RS-485 kubatanidza uye masimba

RS-485 mwero kuti yakatanga wokurera ari Electronic Industries Association. To musi, ichi Standard inotaura zvemagetsi zvechadenga ose vagamuchiri uye zvinotakura anoshandiswa dzakasiyana-siyana pakati nepakati digitaalinen gadziriro.

Chii?

Pakati vanamazvikokota RS-485 izita nokururamisira yakakurumbira pakati inowanikwa, iro zvinowanzoshandiswa siyana maindasitiri muitiro kudzora enyika kuti unobva akawanda controllers uyewo zvakasiyana nemamwe mano pakati pavo. Musiyano mukuru pakati inowanikwa wevaduku nevakawanda RS-232 ndechokuti anopa mubatanidzwa panguva pakubhadhara anoverengeka michina.

Kushandisa RS-485 inopiwa mukuru-nokukurumidza kupanana ruzivo pakati siyana mano kuburikidza rimwe-waya kukurukurirana link nehafu-duplex nzira. Vakawanda kushandiswa maindasitiri ano vari nedanho PCS.

The Range uye nokukurumidza

Pachishandiswa vomureza ichi kunokwanisika nhepfenyuro ruzivo dzimwe aimhanya anosvika 10 Mbit / s, apo kufadza zvinoita siyana zvakananga kuvimba pakukurumidza panguva iyo mashoko vari zvitange. Saka, kuti tive nechokwadi kunonyanyisa akurumidze Data hunogona kutapukira haasi kupfuura 120 m, panguva imwe kumhanya 100 kbit / s mashoko kutepfenyura anopfuura 1200 mamita.

Number tichibatanidza mudziyo

Kuwanda namano anogona nokubatanidza RS-485 inowanikwa zvakananga pakuti chii mudziyo unoshandiswa transceivers. Mumwe wokutepfenyurisa akagadzirirwa kuti mawa kuzvidzora 32 pamureza vagamuchiri, asi zvinofanira kunzwisiswa kuti pane vagamuchiri, mazano impedance ndiyo 50%, 25% kana chikamu kunyange diki mureza, uye kana kushandisa michina yakadaro uwandu mano kuchawedzera maererano.

Connectors uye protocols

RS-485 waya haina kwezvipimo chero zvimwe zvinowanika Data mapuranga kana dzakati. Kazhinji zvakanaka kuti humboo kushandiswa uri zvakangofanana mapuranga, iyo inoshandisa RS-232, i.e. humboo matomu, kutanga uye kumisa matomu, uye parity matomu, kana zvichidikanwa.

Kukurukura protocols vanoshanda dzakawanda hurongwa ano rinoitwa pasi "tenzi-nhapwa", kureva, kubva mudziyo pamusoro pemambure yakati ndiye kutungamirira uye anotora kuchitsinhanisa chikumbiro nokutumira kutanga pakati zvose muranda mano zvisingapindirani musoro kero. Zvikuru nevakawanda dzakati kuti nhasi ndiro Modbus RTU.

Zvinokosha kucherechedza kuti RS-485 waya ine vamwe dzakananga mhando connectors kana soldered, kureva, anogona kuitika kiramba connectors, kuti DB9 uye nevamwe.

kubatanidza

Kakawanda, vachishandisa inowanikwa iri rinoita yomunharaunda network, izvo rinobatanidza vakawanda transceivers.

Akatakura kunze RS-485 nokwauri, unofanira nounyanzvi sangana nemumwe chiratidzo nematunhu, inowanzonzi kunzi A uye B. In iyi, kudzorwa hakusi chaityisa zvokuti, anongoti kubata mano hazvishandi.

anobatsira zvahungava hwakaita zvakavimbika

Uchishandisa RS-485 inowanikwa, unofanira kufungawo wandei zvinoitwa basa rake;

• Chinonyanya Zvakanyanya Kunaka Panguva Yepamuviri zvakatipoteredza mureza yedzimudzangara - iri waya pamusoro yakakoswa peya.
• The waya inoguma hazvo vanofanira tisanzwe achibatsirwa specialized inouraya resistors.
• Network, iyo inoshandisa mureza kana USB RS-485, vanofanira kugadzira pasina matavi bhazi topology.
• The mano inofanira kwakabatana kune waya waya sezvo pfupi sezvinobvira.

