Tam sim no, PLC tuaj yeem tau txais cov ntsiab lus thiab sensor cov cim tsis muaj amplifier, yog li dab tsi kev lom zem ntawm "qhov chaw" thiab "ntws"? Tsuas yog cov zis ntawm PLC yuav muaj cov ntsiab lus ntawm "qhov chaw" thiab "xau".

Qhov tseeb, tshwj tsis yog rau Japanese PlC, nws tsis tsim nyog rau lwm plcs los siv cov tsiaj ntawv luv xws li "thiab" ntws ", tab sis PNP thiab NPN tuaj yeem siv ncaj qha.

Pnp yog qhov tsawg-voltage cov kab pej xeem, thiab NPN yog ib txoj kab pej xeem siab. Raws li ntev raws li qhov kev sib txuas no yog qhov tseeb, nws zoo li nws tsis muaj nqi yog tias cov ntsiab lus ntawm "qhov chaw" thiab "ntws" yog thim rov qab. Txawm li cas los xij, lwm lub tswvyim "Logic zoo thiab tsis zoo" kuj yog qhov tsis yog, uas yuav ua rau lub teeb liab ua kom lub teeb liab.

Zoo logic thiab cov laj thawj tsis zoo

Hauv PNP hom kev voj voog, lub davhlau ya nyob twg ntawm cov khoom siv fais fab thiab teeb liab yog nyob rau theem qis ntawm 0V. Thaum cov tswv yim yog nyob rau theem qis, tsis muaj qhov sib txawv sib txawv nrog cov davhlau ya nyob twg, yog li tsis muaj kev hloov teeb liab tso tawm (digital ntau yog 0). Tsuas yog thaum cov tswv yim yog nyob rau theem siab, muaj qhov sib txawv ntawm cov davhlau ya nyob twg thiab nthuav dav hloov teeb liab yog tso zis ntawm qib siab. Qhov kev ntaus nqi digital (digital ntau yog 1) uas yog siv tau thaum lub teeb liab yog nyob rau theem siab yog hu ua PNP zoo logic.

Nyob rau hauv lub npe ntawm NPN, cov davhlau ya nyob twg ntawm lub zog hluav taws xob thiab lub teeb liab yog nyob rau theem siab (tus yam ntxwv ntawm lub suab hluav taws xob siab). Thaum cov tswv yim yog nyob rau theem siab, tsis muaj qhov sib txawv ntawm cov tswv yim thiab cov zis, yog li tsis muaj kev hloov teeb liab tso zis (cov digital ntau yog 0). Tsuas yog thaum lub tswv yim yog nyob rau theem qis (sib sau lub funnel), muaj qhov ua tau zoo (digital hom yog 1) hom kev ua tau zoo yog 1)