RS-485 hononga, me te mana

RS-485 Ko te paerewa e i tangohia tuatahi i roto i te Electronic Industries Association. Ki te rā, tenei Paerewa mo ki te āhuatanga hiko o nga mea katoa o farii me foaki whakamahia i roto i te whānuitanga o ngā pūnaha mamati taurite.

He aha te mea te reira?

I roto i ngā tohunga he RS-485 te ingoa tika rongonui o te atanga, Kei te whānui i whakamahia i roto i ngā pūnaha whakahaere tukanga ahumahi mō te tūhono rave rahi pūmana me te he momo o te tahi atu whakaaro i waenganui ia ratou. Ko te rerekētanga matua i waenganui i te atanga o te iti rawa noa RS-232 Ko e whakarato ana te reira mo te uniana i te wa ano o te maha ngā momo o te taputapu.

Mā te RS-485 whakaratohia e te utu nui-tere o ngā mōhiohio i roto i ngā pūrere maha i roto i te hono kōrero kotahi-waea i roto i te aratau hawhe-Matarua. Kei te whānui whakamahia te reira i roto i te ahumahi hou i roto i te tukanga o PCS.

Ko te whānui me te tere

Na roto o tenei paerewa kua tutuki pāpāho mōhiohio ka kīia e ki runga, ki te 10 Mbit / s, i tika ka whakawhirinaki te taea ngā mōrahi i runga i te tere i nei e tuku raraunga. Ko te kupu, ki te whakarite raraunga tere mōrahi e taea te tuku kore te mea neke atu i te 120 m, i i te tere o te 100 kbit / s mōhiohio päpäho te neke atu i te 1200 mita.

Tau pūrere whakakotahi

Ko te maha o ngā pūrere e taea te whakakotahi i te RS-485 atanga ka whakawhirinaki tika i runga i transceivers aha pūrere whakamahia te. Kei te hangaia i ia tuku mo te mana tukutahi 32 e farii paerewa, engari kia matau ai e reira he farii, te parenga ia tāuru ko 50%, 25% ranei tetahi wahi ara iti o te paerewa, me roto i te take o te whakamahi o taua taputapu tau tapeke o ngā pūrere ka nui ake i runga i.

Tūhono me ngā tikanga

e kore te RS-485 taura papa'iraa tetahi etahi papa hōputu raraunga kawa ranei. I roto i te nuinga o te wā pai mō te raraunga whakamahia e rite te taua papa, e whakamahi RS-232, i.e. nga paraire raraunga, te tīmatanga me te mutu paraire, me paraire örite, ki te tika.

mahi kawa kōrero i roto i te nuinga o ngā pūnaha hou e kawea i roto i runga i te "ariki-pononga", e ko, etahi ahua o te pūrere ki runga ki te whatunga ko te tino me riro te tono utu i te tuku i te kaupapa i roto i ngā pūrere pononga katoa rerekē i roto i ngā wāhitau arorau. Ko te kawa tino rongonui mō te tenei ra ko Modbus RTU.

E tano ia tapao e kua hoki nga RS-485 taura etahi momo motuhake o tūhono ranei soldered, e ko, e taea puta tūhono rawhi, te DB9 me etahi atu.

hononga

Nuinga o ngā wā, te whakamahi i tenei atanga tutuki te whatunga rohe, e fakatahai transceivers maha.

A amo i te RS-485 hononga, e hiahia ana koe ki te whakairo ngā ki ia atu arahiko tohu, kōrero nuitia ki rite A me B. I roto i tenei take, e kore te mea pera wehingia te hokinga whakamuri, e kore ngā pūrere hono noa ka mahi.

tīwhiri āwhina

Mā te whakamahi i te atanga RS-485, kia tangohia e koe ki te pūkete e rave rahi ngā āhuatanga o tana mahi:

• Ko te taiao tino tino pai mō te tohu tuku - ko te taura o te rua miro.
• Te taura pito Me tika ki te tinei, i roto i ki te awhina o parenga kāpeka motuhake.
• Whatunga, e whakamahi ana i te paerewa USB ranei RS-485, kia apu kahore tetahi peka o te āhuawhatunga pahi.
• Me hono nga whakaaro ki nga waea taura rite poto rite taea.

