Yuav Ua Li Cas Qhov txawv Ntawm RS232, RS485, RJ45, thiab Modbus? (1)
Xav txog qhov DC fais fab mov, nws cov qhov hluav taws xob tso zis interface muaj peb tus pins, uas yog qhov zoo, tsis zoo, thiab hauv av. Kev sib raug zoo, lub ntsaws ntawm lub load yuav tsum muaj peb tus pins sib haum rau sab fais fab mov, kom cov khoom siv hluav taws xob tuaj yeem ua kom raug.
Nco ntsoov tias muaj peb yam uas yuav tsum tau ua:
Thawj yog tias cov duab, qhov loj me, txoj kab uas hla, thiab qhov ntev ntawm cov pins ntawm lub ntsaws thiab lub qhov (socket) yuav tsum sib haum ib los ntawm ib qho, txwv tsis pub, kev ua haujlwm ntsaws tsis tuaj yeem ua tiav. Cov ntsiab lus no qhia txog lub cev qauv thiab pinout ntawm lub plug ua ke.
Qhov thib ob yog tias qhov tso zis hluav taws xob tus nqi ntawm cov khoom siv hluav taws xob yuav tsum ua kom tau raws li qhov xav tau ntawm tus nqi thauj khoom, txwv tsis pub, cov kev cai ntawm cov hluav taws xob tsis tuaj yeem ua tiav. Qhov no txiav txim siab qib specification ntawm lub plug ua ke.
Qhov thib peb yog tias qhov tso zis impedance ntawm lub zog hluav taws xob yuav tsum sib haum rau cov khoom siv impedance ntawm lub load, txwv tsis pub, lub hwj huam zoo tsis tuaj yeem ua tiav. Qhov no txiav txim siab qhov ua haujlwm ntawm cov khoom siv hluav taws xob.
Peb lub ntsiab lus no yog qhov tseeb qhov kev pom zoo ntawm lub cev theem ntawm lub hwj chim ntsaws ua ke.
Saib ntawm kev sib txuas lus interface dua. Hauv ISO / OSI qauv ntawm kev sib pauv ntaub ntawv hauv computer, txheej txheej ntawm lub cev yog txheej qis tshaj (txheej 1). Nws qhia meej meej cov duab ntawm lub interface, lub ntsiab lus ntawm lub interface pins, theem interface thiab hom byte.
Cov hom byte ntawm no yog hais txog pes tsawg cov ntaub ntawv hauv ib byte, pes tsawg tus pib bits/stop bits, thiab pes tsawg parity khoom. Feem ntau, ib byte muaj 8 cov ntaub ntawv khoom, 1 pib me ntsis (nres me ntsis), thiab 1 parity ntsis.
Cia peb saib ntawm kev ua haujlwm ntawm kev sib txuas lus interface thiab kev sib txuas lus network.
Thaum peb dai lub xov tooj nrog peb lub xov tooj ntawm tes, peb pom tias ob tog tuaj yeem teb qhov hu thaum tham, uas yog hu ua ob txoj haujlwm ua haujlwm. Yog tias koj mloog tsis tau thaum hais lus, thiab hais tsis tau thaum teb, tab sis ob tog muaj peev xwm hais tau thiab mloog, uas yog, hom kev hais lus walkie-talkie, qhov no yog hu ua semi-ob-txoj kev ua haujlwm. .
