Kune akati wandei ezvekufambiswa kwemashoko, pfungwa dzakadai se 'kunonoka kuparadzira' uye 'kunonoka skew' dzinounza mupfungwa dzinorwadza dzekirasi yechikoro chepamusoro chefizikisi.Muchokwadi, mhedzisiro yekunonoka uye kunonoka skew pakufambiswa kwechiratidzo inotsanangurwa zviri nyore uye inonzwisiswa.
Kunonoka chivakwa chinozivikanwa kuvepo kune ese marudzi ekutapurirana midhiya.Kunonoka kwekuparadzira kwakaenzana nehuwandu hwenguva inopfuura pakati peinotapurirwa chiratidzo uye kana ichigamuchirwa kune rumwe rutivi rwechannel cabling.Mhedzisiro yacho yakafanana nekunonoka kwenguva pakati pekurova kwemheni uye kutinhira kunonzwika-kunze kwekuti masaini emagetsi anofamba nekukurumidza kupfuura ruzha.Iko chaiyo yekunonoka kukosha kwe twisted-pair cabling ibasa rezita revelocity yekuparadzira (NVP), kureba uye frequency.
NVP inosiyana zvichienderana nemidziyo yemagetsi inoshandiswa mutambo uye inotaridzwa sechikamu chekumhanya kwechiedza.Semuyenzaniso, zvivakwa zvizhinji zvechikamu chechishanu zve polyethylene (FRPE) zvine NVP nhanho kubva pa0.65cto0.70c(apo "c" inomiririra kumhanya kwechiedza ~3 x108 m/s) kana ikayerwa patambo yapera.Teflon (FEP) matambo ekugadzira kubva ku0.69cto0.73c, nepo tambo dzakagadzirwa nePVC dziri mu0.60cto0.64crange.
Hwaro hweNVP hwakaderera huchawedzera kunonoka kwehurefu hwakapihwa hwetambo, sekuwedzera kwekupedzisira-kusvika-kumagumo urefu hwetambo kuchakonzera kuwedzera kwakaenzana mukunonoka-kumagumo.Sezvakangoita mamwe akawanda ekutapurirana paramita, kunonoka kukosha kunotsamira frequency.
Kana akawanda maviri maviri mutambo imwe chete achiratidza kwakasiyana kunonoka kuita, mhedzisiro ndeye kunonoka skew.Kunonoka skew kunotariswa nekuyera mutsauko uripo pakati pevaviri nekunonoka kudiki uye vaviri vane kunonoka kwakanyanya.Zvinhu zvinokanganisa kunonoka kuita skew zvinosanganisira kusarudzwa kwezvinhu, senge conductor insulation, uye dhizaini yemuviri, semisiyano yemitengo yekumonyorora kubva pairi kuenda pairi.
Cable Propagation Kunonoka
Kunyange zvazvo tambo dzese dzakamonyoroka dzichiratidza kunonoka kune imwe nhanho, tambo dzakagadzirwa nehana kuti dzibvumire kusiyana muNVP uye misiyano yehurefu yepeya-peiri ichave nekunonoka kunogamuchirika skew yezvimiro-zvinoenderana zvakachinjika chiteshi magadzirirwo.Humwe hunhu hunogona kukanganisa kunonoka skew kuita zvinosanganisira tambo dzisina kugadzirwa dielectric zvivakwa uye idzo dzine misiyano yakanyanyisa paviri-ku-paviri twist mitengo.
