I-4-20mA Signal Ingadluliswa Kude Kangakanani?

Isignali engu-4-20mA Ingadluliswa Kude Kangakanani?

Lokhu akulula kakhulu ukunikeza impendulo umbuzo, uma uma ezinye izici ezithonya zonke zinganakwa, singalinganisa

esimweni esijwayelekile, ingahamba cishe ngama-200-500m. Sazini imininingwane eyisisekelo mayelana ne-4-20mA.

1. Iyini i-4-20mA Signal?

Isiginali ye-4-20mA iyiphrothokholi ejwayelekile esetshenziswa ezimbonini eziningi. Kuyindlela yokudlulisa idatha yesignali ye-analogi kuluphu yamanje enezintambo ezimbili, ehlinzeka ngendlela ethembekile yokuxhumana phakathi kwamadivayisi. Amanani asuka ku-4-20mA ngokuvamile amelela u-0 kuya ku-100% webanga lokulinganisa.

2. Izinzuzo ze-4-20mA Signals

Kungani izimboni zithanda ukusebenzisa amasiginali we-4-20mA? Kokukodwa, abangenwa kalula nomsindo uma kuqhathaniswa namasignali kagesi. Lokhu kuvumela ukudluliswa kwamabanga amade ngaphandle kokuphazamisa ubuqotho besignali. Ngaphezu kwalokho, "uziro obukhoma" ku-4mA uvumela ukutholwa kwamaphutha.

3. Idluliselwa kanjani Isignali engu-4-20mA?

Isignali engu-4-20mA idluliswa ngeluphu yamanje enezintambo ezimbili lapho ucingo olulodwa luyi-voltage yokuhlinzeka kanti enye iyindlela yokubuyela emthonjeni. Ukushintshashintsha kwamanje ngaphakathi kweluphu kumelela idatha yesiginali.

4. Kodwa yiba nezinto ezithile okufanele uzicabangele:

Into ephazanyisiwe:

①I-Excitation Voltage;

②I-Voltage Minimum Operating Voltage Evunyelwe I-Transmitter;

③Usayizi we-resistor ethatha i-voltage esetshenziswa idivayisi yebhodi ukuqoqa okwamanje;

④Usayizi wokumelana nocingo.

Ingakwazi ukubala kalula ibanga lokudluliswa kwethiyori le-4-20mA yesiginali yamanje.

Ngalezi zibalo ezine ezihlobene. Phakathi kwazo, i-Uo yi-voltage yokuhlinzeka yesidluliseli,

futhi kufanele kuqinisekiswe ukuthi i-Uo ≥ Umin igcwele ngokugcwele (yamanje I=20mA). Okungukuthi: Sebenzisa-I.(RL+2r)≥ Umin.

Ngokuvamile idinga ukukala amanani ahlukahlukene angewona kagesi njengezinga lokushisa, ingcindezi,

isilinganiso, i-engeli njalonjalo ezimbonini. Zonke zidinga ukuguqulwa zibe i-analoguekagesi

isignali edlulisela kusilawuli noma idivayisi yokubonisa eqhele ngamamitha angamakhulu ambalwa. Le divayisi iyaguqula

ubuningi obubonakalayo kusignali kagesi ebizwa ngokuthi isidluliseli. Ukudlulisa ubuningi be-analogue ngo

I-4-20 mA yamanje iyindlela evame kakhulu ezimbonini. Isizathu esisodwa sokwamukela isignali yamanje

ukuthi akulula ukuphazamisa kanye nokumelana okungapheli kwangaphakathi komthombo wamanje.

Ukumelana nocingo ochungechungeni ku-loop akuthinti ukunemba, futhi kungadlulisela amakhulukhulu

wamamitha kumapheya asontekile avamile.

4-20mAkubhekiselwa ku-min current ngokuthi i-4mA, kanti i-max current ingu-20mA. Ngokusekelwe kwimfuneko yokuvikela ukuqhuma,

umkhawulo ngu-20mA. Amandla enhlansi amaningi kakhulu angathungela igesi evuthayo neqhumayo, ngakho-ke i-20mA yamanje ifaneleka kakhulu.

Thola izintambo eziphukile, futhi inani elincane lingu-4mA kune-0mA. Lapho ikhebula lokudlulisela liphukile ngenxa yephutha,

i-loop current yehla iye ku-0. Ngokuvamile sithatha i-2mA njengevelu ye-alamu yokunqanyulwa. Esinye isizathu ukuthi i-4-20mA isebenzisa a

uhlelo lwezintambo ezimbili. Okusho ukuthi, izintambo ezimbili ziyisignali kanye nezintambo zamandla ngesikhathi esisodwa, futhi i-4mA isetshenziselwa ukunikeza ukusebenza kwamanje okumile kwesekethe kunzwa.

Isignali engu-4-20mA Ingadluliswa Kude Kangakanani?

Into ephazanyisiwe:
①Ihlobene ne-voltage evuselelayo;

②Ihlobene ne-voltage encane yokusebenza evunyelwe isidluliseli;

③Kuhlobene nosayizi we-voltage-taking resistor esetshenziswa idivayisi yebhodi ukuqoqa okwamanje;

④Kuhlobene nosayizi wokumelana nentambo.

Ingakwazi ukubala kalula ibanga lokudluliswa kwethiyori le-4-20mA yesiginali yamanje.

Ngalezi zibalo ezine ezihlobene. Phakathi kwazo, i-Uo yi-voltage yokuhlinzeka yesidluliseli,

futhi kufanele kuqinisekiswe ukuthi i-Uo≥Umin igcwele ngokugcwele (i-I=20mA yamanje). Okungukuthi: Sebenzisa-I.(RL+2r)≥Umin.