Panyaya iyi, zvakanaka kugadzirisa kuti kugadzira RS-485 inowanikwa, - a yakakoswa peya, sezvo zvakasiyana zvishoma parasitic chiratidzo nemwaranzi, uye ane dziviriro yakanaka chaizvo kubva kukanganiswa. Kana midziyo kushanda pasi zvikuru yakakwirira zvokunze ruzha, zviri nani kushandisa waya, kudzivirirwa yakakoswa peya, pamwe unodzivirira pasi pamwe waya nenhovo.

chibvumirano

Achishandisa chinouraya resistors vomureza kana USB RS-485 inopa Kufambisa yakazara rakavhurika kuguma waya mutsetse achiteverwa kubvisa zvachose mukana chiratidzo chadzera.

Standard nemishonga resistors akakodzera chakanangana impedance pamusoro waya uye netambo idzo dzinobva yakakoswa-vaviri wire, kazhinji, imwe zvinobetsera ndiye anenge 100-120 ohms. Somuenzaniso, imwe kumbonyanya nevakawanda nhasi UTP-5 waya, iri zvinowanzoshandiswa Ethernet kuisa kwacho ane mashoko maitiro impedance kuti 100 ohms. Nokuti mamwe waya nzira inogona kushandiswa uye mamwe sangano.

Resistors, kana zvichikodzera, inogona chisimbiso panguva waya connector nembambo vatova wokupedzisira mudziyo. Kashoma resistors vari kuiswa iri mudziyo, saka kuti kubatana zviri resistor zvinokosha hwokugadza jumper. Muchiitiko chino, kana maita kure mudziyo zvachose rassoglasovyvaetsya mutsetse. Uye kuti ave nechokwadi dzose kushanda navamwe ezvinhu, unofanira kubatanidza munhu enzanirana chivharo.

chiratidzo mumatunhu

RS-485 anoshandisa nepakati redunhu Data nhepfenyuro, kureva voltage mumatunhu ari chiratidzo mitsetse A uye B achizosiyana vanopikisa.

Kuburikidza Switch zvinofanira inopiwa iri chiratidzo pamwero 1.5 panguva zvizere mutoro, uye hapana anopfuura 6 panyaya kana mudziyo iri idling. The voltage pamwero kunoyerwa differentially hama nomumwe chiratidzo mutsetse.

Where mugamuchiri ndiyo shoma akagamuchira chiratidzo pamwero chero nyaya kunofanira pamwero usina asingasviki 200 MV.

misha

Kana pasina chiratidzo panguva chiratidzo mitsetse, zvishoma zvaizopedza kunoitika, izvo awane mugamuchiri kudzivirira positives venhema.

Nyanzvi vanokurudzira kuita zvaizopedza zvishoma kupfuura 200 MV, sezvo mutengo uyu runoenzanirana unreliability mapazi mureza chiyamuro chiratidzo. Panyaya iyi, kuti A cheni iri kudhonzwa kuti zvakanaka danda riri kupi, nepo cheni B iri kudhonzwa vakaderera.

muenzaniso

Maererano aida misha uye simba romugove voltage kukarukureta rinoitwa masangano resistors. Somuenzaniso, kana zvakakodzera kuwana zvaizopedza pa 250 MV achishandisa chinouraya resistors R _T = 120 ohms kuti kunobva ane voltage 12 V. Sezvo iyi iri resistors vaviri zvakabatana muna zvakafanana nevamwe uye vari zvachose kwete kufunga mutoro kudivi mugamuchiri, kuti kusasarura Kuyerera 0,0042 a, ukuwo zvachose kurwisa zviri kutsvetera redunhu riri 2857 ohms. R _kuona iyi ichava pamusoro 1400 ohms, saka unofanira kusarudza vamwe pedyo sangano.

Muenzaniso aizova 1.5 kohm resistor rinoshandiswa, rakagadzirirwa kuti misha, uyewo zvokunze resistor kusvika 12 volts. Uyezve, munyika yedu ino controller decoupled simba wedzerai goho, inova inokukura nhengo iri chidimbu nengetani.