I roto i tenei take, ki te otinga pai i roto i te raupapa apu i te atanga RS-485, - he rua miro, rite faikehekehe reira radiation tohu minimally pirinoa, ka kua he tiaki rawa pai i raweketia. Ki te mea ka mahi te taputapu i raro i haruru tino nui waho, he pai ki te whakamahi i te taura, paruruhia rua miro, ngā ki te whenua tiaki ki te whakangungu rakau taura.

whakaaetanga

Na roto o kāpeka parenga paerewa USB ranei RS-485 whakarato oti ruruku o te mutunga tuwhera o te aho taura aru e tino whakakore i te taea o te tohu whakaata.

parenga ātete Paerewa he tika parenga ia āhuatanga o te taura, me aua taura e e hāngai ana i runga i miro-rua taura, i nuinga o te wā, he pai he āhua 100-120 ohms. Hei tauira, he tika rongonui tenei ra UTP-5 taura, kei te whānui e whakamahia ana i roto i te tukanga whakapanga Itarangi kua te parenga ia āhuatanga o 100 ohms. Hoki ētahi atu kōwhiringa taura taea te whakamahi i me tetahi atu haapa'oraa.

Parenga, ki te tika, e taea te hiri i nga titi tūhono taura e kua i roto i te pūrere whakamutunga. Varavara e tāuta parenga i te pūrere, kia ai he tika te hononga o te parenga ki te tāuta i te ou'a. I roto i tenei take, ki te mahi atu i te pūrere rawa raina rassoglasovyvaetsya. A i roto i te tikanga ki te whakarite i te mahi noa o te toenga o te pūnaha, e hiahia ana koe ki te hono i te pōtae ōrite.

taumata tohu

whakamahi RS-485 te pāpāho taiawhio raraunga whārite, e ko, te taumata ngaohiko i runga i te te rārangi tohu me te B ka rerekē i roto i te pato'iraa.

Na roto o te pūoko kia whakaratohia i roto i te taumata tohu o 1.5 i kawenga tonu, me kaua e nui ake 6 i roto i te take, ina te tāhuna i te pūrere. whanganga te taumata ngaohiko te differentially whanaunga ki atu ia raina tohu.

Kei hea te kaiwhiwhi, ko kia te iti riro taumata tohu i roto i tetahi take i te taumata e kore e iti iho i te 200 mV.

displacement

I roto i te take, ka kahore he tohu i nga rārangi tohu, he iti wāhikē puta, e tëtahi te tiaki kaiwhiwhi ki ngā pai teka.

tūtohu tohunga ki te mahi i wāhikē paku nui ake i te 200 mV, mai tenei uara ko te rohe unreliability tohu tāuru paerewa hāngai. I roto i tenei take, unuhia te he mekameka e ki te pou pai o te puna, i unuhia te mekameka B te ki noa.

tauira

I roto i runga ki te displacement e hiahiatia ana me te ngaohiko tatauranga mana supply whakamana te faaroo pūparenga. Hei tauira, ki te he te reira e tika ana ki te whiwhi i te wāhikē i 250 mV te whakamahi i te parenga kāpeka R _T = 120 ohms e te pūtake he ngaohiko o te 12 V. Mai i roto i tenei take e hono te parenga e rua i roto i te whakarara ki tahi i te tahi, me te kore e tango i tino ki pūkete kawenga i runga i te taha kaiwhiwhi, te nāianei rītaha ko 0,0042 he, i te tapeke parenga o te ara iahiko rītaha ko 2857 ohms. R _kite i roto i tenei take, ka waiho e pā ana ki 1400 ohms, na e hiahia ana koe ki te whiriwhiri i etahi haapa'oraa tata.

e kia tētahi tauira 1.5 kohm parenga te whakamahia, hangaia hoki te displacement, me te he iahiko waho ki te 12 volts. I tua atu, i roto i to tatou putanga hakari pūmana pūnaha decoupled mana supply, i te mea he mema peia i roto i te mekameka wāhanga.

