RS-485 Half-Duplex EVM User's Guide (Rev. B) - …

1 User's GuideSLLU173B October2012 RevisedJune2013RS-485 half -DuplexEvaluationModuleThismanualdes cribestheRS-485 half -DuplexEvaluationModule(EVM).ThisEVM helpsdesignersevaluatethedeviceperforman ce,supportingthefastdevelopmentandanalys isofdatatransmissionsystemsusinganyofthe TIRS-485half-duplexdevicesin :LeftasReceiverEVM, October2012 RevisedJune2013RS-485 half -DuplexEvaluationModuleSubmitDocumen tationFeedbackCopyright 2012 2013,TexasInstrumentsIncorporatedRTRTABD DERREDRVccRFSRFSABDDERREPOLCORDRABDDERPO LCORDRREABDDERPOLCORDRREM asterSN65 HVD82 SlaveSN65 HVD888 SlaveSN65 HVD888 SlaveSN65 HVD888 Cross-wirefault 0 the8-pinSOIC packagehaverobustdriversandreceiversin a , differentialdriveranda differentialreceiver,whichoperatefroma busportsuitableforhalf- duplex (two-wirebu s)communication,andallfeaturea ' :ThisEVMcomeswithouta ,8-pinSOICRS-485transceiverandsolderit (SeeFigure1). TheSN65 HVD888transceivercorrectsa wrongbussignalpolaritycausedbya : a failsafebiasingnetworkmustbeimplemented( atthemasternode)tosetlogicreferenceandde finethesignalpolarityofthebus, a slavenodemusthaveitsreceiverenabledandit sdriverdisabled(RE= DE= Low), thebusmustbeidlingforthefailsafetime, ,thepolaritycorrectionis completeandis appliedtoboth, :Datastreamsofconsecutive0 s or1 s withdurationsexceedingtFS-mincanaccident lytriggera October2012 RevisedJune2013 SubmitDocumentationFeedbackCopyright 2012 2013,TexasInstrumentsIncorporatedNOTE.

2 R2, R3, R4 - DNIA_2B_2 DEDB/RER_1 RADUT_VCCEARTH_GNDDUT_GNDDUT_GNDEARTH_GN DDUT_GNDEARTH_GNDEARTH_GNDEARTH_GNDEARTH _GNDDUT_GNDDUT_VCCDUT_GNDDUT_GNDEARTH_GN DDUT_GNDEARTH_GNDDUT_GNDEARTH_GNDDUT_VCC DUT_VCCDUT_VCCDUT_VCCVCM_BVCM_ADUT_GNDEA RTH_GNDDUT_VCCVCM_BDUT_GNDEARTH_GNDEARTH _GNDDUT_GNDEARTH_GNDDUT_VCCVCM_ADUT_GNDV CM_AVCM_BEARTH_GNDEARTH_GNDEARTH_GNDEART H_GNDEARTH_GNDEARTH_GNDEARTH_GNDEARTH_GN DDUT_GNDDUT_GNDDUT_VCCDUT_GNDDUT_GNDDUT_ GNDDUT_GNDDUT_GNDR7 UNINSTALLEDTB23 PIN_TERMINAL_BLOCK123R250 OhmsR350 OhmsD3 RED LED Diode12D2 GREEN LED Diode12R450 OhmsC11uFR5120 OhmJMP9 Header 4x11234U1SN65 HVD7xR1/RE2DE3D4 GND5A6B7 VCC8R111k 3x1123 JMP14 Header 3x1123 JMP4 Header 4x11234C41uFC9 UNINSTALLEDJMP10 Header 4x11234 JMP8 Header 4x11234 JMP3 Header 4x11234R6 UNINSTALLEDC7 UNINSTALLEDD1 BLUE LED OhmsJMP7 Header 4x11234R11k OhmsJMP13 Header 3x1123 JMP1 Header 4x11234 JMP6 Header 4x11234TB13 PIN_TERMINAL_BLOCK123 JMP11 Header 3x1123R90 OhmC8 UNINSTALLEDR80 OhmR100 (JMP5is omitted) :Theexamplesin thisdocumentshowa ,theusermayneedtoprovidea 5-Vsignalgeneratorinputand5-Vpowersupply .

3 Pin1 (EARTH)is a secondgroundpinthatallowsapplyinganexter nalvoltagebetweenGNDandEARTH tosimulatecommon-modevoltageconditions. Pin2 (GND)is alsoconnectstovariousjumpersontheboard. Pin3 (VCC)is connectedtothepositiveoutputofa regulatedpowersupplyunit(PSU)asit October2012 RevisedJune2013RS-485 half -DuplexEvaluationModuleSubmitDocumen tationFeedbackCopyright 2012 2013, Ch2 JMP41234 VCC123 JMP14D - ,ignorethecommon-modesimulationandconnec tEARTHtoGNDthroughawire-bridgebetweenpin 1 andpin2 ,orheadersthroughwhichthecontrolanddatas ignalsfortheRS485 half -DuplexEVMareapplied,JMP1,andJMP11to JMP14areprobepoints, resistors,R2,R3,andR4, , indicatingthatthesecomponentsarenotassem bled. Becausesignalgeneratorshavea typicalsourceimpedanceof50 , theiroutputsignalistwicetherequiredsigna lvoltage,andassumesthattheon-board50- ;however,thisvoltagedivideractionis notaccomplished, givesanexampleforenteringa adjustedtomatchthedeviceVCCpowersupplyre quirements.

