Txhim kho cov teeb liab cais rau ntawm PLC tswj txee

Hauv kev lag luam automation, PLC (Programmable Logic Controller) tswj txee ua lub luag haujlwm tseem ceeb, lub luag haujlwm rau kev txais cov cim los ntawm ntau yam sensors thiab actuators, thiab ua tiav kev tswj hwm qhov tseeb ntawm cov txheej txheem ntau lawm los ntawm kev ua haujlwm sab hauv logic. Txawm li cas los xij, hauv kev siv ua haujlwm, PLC tswj txee feem ntau ntsib ntau yam teeb meem electromagnetic nyuaj thiab teeb meem cuam tshuam teeb liab, uas yuav ua rau kev tswj hwm lub kaw lus tsis ua haujlwm, kev ua tsis tiav ntau zaus, thiab txawm tias ua rau muaj kev hem thawj rau cov khoom siv thiab cov neeg ua haujlwm kev nyab xeeb. Yog li ntawd, ntxiv lub teeb liab cais tawmcov ators rau PLC tswj txee tau dhau los ua ib qho kev daws teeb meem.

Cov haujlwm tseem ceeb ntawm cov teeb liab cais suav nrog kev tiv thaiv kev xa cov teeb liab electromagnetic, txo qhov tshwm sim ntawm kev ua tsis tiav ntawm lub cev, thiab muab kev cais tawm thaum muaj cov khoom siv ua tsis tiav ntawm qhov chaw, tiv thaiv kev kis cov teeb meem mus rau tag nrho lub cev tswj hwm. Los ntawm kev hloov pauv thiab hloov cov teeb liab uas PLC tau txais los ntawm cov khoom siv semiconductor, tom qab ntawd cais thiab hloov lawv siv cov khoom siv optical lossis magnetic sensing, thiab thaum kawg demodulating thiab hloov lawv rov qab mus rau lub teeb liab qub lossis cov teeb liab sib txawv, cov txheej txheem no ua kom muaj kev ruaj khov thiab qhov tseeb ntawm lub teeb liab, thaum tseem tiv thaiv kev puas tsuaj rau PLC thiab txo qhov cuam tshuam ntawm cov teeb liab hauv qhov chaw ntawm PLC, tshwj xeeb tshaj yog cov teeb liab clutter. Tsis tas li ntawd, cov teeb liab cais kuj tseem tuaj yeem ua tiav kev hloov pauv teeb liab, xws li hloov cov teeb liab los ntawm PT10 kev sib txuas mus rau hauv 4-20mA teeb liab thiab nkag mus rau hauv PLC systems, zoo zam kev tsis sib haum xeeb ntawm hluav taws xob thiab cov chaw muab hluav taws xob thiab daws qhov teeb meem ntawm kev cuam tshuam ntawm cov voj voog thiab cov khoom siv.

Hauv cov ntawv thov tshwj xeeb, xws li hauv cov kab ntau lawm ntawm lub Hoobkas hlau, kev ntsuas thiab kev tswj hwm tau ua tiav los ntawm PLC, cov cuab yeej automation hauv qhov chaw, thiab cov actuator hauv qhov chaw. PLC raug muab tso rau hauv lub txee tswj hwm uas nyob ntau pua meters ntawm qhov chaw (ua haujlwm ntawm chav sov), thiab cov cuab yeej automation lossis thermocouples los ntawm qhov chaw tso tawm cov teeb liab los ntawm cov xov hlau mus rau hauv lub txee tswj hwm hauv chav tswj hwm. Thaum lub sijhawm no, cov teeb liab nkag mus rau hauv PLC yuav tsum raug cais tawm thiab kuj tseem yuav tsum tau hloov pauv, xws li cais 4-20mA thiab hloov nws mus rau 0-5V ua ntej nkag mus rau PLC. Cov khoom siv uas ua tiav kev cais tawm thiab kev hloov pauv ntawm cov teeb liab thermocouple hu ua "thermocouple signal isolator" lossis "thermocouple temperature transmitter". Nws lub luag haujlwm tseem ceeb suav nrog kev cais cov teeb liab nkag thiab cov teeb liab tso tawm, nrog rau kev hloov cov teeb liab mV theem nkag los ntawm thermocouple mus rau hauv cov teeb liab kev lag luam txheem (4-20mA, 0-5V, 0-10V).

Hauv kev xaus lus, kev teeb tsa cov cuab yeej cais teeb liab yog qhov tseem ceeb heev rau kev txhim kho kev ntseeg tau ntawm cov tshuab ua haujlwm hauv kev lag luam, txo cov nqi ua tsis tiav, tiv thaiv cov khoom siv PLC, thiab txhim kho qhov zoo ntawm cov teeb liab. Nws yog ib qho ntawm cov khoom tseem ceeb los xyuas kom meej tias kev ua haujlwm ruaj khov thiab txhim khu kev qha ntawm cov tshuab tswj hwm.