Ngaba udiniwe kukulahleka kukhetho lwe-PLC? Landela le migaqo isi-8 ukwenza ukhetho olufanelekileyo!
Ngaba udiniwe kukulahleka kukhetho lwe-PLC? Landela le migaqo isi-8 ukwenza ukhetho olufanelekileyo!
Ngaba udiniwe kukulahleka kukhetho lwe-PLC? Landela le migaqo isi-8 ukwenza ukhetho olufanelekileyo!
Ngaphambi kokukhetha i-PLC, inyathelo lokuqala kukuchaza iimfuno zenkqubo. Xa oku kucacile, unokukhetha umenzi kunye nemodeli. Kodwa uzenza njani ezi zigqibo? Eli nqaku libonelela ngesikhokelo esicacileyo sokukunceda ukhethe i-PLC efanelekileyo kakhulu kwiimfuno zakho, ukugubungela abavelisi, iimodeli, amanqaku e-I / O, kunye nemisebenzi yokulawula.
1. Abavelisi be-PLC
Xa umisela umenzi we-PLC, izinto eziphambili ezifana neemfuno zomsebenzisi, ukuqhelana komyili kunye neempawu ezahlukeneyo, ukuhambelana kweemveliso ezixhasayo, kunye nenkxaso yenkonzo yobugcisa kufuneka ithathelwe ingqalelo. Ngokubanzi, iimveliso ezivela kwiinkampani ezinkulu zamazwe ngamazwe zithembekile. Kwizixhobo ezincinci, ezizimeleyo okanye iinkqubo zokulawula ezilula, ii-PLC zaseJapan zihlala zibonelela ngexabiso elingcono. Kwiinkqubo ezinkulu ezineemfuno zothungelwano eziphezulu kunye neemfuneko zonxibelelwano, ii-PLC zoshishino ezivela eYurophu nase-US zithande ukuba luncedo ngakumbi ngenxa yobuchule bazo obuphezulu bonxibelelwano.
Kumashishini akhethekileyo afana nesinyithi okanye icuba, kuyacetyiswa ukuba ukhethe iinkqubo ze-PLC ezinobungqina bokusebenza kunye nerekhodi ethembekileyo kula macandelo.
2. Igalelo/Imveliso (I/O) Amanqaku
Inani lamanqaku e-I/O yiparameter esisiseko ye-PLC. Ukumisela amanqaku e-I / O afunekayo, bala inani elipheleleyo lamanqaku e-I / O afunekayo kwisixhobo sakho sokulawula. Ngokuqhelekileyo, kufuneka ubandakanye i-10% ukuya kwi-20% ye-margin ye-scalability. Xa uodola, uhlengahlengiso kufuneka kwakhona lwenziwe ngokusekelwe kwiimpawu zemveliso ye-PLC yomenzi.
3. Umthamo wokuGcina
Umthamo wokugcina we-PLC ubhekiselele kwiiyunithi zokugcina zehardware ezibonelela ngazo. Umthamo weprogram, ugcino olusetyenziswa ngokwenene kwizicelo zabasebenzisi, luncinci kunomthamo opheleleyo wokugcina. Ekubeni amandla eprogram awaziwa ngexesha lesigaba soyilo (ngaphambi kokuba inkqubo yesicelo somsebenzisi ibhalwe), kuqikelelwa ngokusekelwe kumthamo wokugcina. Ifomula yoqikelelo oluqhelekileyo yile: (inani lamanqaku e-digital I/O × 10–15) + (inani lamanqaku e-analog I/O × 100) = amagama apheleleyo (i-16 bits ngegama), kunye ne-25% eyongezelelweyo yomda.
4. Imisebenzi yokulawula
Xa ukhetha i-PLC, qwalasela ezi mpawu zilandelayo eziphambili: imisebenzi yokubala, imisebenzi yokulawula, amandla okunxibelelana, iimpawu zeprogram, izixhobo zokuxilonga, kunye nesantya sokucubungula.
