Ukuvala Igebe: Ulwazi Lokuxhumana Olubalulekile Lwe-PLC Ochwepheshe Bezogesi

Ukuvala Igebe: Ulwazi Lokuxhumana Olubalulekile Lwe-PLC Kubasebenzi Bakagesi

I-Serial Communication Basics

Ukuxhumana kwe-serial kuyiphrothokholi evamile yedivayisi - ukushintshanisa idatha yedivayisi. Ngokungafani ne-USB, amakhompuyutha amaningi anamachweba amabili e-serial asekelwe ku-RS232. Izimbobo ze-serial nazo zisetshenziswa kabanzi ku-instrumentation nedatha ekude - amadivayisi wokutholwa.

Amapharamitha angukhiye wokuxhumana kwe-serial

Ukuze uthole ukuxhumana okuphumelelayo kwe-serial, amapharamitha alandelayo kufanele afane kuzo zonke izimbobo:

I-Baud Rate: Ikala idatha - isivinini sokudlulisela ngamabhithi ngomzuzwana. Isibonelo, i-baud engu-300 ilingana namabhithi angu-300 ngomzuzwana. Izinga le-baud lithinta ngokuqondile imvamisa yesampula emugqeni wedatha. Amazinga aphezulu e-baud, enza kube lula ukuxhumana kwebanga elifushane, isivinini esikhulu, ahambisana ngokuphambene nebanga lokudlulisela.

Izingcezu zedatha:Bonisa idatha yangempela ekudlulisweni. Amanani ajwayelekile angamabhithi angu-5, 7, noma angu-8. Ngokwesibonelo, i-ASCII evamile isebenzisa amabhithi angu-7, kuyilapho i-ASCII enwetshiwe isebenzisa u-8. Inketho incike kudatha ethile - izidingo zokudlulisela.

Misa amabhithi:Maka isiphetho sephakethe ledatha, ngokuvamile elinamanani angu-1, 1.5, noma amabhithi angu-2. Basiza amadivaysi ukuthi avumelanise amawashi phakathi nokuxhumana. Izitiphu ezengeziwe zikhulisa ukubekezelela iwashi - umehluko wesikhathi kodwa zehlisa idatha - izinga lokudlulisela.

I-Parity Bit:Iphutha elilula - ukuhlola indlela. Izinketho zifaka okulinganayo, okungajwayelekile, okuphezulu, okuphansi, noma akukho. Isilinganiso esilinganayo nesixakile setha i-parity bit ukuze kuqinisekiswe inani elilinganayo noma eliyinqaba lamabhithi aphezulu anengqondo kudatha edlulisiwe. Ukulingana okuphezulu nokuphansi kuvele kusethe kancane kancane kokuphezulu noma phansi okunengqondo, okuvumela amadivayisi atholayo ukuthi athole ukuphazamiseka kokuxhumana okungaba khona noma ukungavumelani.

I-Common PLC Interfaces

RS - 232:Izinga le-RS - 232 livamile ku-IBM - PC kanye nezinhlelo ezihambisanayo. Isekela izinhlelo zokusebenza ezihlukahlukene ezifana nokuxhuma amagundane, amaphrinta, amamodemu, nezinsimbi zezimboni. Ngenkathi i-RS - 232 inika amandla ukuxhumana kwephoyinti - kuya - iphuzu phakathi kwamachweba we-PC serial namadivayisi, ibanga layo eliphezulu lokudlulisela lingamafidi angama-50.

RS - 422:I-RS - 422, esetshenziswa kumakhompyutha we-Apple Macintosh, isebenzisa ukusayina okuhlukile. Ngokungafani ne-RS - 232's single - endground - isiginali ekhonjiwe, ukuhanjiswa okuhlukile kwe-RS - 422 kusebenzisa imigqa emibili yokuthumela nokwamukela amasiginali. Lokhu kuthuthukisa ukungavikeleki komsindo futhi kwandise ibanga lokudlulisela, kuyenze ifanele izilungiselelo zezimboni.

RS - 485:I-RS - 485 ithuthuka ku-RS - 422 ngokusekela amadivayisi afika kwangu-32 kanye nokuchaza izici zikagesi ngobuningi - idivayisi - ukubala izimo zokuqinisekisa ugesi wesignali owanele. Ivumela ukwakhiwa kwamanethiwekhi edivayisi kusetshenziswa imbobo eyodwa ye-RS - 422. Ngomsindo oqinile - ukungavikeleki nokusekelwa kwamadivayisi amaningi, i-RS - 485 ilungele izinhlelo zokusebenza zezimboni ezifana nokwakha amanethiwekhi edivayisi esabalalisiwe axhunywe kuma-PC, izilawuli zokuqoqwa kwedatha, ama-HMI, nezinye izinhlelo zokusebenza. I-RS - 485 iyi-superset ye-RS - 422, evumela ukulawula kwawo wonke amadivayisi we-RS - 422 anamabanga okudlulisela angaphezu kwamamitha angu-4,000.