Propagation kunonoka uye kunonoka skew kuita kunotsanangurwa nedzimwe nharaunda nharaunda network (LAN) zviyero zveakaipisisa kesi100 mchannel masisitimu kuti ive nechokwadi chekufambisa kwemasaini.Matambudziko ekutapurirana ane chekuita nekunonoka zvakanyanya uye kunonoka skew anosanganisira kuwedzera jitter uye bit kukanganisa mitengo.Zvichienderana neIEEE 802-yakatevedzana LAN zvirevo, kunonoka kwekuwedzera kwe570 ns/100mat 1 MHz uye yakanyanya kunonoka skew ye45ns/100mup kusvika 100 MHz iri pasi pekutariswa neTIA yechikamu 3, 4 uye 5, 4-matambo tambo.TIA Working Group TR41.8.1 iri kufungawo nezvekuvandudzwa kwezvinodiwa kuti iongorore kunonoka kwekuparadzira uye kunonoka skew ye100 ohm horizontal links uye machanera anovakwa maererano neANSI/TIA/EIA-568-A.Nekuda kwekomiti yeTIA "Letter Ballot" TR-41:94-4 (PN-3772) yakasarudzwa panguva yemusangano waGunyana 1996 kuti ibudise "Industry Ballot" pane yakagadziridzwa gwaro risati raburitswa.Isati yagadziriswa inyaya yekuti mazita echikamu achachinja here kana kuti kwete (semuenzaniso, chikamu 5.1), kuratidza mutsauko pakati petambo dzinoedzwa kuti dziwedzere kunonoka / kunonoka skew zvinodiwa, uye izvo zvisiri.
Kunyangwe kunonoka kuparadzira uye kunonoka skew kuri kugamuchira kutariswa kwakawanda, zvakakosha kuti uzive kuti iyo inonyanya kukosha kabling performance issue kune mazhinji maLAN application inoramba iri attenuation kune crosstalk ratio (ACR).Ipo ACR magidhi anovandudza siginecha kune ruzha reshiyo uye nekudaro kuderedza chiitiko chekukanganisa zvishoma, kuita kwehurongwa hakuna kukanganiswa zvakananga nematanho emakabati ane kunonoka kunonoka skew margins.Semuyenzaniso, 15 ns kunonoka skew yecabling chiteshi kazhinji hazvizokonzerese kuita nani network pane 45 ns, kune system yakagadzirirwa kushivirira kusvika makumi mashanu ns yekunonoka skew.
Nechikonzero ichi, kushandiswa kwetambo dzine kunonoka kunonoka skew margins kwakakosha kune inishuwarenzi yavanopa vachipesana nemaitiro ekuisa kana zvimwe zvinhu zvinogona kusundidzira kunonoka skew pamusoro pemuganho, pane kuvimbisa kuita zvirinani system zvichienzaniswa nechiteshi icho inongosangana nehurongwa hwekunonoka skew miganho neanoseconds akati wandei.
Nemhaka yokuti tambo dzinoshandisa zvakasiyana-siyana dielectric zvinhu zvepairi dzakasiyana zvakawanikwa zvichikonzera matambudziko nekunonoka skew, pave nekukakavadzana kwemazuva ano pamusoro pekushandiswa kwezvinhu zvakasanganiswa dielectric mukugadzirwa kwetambo.Mazwi akaita se“2 by 2” (tambo ine maviri maviri ane dielectric material “A” uye maviri maviri ane material “B”) kana “4 by 0″ (tambo ine mapeya ese mana akagadzirwa kubva kune chero chinhu A, kana B. ) ayo anonyanya kuratidza matanda pane tambo, dzimwe nguva anoshandiswa kutsanangura kuvaka dielectric.
Kunyangwe hype yekutengeserana inogona kutsausa munhu kuti atende kuti zvivakwa chete zvine mhando imwe chete yedhielectric zvinhu zvinoratidzira zvinogamuchirika kunonoka skew kuita, chokwadi ndechekuti tambo dzakagadzirwa nemazvo dzine imwe dielectric material, kana akawanda dielectric zvinhu zvinokwanisa kugutsa kunyange yakanyanya kuomesesa chiteshi kunonoka skew zvinodiwa zvinotsanangurwa nezviyero zvekushandisa uye izvo zviri kutariswa neTIA.
Pasi pemamwe mamiriro, zvivakwa zvakasanganiswa dielectric zvinogona kushandiswa kugadzirisa kunonoka skew misiyano inokonzerwa neakasiyana mareti.Mufananidzo 1 ne2 unoratidza kunonoka kwemumiriri uye skew values zvakawanikwa kubva kune yakasarudzika yakasarudzwa 100 metre cable sample ine "2 by 2" (FRPE/FEP) kuvaka.Ziva kuti kunonoka kwekuparadzira uye kunonoka skew yemuenzaniso uyu 511 ns/100mand 34 ns, zvichiteerana mu frequency renji kubva ku1 MHz kusvika 100 MHz.
Nguva yekutumira: Mar-23-2023