Imisebenzi yokubala
Ii-PLC ezisisiseko zihlala zixhasa ukusebenza okunengqiqo, ixesha, nokubala. Ii-PLC zoluhlu oluphakathi zikwabandakanya ukutshintshwa kwedatha kunye nokusebenza kokuthelekisa. Imisebenzi yokubala ephucukileyo efana nokusebenza kwealgebra kunye nokuhanjiswa kwedatha kuxhaphakile kwiiPLC ezinkulu. Ii-PLC ezikumgangatho ophezulu zide zixhase imisebenzi ye-PID yolawulo lwe-analog kunye nezinye izibalo eziphambili. Ngokuxhomekeke kwisicelo, ezininzi iimeko zifuna kuphela ingqiqo kunye nexesha / ukubala imisebenzi, ngelixa ukuhanjiswa kwedatha kunye nokuthelekisa kunokufuneka kwabanye.
Control Functions
Imisebenzi yokulawula ibandakanya ulawulo lwe-PID, imbuyekezo ye-feedforward, ulawulo lomlinganiselo, njl. njl. Ii-PLC zisetyenziswa ikakhulu kulawulo olulandelelanayo lwengqiqo. Kwiimeko ezininzi, abalawuli abangatshatanga okanye abane-loop ezininzi baphatha imisebenzi yokulawula i-analog. Kwimisebenzi yokulawula enzima, iimodyuli ezihlakaniphileyo / iimodyuli zemveliso (umzekelo, iiyunithi ze-PID okanye i-high-speed counters) zinokuphucula isantya sokucubungula kunye nokugcina imemori.
Imisebenzi yoNxibelelwano
Iinkqubo ze-PLC eziphakathi ukuya kwezinkulu kufuneka zixhase iibhasi ezininzi kunye neeprothokholi zonxibelelwano ezisemgangathweni (umzekelo, i-TCP / IP) kwaye kufuneka zikwazi ukuxhuma kwiinethiwekhi zolawulo lwefektri xa kuyimfuneko. Unxibelelwano lwezonxibelelwano kufuneka lubandakanye i-serial / parallel port, i-Ethernet yemboni, njl. Ukunciphisa umsebenzi kunye nokuthembeka, iibhasi zonxibelelwano kufuneka zihambelane nemigangatho yamazwe ngamazwe kwaye zihlangabezane neemfuno zomgama.
Imisebenzi yeNkqubo
Inkqubo ye-PLCi-mming ingenziwa ngaphandle kweintanethi (i-CPU ekwabelwana ngayo phakathi kwe-PLC kunye nomdwelisi weprogram) okanye kwi-intanethi (ii-CPU ezihlukeneyo ze-PLC kunye nomdwelisi weprogram). Iilwimi ezintlanu zokucwangcisa ezisemgangathweni ziTshati yokuSequential Function (SFC), iLadder Diagram (LD), iFunction Block Diagram (FBD), uLuhlu lweMiyalelo (IL), kunye neSibhalo esiMiselweyo (ST). Ngokunqwenelekayo, i-PLC kufuneka kwakhona ixhase iilwimi ezongezelelweyo ezifana no-C okanye iSiseko kusetyenziso olukhethekileyo.
Uxilongo lweMisebenzi
Uxilongo lwe-PLC lugubungela zombini izixhobo kunye nesoftware. Ukuxilongwa kwe-Hardware kuchonga iziphene ngokutshekisha okunengqiqo, ngelixa ukuxilongwa kwesoftware kubandakanya kwangaphakathi (okunxulumene nokusebenza) kunye nokuhlolwa kwangaphandle (okunxulumene nonxibelelwano). Amandla okuxilonga anamandla anciphisa ixesha lokugcina kunye neemfuno zobugcisa kubaqhubi.
