Nrog RS485 tes hauj lwm, muaj lub sijhawm uas tsis muaj tus neeg tsav tsheb nquag tsav tsheb npav. … Kev sib tw tag nrho lub network yuav tsum ib khub ntawm cov resistors: rub-up resistor rau +5V txuas rau "+" teeb liab kab, thiab rub-down resistor rau hauv av txuas nrog "-" teeb liab kab.
Koj tsis tuaj yeem coj mus rhaub RS485?
T-kais tsis tuaj yeem siv rau ntawm RS485 kabvim tias T-kais tsim spurs hauv kab uas yuav thaws cuam tshuam cov teeb liab rov qab mus rau tus so ntawm RS485 kab. … Qhov kev sib txuas lus RS485 yuav tsum nyob ntawm ib khub ntawm cov xov hlau, txuas txhua yam khoom siv hauv cov saw daisy.
Vim li cas thiaj txiav txim siab xav tau hauv RS485?
120 ohm network txiav tawm resistors tso rau ntawm qhov kawg ntawm RS-485 twisted-pair kev sib txuas lus kab pab tshem tawm cov ntaub ntawv mem tes teeb liab cuam tshuam uas tuaj yeem cuam tshuam cov ntaub ntawv ntawm kab. … Tab sis nyob rau tag nrho cov kev txiav tawm resistors yuav pab tau network kev ua tau zoo ntau dua li lawv yuav ua mob rau nws.
Yuav ua li cas tsis muaj kev nyab xeeb hauv RS485?
Failsafe biasing yog hais txog cov txheej txheem ntawm muab qhov sib txawv ntawm qhov sib txawv mus rau qhov txiav tawm, tsis siv lub npavtxhawm rau tswj hwm cov khoom xa tawm ntawm lub tsheb npav transceiver hauv lub xeev logic-siab. Cov txheej txheem no feem ntau yuav tsum tau siv thaum tsim cov khoom siv hluav taws xob hloov pauv tau siv los tsim cov tsheb npav network.
RS485 transceiver yog dab tsi?
Standard RS485 transceivers ua haujlwm dhau ib hom kev txwvvoltage ntau yam uas txuas ntxiv ntawm -7V txog 12V. Nyob rau hauv ib puag ncig kev lag luam lossis kev lag luam, kev ua txhaum hauv av, suab nrov, thiab lwm yam cuam tshuam hluav taws xob tuaj yeem ua rau cov hom hluav taws xob ntau tshaj qhov txwv no.
