Firikwensin matsin lamba 89448-34020 don sassan mota na Toyota

1. Sadarwa ta nesa

A halin yanzu (4 zuwa 20 mA) shine mafi kyawun haɗin analog ɗin da aka fi so lokacin watsa bayanai akan nesa mai nisa. Wannan shi ne saboda fitowar wutar lantarki ya fi sauƙi ga kutsewar amo, kuma siginar kanta za a rage ta da juriya na kebul. Koyaya, fitarwa na yanzu na iya jure nisa mai nisa kuma yana ba da cikakken ingantaccen karatun matsa lamba daga mai watsawa zuwa tsarin sayan bayanai.

2. Ƙarfi zuwa tsangwama RF

Layukan kebul suna da rauni ga tsangwama na lantarki (EMI)/ mitar rediyo (RFI)/ electrostatic (ESD) daga igiyoyi da layukan da ke kusa. Wannan hayaniyar lantarki da ba dole ba zata haifar da mummunar lalacewa ga manyan sigina masu ƙarfi kamar siginar lantarki. Ana iya shawo kan wannan matsala cikin sauƙi ta hanyar amfani da ƙananan impedance da manyan sigina na yanzu, kamar 4-20 mA.

3, gyara matsala

Siginar 4-20mA tana da fitowar 4 mA kuma ƙimar matsa lamba sifili ne. Wannan da gaske yana nufin cewa siginar tana da "sifili mai rai", don haka ko da karatun matsa lamba sifili ne, zai cinye 4 mA na yanzu. Idan siginar ya faɗi zuwa 0 mA, wannan aikin zai iya ba mai amfani da alamar kuskuren karantawa ko asarar sigina. Ba za a iya samun wannan ba a yanayin siginar wutar lantarki, wanda yawanci ke tashi daga 0-5 V ko 0-10 V, inda fitarwar 0 V ke nuna matsa lamba.

4. Keɓewar sigina

Siginar fitarwa na 4-20 mA ƙananan sigina ne na halin yanzu, kuma ƙaddamarwa a ƙarshen biyu (watsawa da karɓa) na iya haifar da madauki na ƙasa, yana haifar da sigina mara kyau. Don guje wa wannan, kowane layin firikwensin 4-20mA yakamata a ware shi da kyau. Koyaya, idan aka kwatanta da fitarwar 0-10 V, wannan baya hana firikwensin zama daisy-chained zuwa kayan aikin USB guda ɗaya.

5. Karbar daidaito

Lokacin watsawa daga firikwensin matsa lamba, voltmeter na iya fassara siginar 0-10 V cikin sauƙi a ƙarshen karɓa. Don fitowar 4-20 mA, ana iya karanta siginar kawai bayan an canza mai karɓa zuwa ƙarfin lantarki. Domin maida wannan sigina zuwa digowar wutar lantarki, ana haɗa resistor a jere a tashar fitarwa. Daidaiton wannan resistor yana da matukar mahimmanci don auna daidaiton siginar da aka karɓa.