienceandTechnology,SunYat-SenUniversity,Guangzhou,Guangdong 510275,China;2.GuangzhouJoinmaxDisplayTechnologyCo,Guangzhou,Guangdong 510275,China)Abstract ThispaperpresentsaDMX512basedcontrolsystemforhigh-brightnessLEDfull-color-luminaire.ADMXDecoderisusedasarepeaterfordatatransport,torealizefrequencymodulationandsignalenhancement.Inthefull-color-luminaire,ahigh-efficiencyAC-DCconverterisusedtodrivetheLEDintegrateswithintelligentcontrolfunction.256-stepPWMisusedfortheLEDdimming.Distributedconnectmethodisusedbythesystem,whichmakethesystemquiteflexibletocontrolandthemaintenanceofthesystemmucheasier.Asingledatabusisdesignedtoreducethecablingcost.Thesolutionofthesystemcanbewidelyusedinmanylightingcontrolapplications,suchasstagelighting,outdoorDecorativelighting,etc.Keywords:DMX512;LightingControlSystem;PWM;LightEmittingDiodes＊(2008B090500049)(60871059)1 ,(LightEmittingDiodes,LEDs)、、、[1],。RGB,。[2]、[3]、LCD[4][5]。DMXDigitalMultiplex,。DMX512[6](USITT),DMX512。DMX512EIB-485-A,。250kpbs,44s,512,0～255,PWM。DMX512LED。:TCPIPDMX512();LEDDMX512(),DMX512;LEDAC-DCLED,PWMLED256;,;,TCPIP,、。2 2.1 LED1。、、LED。,DMX512,,。RS485,,。LED,。IP,250,13,156。,、、。1 LED2.2 DMX512DMX512DMX,,DMX[6]2。(BREAK)、(MBB,MarkBeforeBreak)(MAB,MarkAfterBreak)。DMX512,MAB、BREAKMBB:,0≤MBB1s,BREAK≥88us,176us,12us≤MAB1s。513,11、82。1SC(StartCode),,00H,,。,DMX,。4us,250kbs。2 DMX,11～56;257～112,3113～168。DMX512,DMX512512。504,49204:DMX512LED3(RGB),LED。LEDLED,LED。DMX5123。3 DMX5123 3.1 LEDDMX512,DMX。,,,。4。4 ,RS485TTL,,,。,,DMX512,TTLRS485,。。,DMX512。,、LED,。LEDPWM。LED,PWMLED。LED5。5 LED3.2 LED、、。LED,,,5。,,4(D、N、L、G)。6。,MCUTX1TTL,LM717124V,pF,。BUF634,。BUF634[7]250mA,(≤10)。,56,200,,。24V,TTL,50 200912 MCUUARTRX2。,TX2TTL,MOSFET。TX2MOSFET,,BUF63424V,TTL,MCU,TX2,MOSFET,TTL,MCU。,,。6 3.3 LEDPWMLEDSupertexLEDHV9910B,7。HV9910B[8]8-450VDC,、。,。LEDRT:tosc(μs)=(RT(kΨ)+22)25(1) f=51.2kHz,RT470kΨ。7 AC-DCHV9910BMOSFET。HV9910B,LEDCS,250mV,HV9910BMOSFET,。MOSFET。MOSFETf,VDC,LED()VO,LEDIo,Vd,L,:Ton=1f×VOVDC(2)Ldidt=ΔU(3)ΔU=Vo-Vd≈VO(4) LED,LED30%,didt=Δi=0.3×IO(5) (2)、(3)、(4)、(5)L=VO×1-V0VDC0.3×IO×f(6) (6),。(6),MOSFET,,LED;,,。(PWM)LED。LED。PWM[1]:PWM,LED。PWM51204:DMX512LEDt,T:D=tT(7) IO,LEDUO,LED:I=D×IO(8) :P=D×IO×UO(9) f=1T,LED,LED:L=1T∫f(IO)dt=tT·f(IO)=D·LP(10) ,L;LP;f(IO)LED。PWM8。LEDMOSFET,LED;MCUPWM,DMX。LED256,DMXN(0～255),D=N256。PWM[9],fPWM。fPWM(120Hz)LED;,,fPWMLED,。,LED,51.2kHz。fPWM200Hz256。。LED2,8 PWM():256×256×25616777216。3.4 9。LEDMCUUART,DMX,。,。,、,。,DMX,,,,。,。9 52 200912 。DMX512250kbs,512,44s[6]。,168。fkbs,T=((MBB+BREAK+MAB)+168×4×11)×(250f)(us),1000000T。,(),,2。,,。4 DMX512LED,,。IP,,。,,,LED,。,DMX512。[1],..:.2006[2]AndrewE.Moe1,NaureenBanani,LindaA.Lee.BrianMarquardt,andDeniseM.Wilson.EnhancedFluorescenceemissionusingaprogrammable,reconfigurableLED-arraybasedlightsource,”Proc.Int.ConfEngineeringinMedicineandBiologySociety,2004.3,2090-2093.[3]KarenSaucke,GuntramPausch,JǜrgenStein,Hans-GeorgOrtlepp,PaulSchotanus.StabilizingScintillationDetectorSystemswithPulsedLEDs:AMethodtoDerivetheLEDTemperaturefromPulseHeightSpectra.IEEETrans.nuclearScience,2005,52(6),3160-3165.[4]T.-F.Wu,C.-C.Chen,C.-Y.Wu,P.-C.LuandY.-R.Chen.SequentialColorLEDBacklightDrivingSystemforLCDPanelswithAreaControl.PowerElectronicsSpecialistsConference,2007,2947-2952[5]FengTian,XiangWu,JingaoLiu.ResearchandRealizationofLEDDisplaySystemBasedonCombiningCANBuswithDMX512Standard.InternationalConferenceonAudio,LanguageandImageProcessing,2008,813-818[6]YAmericanNationalStandardE1.11-2004.EntertainmentTechnologyUSITTDMX512-A,AsynchronousSerialDigitalDataTransmissionStandardforControllingLightingEquipmentandAccessories,EntertainmentServicesandTechnologyAssociation,USA,2004[7]Burr-BrownInc.“250mAHIGH-SPEEDBUFFER.”BUF634Datasheet,2007.[8]SupertexInc.“UniversalHighBrightnessLEDDriver.”HV9910BDatasheet,2007.[9]SamehSarhanandChrisRichardson.NationalSemiconductor,Amatteroflight,Part4—PWMdimming,2007.302009101630。、。。,、,。,,30,、、,。993,121,8、8。,2930。,、、、、、()。。。53204:DMX512LED