U khathetse ke ho lahleheloa ke khetho ea PLC? Latela melao-motheo ena e 8 e sebetsang ho etsa khetho e nepahetseng!
U khathetse ke ho lahleheloa ke khetho ea PLC? Latela melao-motheo ena e 8 e sebetsang ho etsa khetho e nepahetseng!
U khathetse ke ho lahleheloa ke khetho ea PLC? Latela melao-motheo ena e 8 e sebetsang ho etsa khetho e nepahetseng!
Pele u khetha PLC, mohato oa pele ke ho hlalosa litlhoko tsa sistimi. Ha sena se se se hlakile, o ka khetha moetsi le mohlala. Empa u etsa liqeto tsee joang? Sengoliloeng sena se fana ka tataiso e qaqileng ho u thusa ho khetha PLC e lumellanang hantle le litlhoko tsa hau, e koahelang bahlahisi, mehlala, lintlha tsa I/O, le mesebetsi ea taolo.
1. Baetsi ba PLC
Ha ho khethoa moetsi oa PLC, lintlha tsa bohlokoa joalo ka litlhoko tsa mosebelisi, ho tloaelana ha moqapi ka mefuta e fapaneng, ho lumellana ha lihlahisoa tse tšehetsang, le ts'ehetso ea ts'ebeletso ea tekheniki li lokela ho nahanoa. Ka kakaretso, lihlahisoa tse tsoang lik'hamphani tse kholo tsa machaba li tšepahala. Bakeng sa lisebelisoa tse nyane, tse ikemetseng kapa litsamaiso tse bonolo tsa taolo, li-PLC tsa Japane hangata li fana ka boleng bo betere. Bakeng sa litsamaiso tse kholo tse nang le litlhoko tse phahameng tsa marang-rang le likhokahano, li-PLC tsa indasteri tse tsoang Europe le U.S. li atisa ho ba molemo haholo ka lebaka la bokhoni ba tsona bo phahameng ba puisano.
Bakeng sa liindasteri tse khethehileng tse kang metallurgy kapa koae, ho bohlokoa ho khetha litsamaiso tsa PLC tse nang le ts'ebetso e netefalitsoeng le rekoto e tšepahalang ea likarolo tseo.
2. Lintlha tsa Input / Output (I/O).
Palo ea lintlha tsa I/O ke paramente ea mantlha ea PLC. Ho fumana lintlha tse hlokahalang tsa I/O, bala palo eohle ea lintlha tsa I/O tse hlokahalang bakeng sa lisebelisoa tsa hau tsa taolo. Ka tloaelo, o lokela ho kenyelletsa moeli oa 10% ho isa ho 20% bakeng sa scalability. Ha o odara, liphetoho le tsona li lokela ho etsoa ho ipapisitsoe le litšobotsi tsa sehlahisoa sa moetsi oa PLC.
3. Bokhoni ba ho boloka
Bokhoni ba polokelo ba PLC bo bolela likarolo tsa polokelo ea lisebelisoa tseo e fanang ka tsona. Bokhoni ba lenaneo, polokelo e hlileng e sebelisoang bakeng sa lits'ebetso tsa basebelisi, e nyane ho feta palo eohle ea polokelo. Kaha matla a lenaneo ha a tsejoe nakong ea moralo (pele ho ngoloa lenaneo la kopo ea mosebedisi), ho hakanngoa ho latela bokhoni ba polokelo. Mokhoa o tloaelehileng oa khakanyo ke: (palo ea lintlha tsa I/O tsa dijithale × 10–15) + (palo ea lintlha tsa analoge I/O × 100) = mantsoe a felletseng (likotoana tse 16 ka lentsoe), ka karolo e eketsehileng ea 25%.
4. Mesebetsi ea ho laola
Ha u khetha PLC, nahana ka litšobotsi tse latelang tsa bohlokoa: mesebetsi ea computational, mesebetsi ea taolo, bokhoni ba puisano, likarolo tsa lenaneo, lisebelisoa tsa ho hlahloba, le lebelo la ho sebetsa.
Mesebetsi ea Computational
Li-PLC tsa mantlha hangata li ts'ehetsa ts'ebetso e utloahalang, nako le ho bala. Li-PLC tsa mahareng li boetse li kenyelletsa phetoho ea data le ts'ebetso ea papiso. Mesebetsi e tsoetseng pele ea khomphutha joalo ka ts'ebetso ea algebra le phetiso ea data e tloaelehile ho li-PLC tse kholo. Li-PLC tsa maemo a holimo li bile li tšehetsa ts'ebetso ea PID bakeng sa taolo ea analog le lipalo tse ling tse tsoetseng pele. Ho ipapisitse le ts'ebeliso, maemo a mangata a hloka feela ts'ebetso ea logic le nako / ho bala, ha phetiso ea data le papiso e ka hlokahala ho tse ling.
Laola Mesebetsi
Mesebetsi ea taolo e kenyelletsa taolo ea PID, matšeliso a phepelo, taolo ea karo-karolelano, joalo-joalo PLCs e sebelisoa haholo-holo bakeng sa taolo ea logic e latellanang. Maemong a mangata, balaoli ba le bang kapa ba li-loop tse ngata ba sebetsana le mesebetsi ea ho laola analog. Bakeng sa mesebetsi e rarahaneng ea ho laola, li-module tse bohlale tsa ho kenya / ho tsoa (mohlala, li-unit tsa PID kapa li-counter-speed counters) li ka ntlafatsa lebelo la ho sebetsa le ho boloka mohopolo.