O te akoranga, i reira e maha atu taatou o te rītaha e whakamahi RS-485 converter me ētahi atu āhuatanga, engari i roto i tetahi take, te whakatinana i iahiko whakaritenga rītaha, he mea e tika ana ki te tango i ki pūkete te meka e te pae, e ka whakarato i te reira, ia wā kia ka tutakina iho ranei ara mutu ake ka taea te tino nekehia atu te reira i te whatunga.

Ki te reira te Paraire, ka te ara iahiko kaha A i runga i tino mangere he pai ki te faatura ki iahiko B, i te mea he wāhi tohutoro ina te hono i te pūrere hou ki nga waea taura kahore tapanga.

waea hē me te distortion

Mahi i te tūtohutanga i runga taea hoki te tuku noa o tohu hiko i roto i ngā rerekē o te whatunga, ki te whakamahia rite te pūtake mo te kawa RS-485. Ki te kore te rite i te reira i te iti rawa etahi o nga whakaritenga e whakatika distortion. timata nga distortions tino kite ki puta i roto i te take, ki te te auau raraunga he neke atu i te 1 Mbit / s, engari i roto i te meka, ara i roto i te take o terenga raro kore e tūtohu ki te tau'a ore i teie tūtohutanga, ara, ki te ko te whatunga "mahi pai noa."

Me pēhea te ki te hōtaka?

I roto i hōtaka, he momo o ngā tono e mahi ki ngā pūrere te whakamahi i te RS-485 Kairitu atu whakaaro ranei ki tenei atanga, e hiahia ana koe ki te whakaaro te tahi mau ngā nui. Tenei ko ratou:

• I mua ka tīmata koe te tuku i te take, e hiahia ana koe ki te tika whakahohe te tuku. Ahakoa te meka e, kia rite ki etahi puna, kia tango tana pananga wahi tonu i muri i tahuri i runga i, tūtohu etahi tohunga okioki tuatahi, i roto i te wa, ka kia rite ki te tere o tetahi anga. I roto i tenei take, te fariiraa tika o te wa hōtaka ki tino tāutu i ngā hapa rangitahi, ka kawe i māori tukanga ki te faaineine no te te fariiraa raraunga muri.
• I muri tukuna te paita whakamutunga o raraunga e, e tūtohu ana hoki te reira ki te faaea i mua i momotuhia te pūrere RS-485. I roto i ngā, ko tenei e tika ana ki te meka i te pūmana tauranga rangatū maha wā kotahi hakari e rua rēhita, te tuatahi o te mea whakarara ki te kokoru me te tikanga mo te fariiraa i raraunga, i whakamahia te putanga neke tuarua te me mo te putanga rangatū. Tetahi pūmana tuku haukoti i hanga i roto i te take o te rēhita tāuru o te whakangaromanga ina kua whakaratohia te mōhiohio ki te rēhita neke, engari kua kore e ano i whakaputaina. Ko reira hoki tenei take i muri i te mea haukotia te haapurororaa, he mea e tika ana ki te paturu i te tetahi okioki i mua i momotuhia te tuku, kia nei kia te wa nui atu e pā ana ki te 0.5 paraire atu te anga. Hei kawe i tātaitanga atu pau tūtohutia ki tirohia i roto i te taipitopito te tuhinga hangarau e whakamahia ana e te tauranga rangatū o te pūmana.
• Mai te tuku, te kaiwhiwhi, ka pea, kua hono RS-485 pūtahuri ki te raina kotahi, ake te kaiwhiwhi e kite rite te whakawhiti kawea atu e ona ake tuku. Reira i tupu pinepine e i roto i ngā pūnaha āhuatanga e whai wāhi matapōkere ki te aho, whakamahia tenei āhuatanga i roto i te tukanga o te arowhai mō collisions waenganui i rua foaki. I roto i ngā pūnaha tikanga mahi i roto i runga i te "ariki-pononga", tūtohutia i roto i te tukanga whakawhiti e ki tino kati te haukoti i te kaiwhiwhi.