4 Thegenerator sgroundterminalis connectedwithpin3,andthesignaloutputterm inalwithpin2 measuredthroughanoscilloscopewithitssign alinputconnectedtopin1 anditsgroundwireconnectedtopin2 ,mustnotreceivea ,it representsthereceiveroutput,R, , ,forproperoperation,it mustbeassuredthatthehigh-levelinputvolta geVIH 2 V andthelow-levelinputvoltageVIL October2012 RevisedJune2013 SubmitDocumentationFeedbackCopyright 2012 2013, maximumoutputsignallevel,basedontheVCCre quirementsofyourselectedRS-485device, ofTB1andobservetheblueLED(D1) ,R,willturnontheredLED(D3),andlogichigha tthedriverinput,D,turnsonthegreenLED(D2) .If D is leftopen,aninternal100-k ,duetothesmallinputcurrent, , ,thereceiverenablepin(RE)mustbeatlogiclo wpotentialandthedriverenablepin(DE) (VOD= VA VB)onthebuswires,A ,it is possibletosensethedatatrafficin ,PSU-ground,throughthewire-bridgefrompin 1 topin2 attheterminalblock,TB1,whilepin3 (VCC),in thisexample,is power-supplyunit(PSU).

5 5 SLLU173B October2012 RevisedJune2013RS-485 half -DuplexEvaluationModuleSubmitDocumen tationFeedbackCopyright 2012 2013, -7V to +12 VScopeCh1 Ch2 Ch3 providedbythewire-bridgefrompin2 topin3 atJMP2,andthehighpotentialforDEthrougha wire-bridgefrompin2 topin1 andpin3 measuredviachannel1,whichis connectedtopin1andpin2 measuresthereceivedataatJMP11,andchannel s3 and4 thebusvoltages,VAandVB, ( RS-485 )specifiesthreemaximumloadparamet ers:a maximumdifferentialloadof60 , amaximumcommon-modeloadof375 foreachbuswire,anda receivercommon-modevoltagerangefrom 7 V to+ reflectstheserequirementsthroughR5,R8,R9 ,andVCM. thepreviousexample,thefollowingboardchan gesneedtobeimplementedtoreflectmaximumlo adconditions:6RS-485 half -DuplexEvaluationModuleSLLU173B October2012 RevisedJune2013 SubmitDocumentationFeedbackCopyright 2012 2013, Ch3 Ch2 Ch1 BAPSU2 SignalGeneratorJMP412 VCC34 DJMP312 VCC34 JMP212 VCC34 Ch3 Ch2 replaceR5(120- default)with60 replaceR8andR9(0- default)with375 connectpin2 ofJMP7withpin1 andpin3 withpin4 replacethepreviouswire-bridgeatTB1witha secondpowersupplyunit(PSU2)andconnectthe groundterminalsofboth,PSU1andPSU2witha wire-bridge,asshownin , connectthegroundterminalofPSU2withpin1 ofTB1(EARTH).

6 LeftasReceiverEVM,RightasTransmitterEVM7 SLLU173B October2012 RevisedJune2013RS-485 half -DuplexEvaluationModuleSubmitDocumen tationFeedbackCopyright 2012 2013, October2012 RevisedJune2013 SubmitDocumentationFeedbackCopyright 2012 2013,TexasInstrumentsIncorporatedEVALUAT IONBOARD/KIT/MODULE(EVM)ADDITIONALTERMST exasInstruments(TI)providestheenclosedEv aluationBoard/Kit/Module(EVM) , theUser s Guide ,theboard/kitmaybereturnedwithin30d aysfromthedateofdeliveryfora ,EXPRESSED,IMPLIED,ORSTATUTORY, ,NEITHERPARTYSHALLBELIABLETOTHEOTHERFORA NYINDIRECT,SPECIAL,INCIDENTAL, 's Guideand,specifically,theWarningsandRest rictionsnoticein theUser's 's environmentaland/orsafetyprograms, grantedunderanypatentrightorotherintelle ctualpropertyrightofTIcoveringorrelating toanymachine,process,orcombinationin varietyofcustomersforproducts,andtherefo reourarrangementwiththeuseris ,customerproductdesign,softwareperforman ce, theEVMUser s Guideand/orEVMitself,thisEVMand/oraccomp anyinghardwaremayormaynotbesubjecttotheF ederalCommunicationsCommission(FCC)andIn dustryCanada(IC)