Chokwadi, pane dzimwe embodiments akawanda kutsvetera kuti kushandisa RS-485 convert nezvimwe zvinhu asi chero zvazvingava, pakutevedzera urongwa kutsvetera nematunhu, zvinokosha kufunga ndechokuti nzvimbo, iyo ichapa izvozvo, vachange nguva nenguva akavhara pasi kana vanopedzisira inogona kubviswa pemambure zvachose.

Kana kuri zvaizopedza, ipapo wedunhu vanokwanisa A ari simbe chose akanaka panyaya redunhu B, izvo zvinoreva pfungwa apo mumwe mudziyo mutsva kwakabatana kuti waya waya pasina Kunyora.

Sizvo wiring uye kusarurama

Kuita pamusoro kurumbidza achibvumira kuti chakaipa kupararira zviratidzo zvemagetsi siyana pfungwa pomumbure iri, kana kushandiswa sehwaro nokuda RS-485 Protocol. Kana isina kuzadziswa mamwe zvinodiwa achamuka kusarurama. Chinonyanya kuoneka kururama dzinotanga kuonekwa panyaya, kana mashoko mwero kunopfuura 1 Mbit / s, asi chaizvoizvo, kunyange panyaya ezasi aimhanya haina varumbidzwa kuteerera mazano aya, kunyange kana nemambure ari "mabasa chete akanaka."

Sei chirongwa?

Panguva mapurogiramu, akasiyana-siyana mafomu anoshanda namano vachishandisa RS-485 mahwanda kana zvimwe Namano inowanikwa ichi, unofanira kufunga zvimwe dzinokosha. Pano vari:

• Usati achatanga kuendesa nyaya, unofanira hazvo Activate yacho wokutepfenyurisa. Pasinei chokwadi kuti, maererano zvimwe zvinyorwa, extradition anogona kutora nzvimbo pakarepo pashure akatendeuka pane vamwe vanamazvikokota vanoti kwokutanga kumbomira, izvo nguva ichava akaenzana mwero pepuranga rimwe. Panyaya iyi, yakarurama negashiro chirongwa nguva kuziva zvakazara zvinopfuura zvikanganiso, uye ubudise normalization nzira yokugadzirira nekutambira date womuchato.
• Mushure wokupedzisira byte kuti mashoko ari wakabudiswa, zviri Dzakamukurudzirawo kuti umbomira usati nokuzviparadzanisa kuti RS-485 mudziyo. Zvikurukuru, izvi imhaka yokuti Serial chiteshi controller kazhinji panguva chipo maviri zvenhoroondo, okutanga chiri akaererana Inlet uye akaronga kuti pakugamuchira data, apo wechipiri kusuduruka goho rinoshandiswa uye nokuda Serial goho. Chero kudimburira hutachiwana controller achiumbwa nyaya chiyamuro remazita kuparadzwa apo mashoko watopiwa inopiwa kune chaishanda mazita, asi haisati yapiwa. It iri chikonzero kuti mushure nhepfenyuro iri hwakakanganiswa, zvakakodzera kuraramisa mumwe kumbomira usati nokuzviparadzanisa ari wokutepfenyurisa, izvo zvinofanira kuva nguva kupfuura anenge 0,5 matomu pane pamatanda. Kuti aite kunyatsoenderana Masvomhu varumbidzwa kuongorora muudzame hwokugadzira mapepa rakashandiswa Serial chiteshi yacho controller.
• Kubvira wokutepfenyurisa, mugamuchiri, uye zvichida, RS-485 convert zvakabatana chete mutsetse, pachake mugamuchiri kuchaita ndinoona sezvo kuchinjwa kuitwa warwo wokutepfenyurisa. It zvinowanzoitika kuti hurongwa hwake asingashumbi kuwana mutsetse, chikamu ichi rinoshandiswa muitiro vachiongorora kuti kwemotokari pakati zvinotakura maviri. In kwakajairika hurongwa kushanda maererano "tenzi-nhapwa", mune kuchinjwa kwacho inokurudzirwa kuti zvakazara kuvhara kudimburira kubva receiver.