Whirihoranga hōputu "pahi"

whakarato ana tēnei atanga te taea o te whakakotahi whakaaro ki te rahi o "pahi" ka te whakaaro katoa huihuia te whakamahi i te rua kotahi o waea. I roto i tenei take, kei te tuutika whakaae te rārangi kōrero parenga EOL i pito e rua.

Ki te whakarite harmonization whakapumautia i roto i tenei parenga take āhuatanga e ātete 620 ohms. E tāuta tonu ratou i runga i te pūrere tuatahi, me te whakamutunga hono ki te raina. pūrere pai io tino hou hoki hakari roto te ātete ōrite, e taea kōwhiri nei te whakauru i roto i te rārangi mā te te whakatakoto te ou'a i runga i te poari taputapu motuhake.

Mai te āhua tuku te ou'a te tīmatanga tāuta, he mea e tika ana te tīmatanga ki te tango ia ratou i nga whakaaro katoa, aua, ki te kahore hoki te tuatahi, me te whakamutunga hono ki te raina. Ko te tauira pūtahuri repeater S2000-PI mo ia parenga ia putanga ōrite takitahi kē e te pana, i ngā pūrere S2000-COP me te āhuatanga C2000-K ngātahi terminating parenga ia, ai kore he wātea te piriti, e tika ana hoki tona hononga.

I roto i te tikanga ki te whakarite i te raina roa o te kōrero, e tūtohu ana ki te whakamahi i repeaters motuhake, transponders, tuha ki aronga whakaneke tino aunoa.

Ko te whirihoranga o te hōputu "whetu"

Tetahi peka i roto i te rārangi RS-485 kahore e minaminatia, no te mea i roto i tenei take i reira ko te distortion tohu ka makona ratou kaha, engari i te wāhi mahi o te tirohanga, ka taea e ratou te ārai i te kaupapa e reira ko te roa iti o nga manga. I roto i tenei take e kore e rapua e te reira i te tāutanga o parenga i runga i manga motuhake.

Ko te pūnaha tohatoha RS-485, te mana e te i te röpü, me te mea hono i te pūrere whakamutunga ki te raina kotahi, engari kei te whangai i puna rerekē, ka hiahia koe ki te whakakotahi i te mekameka 0 nga whakaaro katoa me te mamao i roto i te tikanga ki te whakarite i te hāngaitanga o ratou moe,. Ki te te kore tutaki tenei titauraa, ka taea whai i te mana mamao he hononga iu ki nga whakaaro. Ki te te taura, ko te ki te whakamahi ki te maha takirua waea miro, i roto i tenei take mo te ara iahiko equalizing pea taea te whakamahi rua tino noa ki te tika. I roto i te tahi atu mea ano, whakarato reira te taea o te whakamahi i te rua miro malu'i i roto i te kaupapa i reira he kore waka rererangi whenua.

Aha e whakaaro ahau?

Pai io te nuinga o nāianei e haere i roto i te equipotential waea, ko reira iti nui, engari i roto i te take 0 V whakaaro ranei ratou e hono puna mana ki te maha o ngā busses rohe Tuhinga rerekētanga pea i waenganui i iahiko rerekē kia 0V maha ngā waeine, a i roto i ētahi wā, ara tekau o volts, i te nāianei e rere i roto i te ara iahiko aifaitoraa pea e taea e tino nui. Ko te take noa o te meka i reira he he hononga iu i waenganui i te mamao me te pūrere, kia kia kia ara ratou kore tenei.

Ko reira hoki take tenei e hiahia ana koe ki te aukati i te taea o te ara iahiko whenua 0 ranei, i te nuinga, ki te hurihia tenei mekameka i etahi tetahi wāhi. Me hoki koe ki te whakaaro i te taea o te ngatahi i waenga i 0 me te mekameka whenua tiaki hakari i roto i te taputapu e whakamahia ana i roto i te pūnaha karere.

I te pae, e kua āhuatanga e te taiao hiko tino taimaha, whakarato te kaha ki te tūhono i te taura whatunga roto i te "rua miro paruruhia". I roto i tenei take, kia ai taua mea hakari raro ngā rohe, mai te mea teitei te āheipuringa o te taura.