Mesebetsi ea Puisano
Litsamaiso tsa PLC tse bohareng ho isa ho tse kholo li lokela ho ts'ehetsa li-fieldbus tse ngata le li-protocol tse tloaelehileng tsa puisano (mohlala, TCP/IP) 'me li lokela ho khona ho hokela marang-rang a tsamaiso ea feme ha ho hlokahala. Likhokahano tsa puisano li lokela ho kenyelletsa likou tsa serial/parallel, Ethernet ea indasteri, joalo-joalo Bakeng sa ho hloka chelete le ho tšepahala, libese tsa puisano li lokela ho lumellana le maemo a machaba le ho finyella litlhoko tsa sebaka.
Mesebetsi ea mananeo
Lenaneo la PLCmming e ka etsoa kantle ho naha (CPU e arolelanoang lipakeng tsa PLC le programmer) kapa inthaneteng (li-CPU tse arohaneng tsa PLC le programmer). Lipuo tse hlano tse tloaelehileng tsa lenaneo ke Chate ea Sequential Function (SFC), Ladder Diagram (LD), Function Block Diagram (FBD), Instruction List (IL), le Structured Text (ST). Ka nepo, PLC e tlameha ho ts'ehetsa lipuo tse ling joalo ka C kapa Basic bakeng sa lits'ebetso tse ikhethileng.
Mesebetsi ea Tlhahlobo
Litlhahlobo tsa PLC li koahela lisebelisoa le software ka bobeli. Litlhahlobo tsa Hardware li khetholla liphoso ka licheke tse utloahalang, ha tlhahlobo ea software e kenyelletsa licheke tsa kahare (tse amanang le ts'ebetso) le kantle (tse amanang le puisano). Bokhoni bo matla ba ho hlahloba bo fokotsa nako ea tlhokomelo le litlhoko tsa tekheniki bakeng sa basebelisi.
Ho sebetsa Lebelo
Lebelo la ho sebetsa la PLC le ama ts'ebetso ea nako ea nnete. Haeba nako ea lets'oao e le khuts'oane ho feta potoloho ea skena ea PLC, lets'oao le kanna la hloloheloa. Lebelo la ho sebetsa le ipapisitse le lintlha tse kang bolelele ba lenaneo le bokhoni ba CPU. Li-PLC tsa sejoale-joale li sebetsana le litaelo tsa binary ka li-microseconds tse 0.2-0.4, tse fihlelang litlhoko tsa taolo ea lebelo le holimo. Linako tsa potoloho ea ho skena e lokela ho ba ≤0.5ms/K bakeng sa li-PLC tse nyane le ≤0.2ms/K bakeng sa litsamaiso tse kholoanyane.
5. Mefuta ea PLC
Li-PLC li arotsoe ka mefuta e kopaneng le ea modular. Li-PLC tse kopantsoeng li na le lintlha tse fokolang le tse tsitsitseng tsa I / O, tse etsang hore li tšoanelehe bakeng sa lisebelisoa tse nyenyane tsa taolo (mohlala, Siemens S7-200, Mitsubishi FX series). Li-PLC tsa Modular li fana ka litlhophiso tse feto-fetohang tsa I/O ka li-module tse feto-fetohang 'me li loketse litsamaiso tse kholoanyane (mohlala, Siemens S7-300/S7-400, Mitsubishi Q series).
6. Khetho ea Mojule
Digital I/O Modules
Li-module tsa Digital I / O li fapana ka litlhaloso (mohlala, lihlahisoa tsa relay, lihlahisoa tsa transistor) le lintlha tsa I / O (lintlha tse 8, 16, 32). Lihlahisoa tsa li-relay li na le chelete e ngata empa li na le nako e khutšoanyane ea bophelo, ha lihlahisoa tsa thyristor li potlakile empa li theko e boima haholo. Khetho e lokela ho lumellana le litlhoko tsa kopo.
Li-module tsa Analog I/O
Li-module tsa ho kenya li-analog li sebetsana le matšoao a kang 4-20mA hona joale kapa 0-10V voltage. Li-module tsa analog li fana ka matšoao a hona joale kapa a voltage. Li-module li fapana ka lipalo tsa likanale (likanale tse 2, 4, 8) 'me li lokela ho khethoa ho latela litlhoko tse itseng.
Li-module tsa mosebetsi
Li-module tsa ts'ebetso li kenyelletsa puisano, boemo, tlhahiso ea pulse, ho bala ka lebelo le phahameng, taolo ea PID, le li-module tsa taolo ea mocheso. Ha u khetha, nahana ka bobeli ba hardware le software.
7. Mesebetsi ea ho Hlokahala
Bakeng sa lits'ebetso tse mahlonoko, ho fokotsoa ho ka sebelisoa bakeng sa likarolo tsa taolo (mohlala, 1B1 redundancy bakeng sa CPU le phepelo ea motlakase) le li-interfaces tsa I / O. Litlhophiso tse sa hlokahaleng li ntlafatsa ts'epahalo ea sistimi.
8. Melao e Akaretsang
Hang ha mofuta oa PLC le litlhaloso li hlalositsoe ka ho pharaletseng, fumana lintlha tsa motheo le litekanyetso tsa karolo ka 'ngoe ho latela litlhoko tsa taolo. Ha u khetha li-module, beha pele:
- Katleho ea moruo: Ho leka-lekanya litekanyetso tsa ts'ebetso ea litšenyehelo, katoloso, le boiketlo ba ts'ebetso.
- Tšebeliso e bonolo: Nolofatsa moralo le ho fokotsa likarolo tsa taolo ea kantle.
- Standardization: Sebelisa li-module tse tšoanang ho nolofatsa theko le tlhokomelo.
- Tšebelisano: Netefatsa hore likarolo tsohle lia lumellana, ho tsoa ho moetsi a le mong.