7 ,thisevaluationboard/kit/moduleis intendedforuseforENGINEERINGDEVELOPMENT, DEMONSTRATIONOREVALUATIONPURPOSESONLY andis notconsideredbyTItobea finishedendproductfit generates,uses,andcanradiateradiofrequen cyenergyandhasnotbeentestedforcompliance withthelimitsofcomputingdevicespursuantt opart15ofFCCorICES-003rules, ,in radioUserPower/FrequencyUseObligations: Thisradiois intendedfordevelopment/professionaluseon lyin (s) is theuser s soleresponsibilitytoonlyoperatethisradio in ,whichis subjecttothefollowingtwoconditions:(1)Th isdevicemaynotcauseharmfulinterference,a nd(2)thisdevicemustacceptanyinterference received, 's EVMdevicesThisequipmenthasbeentestedandf oundtocomplywiththelimitsfora ClassA digitaldevice, operatedin a ,uses,andcanradiateradiofrequencyenergya nd,if notinstalledandusedin accordancewiththeinstructionmanual, a residentialareais likelytocauseharmfulinterferencein EVMdevicesThisequipmenthasbeentestedandf oundtocomplywiththelimitsfora ClassB digitaldevice, a ,usesandcanradiateradiofrequencyenergyan d,if notinstalledandusedin accordancewiththeinstructions, ,thereis noguaranteethatinterferencewillnotoccuri n a ,whichcanbedeterminedbyturningtheequipme ntoffandon,theuseris encouragedtotrytocorrecttheinterferenceb yoneormoreofthefollowingmeasures: Reorientorrelocatethereceivingantenna.

8 Increasetheseparationbetweentheequipment andreceiver. Connecttheequipmentintoanoutletona circuitdifferentfromthattowhichthereceiv eris connected. INDUSTRYCANADAC ompliantThisClassA orB s (s).Operationis subjecttothefollowingtwoconditions:(1)th isdevicemaynotcauseinterference,and(2)th isdevicemustacceptanyinterference, ,thisradiotransmittermayonlyoperateusing anantennaofa typeandmaximum(orlesser) ,theantennatypeanditsgainshouldbesochose nthattheequivalentisotropicallyradiatedp ower( )is thislist,havinga gaingreaterthanthemaximumgainindicatedfo rthattype, riquedela classeA ouB estconforme la mentapprouv s parla partieresponsabledela conformit ontpuviderl autorit del'utilisateurpouractionnerl' sentappareilestconformeauxCNRd' 'exploitationestautoris e auxdeuxconditionssuivantes: (1)l'appareilnedoitpasproduiredebrouilla ge,et(2)l'utilisateurdel'appareildoitacc eptertoutbrouillageradio lectriquesubi,m mesi le brouillageestsusceptibled'encompromettre le tachablesConform ment la r glementationd'IndustrieCanada,le pr sent metteurradiopeutfonctionneravecuneantenn ed'untypeetd'ungainmaximal(ouinf rieur)approuv pourl' butder duirelesrisquesdebrouillageradio lectrique l'intentiondesautresutilisateurs,il fautchoisirle typed'antenneetsongaindesortequela puissanceisotroperayonn e quivalente( )

9 Ned passepasl'intensit n cessaire l' tablissementd' sent metteurradioa t approuv parIndustrieCanadapourfonctionneravecles typesd'antenne num r s dansle manueld usageetayantungainadmissiblemaximaletl'i mp dancerequisepourchaquetyped' 'antennenoninclusdanscetteliste,oudontle gainestsup rieuraugainmaximalindiqu , sontstrictementinterditspourl'exploitati ondel' ImportantNoticeforUsersofthisProductinJa pan ThisdevelopmentkitisNOTcertifiedasConfir mingtoTechnicalRegulationsofRadioLawofJa panIf youusethisproductin Japan, a shieldedroomoranyothertestfacilityasdefi nedin thenotification#173issuedbyMinistryofInt ernalAffairsandCommunicationsonMarch28,2 006, oftheMinistry s RuleforEnforcementofRadioLawofJapan, RadioLawofJapanwithrespecttothisproduct, ,pleasedonottransferthisproduct, youcouldnotfollowtheinstructionsabove, (address)24-1,Nishi-Shinjuku6 chome,Shinjuku-ku,Tokyo, 1.

10 6 1 1 18 3 28 173 2. 3. (EVM)WARNINGS,RESTRICTIONSANDDISCLAIMERS ForFeasibilityEvaluationOnly, ,thisEVMis nota is intendedsolelyforuseforpreliminaryfeasib ilityevaluationinlaboratory/developmente nvironmentsbytechnicallyqualifiedelectro nicsexpertswhoarefamiliarwiththedangersa ndapplicationrisksassociatedwithhandling electricalmechanicalcomponents, shouldnotbeusedasallorpartofa , ,Stateandlocalregulatoryrequirements(inc ludingbutnotlimitedtoFoodandDrugAdminist rationregulations,if applicable)whichrelatetoyourproductsandw hichrelatetoyouruse(and/orthatofyourempl oyees,affiliates,contractorsordesignees) oftheEVMforevaluation, ,andalsotoassurethesafetyofanyactivities tobeconductedbyyouand/oryouremployees,af filiates,contractorsordesignees, ,youareresponsibletoassurethatanyinterfa ces(electronicand/ormechanical)