Isantya sokusebenza
Isantya sokucubungula i-PLC sichaphazela ukusebenza kwexesha lokwenyani. Ukuba ixesha lomqondiso lifutshane kunomjikelezo wokuskena we-PLC, umqondiso unokuphoswa. Isantya sokuqhubekeka sixhomekeke kwizinto ezifana nobude beprogram kunye nezakhono ze-CPU. Ii-PLC zanamhlanje zibamba imiyalelo yokubini kwi-microseconds eyi-0.2–0.4, ihlangabezana neemfuno zolawulo olukwisantya esiphezulu. Amaxesha omjikelezo wokuskena kufuneka abe ngu-≤0.5ms/K kwii-PLC ezincinci kunye ne-≤0.2ms/K kwiinkqubo ezinkulu.
5. Iintlobo ze-PLC
Ii-PLC zihlelwe ngokweendidi ezidibeneyo kunye neemodyuli. Ii-PLC ezidityanisiweyo zinamanqaku e-I / O anqunyelwe kwaye asisigxina, okwenza ukuba afaneleke kwiinkqubo ezincinci zokulawula (umzekelo, i-Siemens S7-200, i-Mitsubishi FX series). Ii-PLC zeModyuli zibonelela ngolungelelwaniso lwe-I/O oluguquguqukayo ngeemodyuli eziguquguqukayo kwaye zilungele iinkqubo ezinkulu (umzekelo, Siemens S7-300/S7-400, Mitsubishi Q series).
6. Ukukhetha iModyuli
Iimodyuli zeDigital I/O
Iimodyuli ze-Digital I / O ziyahlukahluka kwiinkcukacha (umzekelo, iziphumo zokubuyisela, iziphumo ze-transistor) kunye namanqaku e-I / O (8, 16, 32 points). Iziphumo zokudluliselwa zingabizi kakhulu kodwa zinexesha elifutshane lokuphila, ngelixa iziphumo ze-thyristor zikhawuleza kodwa zibiza kakhulu. Ukhetho kufuneka luhambelane neemfuno zesicelo.
Iimodyuli ze-Analog I/O
Iimodyuli ze-analog zegalelo zibamba iimpawu ezifana ne-4-20mA yangoku okanye i-0-10V yombane. Iimodyuli zemveliso ye-analog ngokufanayo zibonelela ngemiqondiso yangoku okanye yombane. Iimodyuli ziyahluka kwinani letshaneli (2, 4, 8 channels) kwaye kufuneka zikhethwe ngokusekelwe kwiimfuno ezithile.
IiModyuli zoMsebenzi
Iimodyuli zomsebenzi zibandakanya unxibelelwano, ukubeka, ukuphuma kwe-pulse, ukubala ngesantya esiphezulu, ulawulo lwe-PID, kunye neemodyuli zokulawula ukushisa. Xa ukhetha, qwalasela zombini ihardware kunye nesoftware ehambelanayo.
7. Imisebenzi yokuNgafuneki
Ukusetyenziswa okubalulekileyo, ukuchithwa kwemisebenzi kungaphunyezwa kwiiyunithi zokulawula (umzekelo, i-1B1 yokuphindaphinda i-CPU kunye nokunikezelwa kwamandla) kunye ne-interfaces ye-I / O. Ulungelelwaniso olungafunekiyo luphucula ukuthembeka kwenkqubo.
8. Imigaqo Jikelele
Emva kokuba uhlobo lwe-PLC kunye neenkcukacha zichazwe ngokubanzi, misela iinkcukacha ezisisiseko kunye neeparitha zecandelo ngalinye ngokusekelwe kwiimfuno zolawulo. Xa ukhetha iimodyuli, beka phambili:
- Ukusebenza kakuhle kwezoqoqosho: Ulungelelwaniso lweendleko zokusebenza, ukwandiswa, kunye nokusebenza ngokulula.
- Ukusetyenziswa ngokulula: Yenza lula ukuyila kunye nokunciphisa izinto zolawulo lwangaphandle.
- Umgangatho: Sebenzisa iimodyuli ezifanayo ukwenza lula ukuthenga nokugcina.
- Ukuhambelana: Qinisekisa ukuba onke amacandelo ayahambelana, ukusuka kumenzi ofanayo.