Cov neeg koom nrog hauv kev tswj xyuas kev lag luam paub tias ob qho tib si kev tsim khoom thiab kev lag luam kev vam meej vam khom PLC automation tswj. Kev hais lus dav dav, PLC tuaj yeem nkag siab tias yog qhov txuas ntxiv ntawm cov khoom siv hluav taws xob hauv nruab nrab. Hauv kev siv cov khoom tsim tawm, PLCs txo qis cov nqi tswj kev lag luam thaum txhim kho cov khoom siv hauv nruab nrab thiab kev tswj tsis siv neeg. Txhawm rau ua tus tswv PLC programming, lub hauv paus ruaj khov hauv PLC cov txheej txheem yog qhov tseem ceeb.
PLC (Programmable Logic Controller) yog lub khoos phis tawj tswj tau dav siv hauv kev lag luam automation, neeg hlau, txheej txheem tswj, thiab cov cuab yeej zoo sib xws. Hauv qab no yog cov ntsiab lus tseem ceeb rau PLC programming beginners:
1. Basic Principles of Logic Gates:Kev ua haujlwm tseem ceeb tshaj plaws hauv PLC tswj yog kev ua haujlwm zoo, suav nrog THIAB, LOSSIS, TSIS, thiab XOR. Mastering lub hauv paus ntawm logic rooj vag yog qhov yuav tsum tau ua ua ntej rau PLC programming. Kev nkag siab txog cov cim sawv cev ntawm cov rooj vag logic thiab qhov tseeb cov lus cim kuj tseem ceeb.
2. Ladder Diagram Programming Basics:Ladder diagram yog hom lus siv feem ntau siv rau PLCs. Nws lub tswv yim tseem ceeb suav nrog kev tso cov neeg ua haujlwm logic raws txoj kab ntsug los tsim ib lossis ntau tus qauv ntaiv, yog li tsim cov logic tswj.
3. Module thiab Chaw Nyob Concepts:PLCs feem ntau muaj ntau lub modules (xws li, input modules, output modules, intermediate modules). Nkag siab txog cov haujlwm tseem ceeb thiab cov yam ntxwv ntawm txhua qhov module yog qhov tseem ceeb. Tsis tas li ntawd, txhua qhov module muaj qhov chaw nyob sab nraud thiab qhov chaw tso tawm, yuav tsum tau paub txog qhov chaw nyob sawv cev thiab lawv lub ntsiab lus.
4. Timer thiab Counter Siv:Timers thiab cov txee yog nquag siv hauv PLC programming los tswj cov khoom siv sij hawm thiab lub voj voog suav. Nkag siab txog hom timers thiab counters, lawv cov ntawv thov scenarios, thiab programming txoj kev yog qhov tseem ceeb.
5. Kev hloov ntaub ntawv thiab kev ua haujlwm:PLC programming feem ntau suav nrog kev hloov pauv cov ntaub ntawv thiab kev ua haujlwm, xws li hexadecimal - mus rau - decimal conversion, bitwise operations, thiab byte operations. Lub hauv paus ruaj khov hauv kev hloov pauv cov ntaub ntawv thiab kev ua haujlwm yog ib qho tseem ceeb ntawm PLC programming proficiency.
Nkag siab txog PLC Cov Cai Ua Haujlwm
PLCs ua haujlwm siv txoj hauv kev "sequential scanning, nruam looping". Thaum lub sijhawm ua haujlwm, CPU ib ntus scans qhov program khaws cia hauv cov neeg siv lub cim xeeb raws li cov lus qhia ua ntu zus. Yog tias tsis muaj cov lus qhia dhia, nws ua rau cov neeg siv cov kev pab cuam ua ntu zus los ntawm thawj cov lus qhia txog kev ua tiav. Nws mam li rov qab mus rau qhov kev qhia thawj zaug kom pib lub voj voog scanning tshiab. Thaum lub sij hawm txhua lub voj voog scan, PLC kuj ua cov haujlwm xws li kev ntsuas cov tswv yim tawm tswv yim thiab ua kom cov zis tawm tshiab.
Lub voj voog ntawm PLC scan yuav tsum muaj peb theem: input sampling, program execution, and output refresh. Thaum lub sij hawm input sampling theem: PLC sequentially scans thiab nyeem lub on/off xwm txheej los yog input cov ntaub ntawv los ntawm tag nrho cov input terminals ib ntus muab cia rau hauv lub input latches. Cov ntaub ntawv no yog tom qab ntawd sau rau hauv cov ntaub ntawv nkag mus rau hauv cov xwm txheej, yog li rov ua kom cov khoom nkag. Nws ces kaw cov input ports thiab nkag mus rau qhov kev pab cuam execution theem. Thaum lub sij hawm tso zis refresh theem: Thaum tag nrho cov lus qhia raug ua tiav, lub xeev rau / tawm ntawm cov ntaub ntawv tso tawm cov xwm txheej raug xa mus rau qhov tso zis latches thaum lub sijhawm no. Cov xeev no yog tom qab tso tawm los ntawm cov txheej txheem tshwj xeeb (relays, transistors, lossis thyristors) los tsav cov khoom siv sib txuas.
Hauv cov ntsiab lus, PLC lub hauv paus kev paub txog kev ua haujlwm suav nrog cov ntsiab lus ntawm lub rooj vag logic, ladder diagram fundamentals, module thiab chaw nyob sawv cev, timer thiab counter siv, kev hloov ntaub ntawv, thiab kev ua lej lej. Kev paub txog cov hauv paus no yog qhov tseem ceeb rau PLC programming, ua kom muaj kev nce qib hauv cov kev txawj ntse kom ua tiav kev tswj hwm kev lag luam zoo dua.