Tom qab hloov qhov kev txiav tawm resistor nyob rau hauv ib tug kub khiav kev sib txuas lus system, tsis muaj ntxiv "configuration" yog yuav tsum tau; nws ua haujlwm raws li qhov impedance- txuam feem ntawm lub cev txheej thiab ua tau zoo tau txais txiaj ntsig ib zaug raug teeb tsa. Lub ntsiab lus tseem ceeb yog kom ntseeg tau tias 120Ω resistors tsuas yog ntsia ntawm ob qhov kawg ntawm lub npav; txuas lawv mus rau nruab nrab cov nodes yog nruj me ntsis txwv tsis pub, vim qhov no yuav ua rau kev sib txuas lus anomalies.
1. Tsis muaj Software lossis Parameter Configuration yuav tsum tau
Termination resistors yog cov khoom siv kho vajtse nkaus xwb thiab tsis koom nrog kev teeb tsa ntawm qhov tsis xws li kev sib txuas lus, baud tus nqi, lossis chaw nyob ntawm cov khoom siv.
Tom qab hloov, tsis muaj cov ntawv qhia zaub mov yuav tsum tau kho nyob rau hauv lub PLC, HMI, los yog kub khiav maub los.
Tsuav yog qhov kev sib txuas ntawm lub cev muaj tseeb (ib qho 120Ω resistor ntawm txhua qhov kawg), lub kaw lus yuav cia li phim impedance raws li lub zog- nce.
Tswv yim: Yog hais tias kev sib txuas lus tseem txawv txav tom qab hloov, ua qhov tseem ceeb rau kev daws teeb meem ntawm qhov chaw teeb tsa thiab tus nqi tiv thaiv es tsis xav tias "tsis tau teeb tsa."
2. Cov khoom sib txuas ntawm lub cev uas yuav tsum tau kuaj xyuas
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Xyuas yam khoom |
Kev xyaum raug |
Cov piv txwv tsis raug |
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Qhov chaw teeb tsa |
Nruab tsuas yog nyob rau ntawm ob qho khoom siv nyob rau ntawm qhov kawg ntawm lub npav |
Nruab termination resistors ntawm intermediate qhev pab kiag li lawm |
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Resistance Value Verification |
Siv multimeter los ntsuas qhov sib npaug ntawm cov ntsiab lus A thiab B (yuav tsum yog ≈60Ω) |
Kev ntsuas tus nqi yog 120Ω (tsuas yog ib qho kawg ntsia) lossis ∞ (tsis muaj qhov cuam tshuam) |
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Txoj kev xaim |
Siv ib qho "daisy-chain" (tes-hauv- tes)) txuas rau kev sib txuas lus cables |
Siv lub hnub qub -topology los yog T-txoj kab hluav taws xob |
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Tiv thaiv Grounding |
Hauv av daim thaiv kab thaiv ntawm ib qho kawg * (feem ntau ntawm chav tswj sab) |
Hauv av ob qho tib si xaus ib txhij, tsim lub voj hauv av uas ua rau muaj kev cuam tshuam |
Lus Cim Tshwj Xeeb: Qee qhov ntse modules (xws li, RSM485PHT) feature ua tau -nyob rau hauv, switchable termination resistors. Koj yuav tsum xyuas seb cov no twb tau qhib los ntawm jumpers lossis DIP keyboards kom tsis txhob tsim cov kev sib txuas tsis sib xws sab nraud.
3. Peb-Yuav tsum muaj pov thawj kauj ruam tom qab hloov
① Ntsuas qhov tsis kam (Power Off)
Kaw lub kaw lus thiab txiav fais fab; ntsuas qhov tsis kam ntawm kab A thiab B.
Tus nqi ib txwm: ≈60Ω (Ob 120Ω resistors nyob rau hauv parallel)
② Saib Waveforms (Power On)
Txuas lub oscilloscope los soj ntsuam cov teeb liab sib txawv.
Ib txwm Waveform: Ib lub voj voog ntshiab, tsis muaj suab nrov lossis overshoot.
③ Saib xyuas cov cav (System Running)
Saib xyuas PLC/SCADA cov ntaub ntawv sib txuas lus tsawg kawg yog 4 teev.
Kev coj cwj pwm tsis zoo: Tsis muaj qhov tsis zoo xws li "Kev Sib Txuas Lus Sijhawm," "CRC yuam kev," thiab lwm yam.
Kev lees txais: Tag nrho peb cov kauj ruam yuav tsum ua tiav kom paub meej tias qhov kev hloov pauv tau ua tiav.