Configuration "bhazi" urongwa

inowanikwa iri rinopa mukana tichibatanidza mano kuti kukura "bhazi" apo vose namano uchishandisa rimwe vachipiwa waya. Panyaya iyi, kukurukurirana mutsetse iri compulsorily akabvuma EOL resistors pa mativi.

Kuti vave nechokwadi harmonization hwakagadzwa iyi resistors hwokuratidza nemishonga 620 ohms. Vanogara yakaiswa pamusoro okutanga nookupedzisira mudziyo chokuita mutsetse. Advantageously zvikuru ano mano kuuya mukati enzanirana nemishonga, izvo zvinogona optionally ubatanidzwe mumutsara nokuzvisarudzira jumpers unokosha chiridzwa bhodhi.

Sezvo kukurukura mamiriro pakutanga jumper yakaiswa, zvakakodzera pakutanga kuti avabvise ose namano, ukuwo, kunze okutanga nookupedzisira chokuita mutsetse. The repeater converters muenzaniso S2000-PI mumwe nomumwe goho enzanirana impedance ari kushandisa pedyo chinja, apo namano S2000-COP uye inozivikanwa C2000-K revatema kugumisa impedance, mauri zambuko, zvakafanira kuti kubatana kwayo hakuna kuwanikwa.

Kuti vave nechokwadi refu mutsetse wokukurukurirana, Zvinokurudzirwa kushandisa unyanzvi hwakasiyana repeaters, transponders, akanyatsokodzerwa pamwe zvizere zvaitika-chinja mirayiridzo.

The configuration ane "nyeredzi" urongwa

bazi Chero ari RS-485 mitsetse havasi anodiwa, nokuti iyi pane zvakakwana simba chiratidzo kusarurama, asi kubva inoshanda nemaonero, vanogona kudzivisa vari chiitiko kuti panova kureba pamatavi. Muchiitiko ichi izvozvo hakurevi kugadzwa resistors pamusoro yoga pamatavi.

The RS-485 kuparadzirwa gadziriro, iyo inotongwa kubva panel, uye kana rokupedzisira mudziyo chokuita imwe mutsetse, asi dzichitangira siyana, unofanira chokubatanidza ngetani 0 zvose mano uye kure kuti tibu- inogara potentials dzavo. Kana zvinodiwa izvi zvikasaitwa, ipapo kure kuzvidzora kunogona kuva kusagadzikana riine Namano. Kana waya zvinofanira kushandiswa vanoverengeka yakakoswa waya mbiri, kana ichi yevanoda zvakaenzana redunhu inogona kushandiswa vakasununguka zvachose peya kana zvakakodzera. Pakati pezvimwe zvinhu, uyewo zvinopa mukana uchishandisa kudzivirirwa yakakoswa peya ari chiitiko kuti hapana pasi ndege.

Ndinofanira kufunga?

Advantageously zvikuru ano iyo inopfuura nomunyika waya equipotential, iduku zvakakwana, asi kana 0 V mano kana pachavo manyuko simba chokuita kuti busses vemo vanoverengeka grounding zvinogona musiyano pakati nematunhu akasiyana 0V kungava anokwana zviyero akawanda, uye mune zvimwe zviitiko, kunyange makumi ezviuru volts, apo magetsi ruchiyerera napakati zvinogona equalization redunhu inogona kunyatsonanga rinokosha. Ndicho chikonzero zvinowanzovapo nezvokuti pane kusagadzikana richibatanidza kure uye mudziyo, saka kuti kunyange kukundikana.

Chikonzero ichi kuti unoda kudzivirira kubata pasi redunhu 0 kana panguva dzakawanda, kuti zvakohwewa neketani iyi pane zvimwe vamwe nguva. Unofanirawo kufunga mukana interconnection pakati 0 uye cheni unodzivirira pasi chipo iri midziyo yaishandiswa Ops ino.

Panguva Nzvimbo, ayo kuburikidza zvikuru rinorema remagetsi ezvinhu inozivikanwa, anopa kukwanisa kubatanidza pomumbure wire kuburikidza "zvaitawo kusarurama peya". Muchiitiko chino, zvingava chipo yakaderera muganhu siyana, sezvo capacitance pamusoro waya kwakakwirira.