Ngokwale fomula, ukumelana nocingo okukhulu kungabalwa lapho isidlulisi sisevoltheji ephansi yokusebenza.

I-hypothesis:owaziwa:Ue=24V，I=20mA，RL=250Ω，Umin=12V。Thola inani eliphezulu lika-r njengo-175Ω:

Futhi-ke, ngokusho kwefomula yokubala yokumelana nocingo:

Phakathi kwazo:
ρ——Ukungazweli(Bronze Resistivity=0.017,Aluminium resistivity=0.029)
L——Ubude bekhebula (Iyunithi: M)
S——Umugqa wesiphambano (Iyunithi: Imilimitha yesikwele)
Qaphela: Inani lokumelana lilingana nobude futhi lilinganisa ngokuphambene nendawo yesigaba esiphambene.

Uma ucingo lunde, kukhulu ukumelana; uma ucingo lushubile, luyancipha ukumelana.

Thatha intambo yethusi njengesibonelo, ρ= 0.017 Ω·mm2/m, okungukuthi: ukumelana kwentambo yethusi

enendawo ephambanayo engu-1mm2 nobude obungu-1m ngu-0.017Ω. Bese ubude bentambo ye

175Ω ehambisana no-1mm2 ithi 175/0.017=10294 (m). Ngokombono, ukudluliswa kwesiginali ye-4-20mA

ingafinyelela amashumi ezinkulungwane zamamitha (kuya ngezici ezifana nokuvusa amadlingozi okuhlukile

ama-voltage kanye ne-voltage ephansi yokusebenza ye-transmitter).

I-HENGKO ineminyaka engaphezu kweyi-10 yokuhlangenwe nakho okwenziwe ngokwezifiso kwe-OEM/ODM nobungcweti

ukuklama ngokubambisana/amakhono okuklama okusizwayo. Sihlinzeka ngokukhishwa kwe-4-20mA kanye ne-RS485

inzwa yegesi/i-alamu/module/izinto. Izinga lokushisa elingu-4-20mA kanye ne-RS485 kanye nomswakama

inzwa/i-transmitter/probe nazo ziyatholakala.I-HENGKO iklanyelwe ngokukhethekile amakhasimende ukuba

ukuhlangabezana nezidingo zokulinganisa ezidingekayo zezinqubo zezimboni nokulawulwa kwemvelo.

Kungani i-4 kuya ku-20ma isetshenziselwa Ukudluliselwa Kwesiginali ku-Instrumentation?

Ungahlola njengokulandela ividiyo ukuze wazi imininingwane.

Isiphetho

Isiginali ye-4-20mA iyindinganiso yemboni ngesizathu. Ikhono layo lokudluliselwa amabanga amade ngaphandle kokulahlekelwa ukunemba kuyinzuzo eyinhloko. Yize ingekho impendulo eqondile yokuthi "kude kangakanani" njengoba kuncike kakhulu ezintweni ezifana nokumelana nezintambo, umsindo wesignali, ukunikezwa kwamandla, nokumelana nomthwalo, ngezinyathelo ezifanele ezikhona, ingamboza amabanga amade ngokuthembekile. Ngokusebenzisa kwayo okungokoqobo ezimbonini nobuchwepheshe bezinzwa, sibona ukubaluleka nokubaluleka kwamasignali angu-4-20mA emhlabeni wethu oxhumene.

Imibuzo Evame Ukubuzwa

1. Kuyini ukubaluleka kokuthi "ziro ebukhoma" ku-4mA kusiginali engu-4-20mA?

"Iziro ebukhoma" ku-4mA ivumela ukutholwa kwamaphutha. Uma isignali iwela ngaphansi kuka-4mA, ikhombisa iphutha, njengokunqamuka kweluphu noma ukwehluleka kwedivayisi.

2. Kungani isignali engu-4-20mA ingangenwa kalula nomsindo?

Izimpawu zamanje azithinteki kangako izinguquko zokumelana nomsindo kagesi. Yingakho zincanyelwa ekudluliseleni ibanga elide nasezindaweni ezinomsindo kagesi.

3. Iyiphi indima edlalwa ukumelana nomthwalo ekudluliselweni kwesiginali ye-4-20mA?

Ukumelana nomthwalo kufanele kufane nokunikezwa kwamandla. Uma ukumelana nomthwalo kuphezulu kakhulu, ukunikezwa kwamandla kungase kungakwazi ukushayela iluphu yamanje, okukhawulela ibanga lokudlulisela.

4. Ingabe isignali engu-4-20mA ingadluliselwa ngaphandle kwentambo?

Yebo, ngokusetshenziswa kwama-transmitter nabamukeli abaklanyelwe le njongo ngokuqondile, amasiginali we-4-20mA angadluliselwa ngaphandle kwentambo.

5. Kungenzeka yini ukunweba ibanga lokudlulisela lesiginali ye-4-20mA?

Yebo, ngokusebenzisa izintambo ezifanele, ukunciphisa umsindo, ukuqinisekisa ukutholakala kwamandla okwanele, nokulinganisa ukumelana nomthwalo, ibanga lokudlulisela linganwetshwa.

Uma uhlatshwa umxhwele amandla amasiginali we-4-20mA futhi ufisa ukusebenzisa noma ukwenza kahle lezi zinhlelo embonini yakho,

ungangabazi ukuthatha isinyathelo esilandelayo. Ukuze uthole ulwazi olwengeziwe, usekelo, noma ukubonisana, finyelela kochwepheshe.

Xhumana no-HENGKO manje kuka@hengko.comfuthi masifinyelele amabanga afanele wokudlulisela ndawonye.