1 Mawu Oyamba
PoE imatchedwanso Power over LAN (PoL) kapena Active Ethernet, yomwe nthawi zina imatchedwa Power over Ethernet mwachidule.Izi ndizomwe zaposachedwa kwambiri zomwe zimagwiritsa ntchito zingwe zotumizira za Efaneti zomwe zilipo kuti zitumize deta ndi mphamvu nthawi imodzi, ndikusunga kugwirizana ndi machitidwe ndi ogwiritsa ntchito a Ethernet.Muyezo wa IEEE 802.3af ndi mulingo watsopano wozikidwa pa POE ya Power-over-Ethernet system.Imawonjezeranso milingo yofananira yoperekera mphamvu mwachindunji kudzera pazingwe zama netiweki pamaziko a IEEE 802.3.Ndiwowonjezera muyeso wa Ethernet womwe ulipo komanso mulingo woyamba wapadziko lonse lapansi wogawa mphamvu.muyezo.
IEEE idayamba kupanga mulingo mu 1999, ndipo mavenda oyambilira omwe adatenga nawo gawo anali 3Com, Intel, PowerDsine, Nortel, Mitel, ndi National Semiconductor.Komabe, kusowa kwa muyezo uwu kwakhala kukulepheretsa kukula kwa msika.Mpaka June 2003, IEEE idavomereza muyezo wa 802.3af, womwe udafotokoza momveka bwino zinthu zowunikira ndi kuwongolera mphamvu m'makina akutali, ndi ma routers olumikizidwa, masiwichi, ndi ma hubs ku mafoni a IP, machitidwe otetezera, ndi ma network amderalo opanda zingwe kudzera pa zingwe za Efaneti.Njira yoperekera mphamvu ya mfundo ndi zida zina imayendetsedwa.Kukula kwa IEEE 802.3af kumaphatikizapo kuyesetsa kwa akatswiri ambiri amakampani, zomwe zimalolanso kuti muyezowo uyesedwe mokwanira.
Mphamvu yofananira pa Ethernet system.Ikani zida zosinthira za Efaneti mu chipinda cholumikizira mawaya, ndipo gwiritsani ntchito kanyumba kapakati katali ndi kagawo kamagetsi kuti mupereke mphamvu ku LAN yopotoka.Kumapeto kwa awiri opotoka, magetsi amagwiritsidwa ntchito popangira mafoni, malo opanda zingwe, makamera, ndi zipangizo zina.Pofuna kupewa kuzima kwa magetsi, UPS ingagwiritsidwe ntchito.
2 mfundo
Chingwe chokhazikika cha Gulu 5 chili ndi ma awiri awiri opotoka, koma awiri okha omwe amagwiritsidwa ntchito mu l0M BASE-T ndi 100M BASE-T.IEEE80 2.3af amalola ntchito ziwiri.Pini yopanda ntchito ikagwiritsidwa ntchito popereka mphamvu, zikhomo 4 ndi 5 zimalumikizidwa ngati mlongoti wabwino, ndipo zikhomo 7 ndi 8 zimalumikizidwa ngati mlongoti woyipa.
Pamene pini ya deta ikugwiritsidwa ntchito popangira magetsi, magetsi a DC amawonjezeredwa pakatikati pa transmission transformer, zomwe sizimakhudza kutumiza deta.Mwanjira iyi, awiri 1, 2 ndi awiri 3, 6 akhoza kukhala ndi polarity iliyonse.
Muyezowu sulola kugwiritsa ntchito zinthu ziwirizi panthawi imodzi.Zida zamagetsi za PSE zimatha kugwiritsa ntchito kumodzi kokha, koma zida zogwiritsira ntchito mphamvu za PD ziyenera kusinthika kuzochitika zonse ziwiri nthawi imodzi.Muyezo umanena kuti magetsi nthawi zambiri amakhala 48V, 13W.Ndizosavuta kuti zida za PD zipereke 48V kutembenuka kwamagetsi otsika, koma nthawi yomweyo ziyenera kukhala ndi voteji yachitetezo cha 1500V.
3 magawo
Dongosolo lathunthu la POE limaphatikizapo magawo awiri: zida zamagetsi (PSE) ndi zida zamagetsi (PD).Chipangizo cha PSE ndi chipangizo chomwe chimapereka mphamvu ku chipangizo cha kasitomala wa Ethernet, komanso ndi woyang'anira njira yonse yamagetsi ya POE Ethernet.Chipangizo cha PD ndi katundu wa PSE yemwe amavomereza mphamvu, ndiko kuti, chipangizo cha kasitomala cha dongosolo la POE, monga mafoni a IP, makamera otetezera maukonde, ma APs, ndi zipangizo zina zambiri za Ethernet, monga PDAs kapena ma charger a foni (kwenikweni, mwachitsanzo, ndi zipangizo zina za Ethernet). mphamvu iliyonse sichidutsa 13W Chipangizocho chikhoza kupeza mphamvu yofananira kuchokera kuzitsulo za RJ45).Awiriwa amachokera ku IEEE 802.3af muyezo ndikukhazikitsa kugwirizana kudzera pa PD kugwirizana, mtundu wa chipangizo, mlingo wogwiritsira ntchito mphamvu ndi zina za chipangizo cholandira mphamvu, ndipo pamaziko awa, PD imayendetsedwa ndi PSE kudzera pa Ethernet.
Magawo akuluakulu amagetsi amtundu wamagetsi a POE ndi awa:
1. Mpweyawu uli pakati pa 44V ndi 57V, ndi mtengo wake wa 48V.
2. Zomwe zimaloledwa panopa ndi 550mA, ndipo zoyambira pakali pano ndi 500mA.
3. Zomwe zimagwira ntchito pano ndi 10-350mA, ndipo kudziwika kwachulukira ndi 350-500mA.
4. Pansi pazikhalidwe zopanda katundu, kuchuluka komwe kumafunikira ndi 5mA.
5. Perekani magawo atatu a mphamvu zamagetsi zofunikira za 3.84～12.95W pazida za PD, kuchuluka kwake sikudutsa 13W.(Dziwani kuti milingo ya PD 0 ndi 4 sikuwonetsedwa ndipo sayenera kugwiritsidwa ntchito.)
4 ntchito ndondomeko
Mukakonza zida zopangira magetsi a PSE pamaneti, njira yogwirira ntchito ya POE Power pa Ethernet ikuwonetsedwa pansipa.
1. Kuzindikira
Pachiyambi, chipangizo cha PSE chimatulutsa mpweya wochepa kwambiri pa doko mpaka utazindikira kuti kugwirizana kwa chingwe cha chingwe ndi chipangizo cholandira mphamvu chomwe chimathandizira IEEE 802.3af muyezo.
2. Gulu la chipangizo cha PD
Pamene PD ya chipangizo chakumapeto cholandira chizindikirika, chipangizo cha PSE chikhoza kuyika chipangizo cha PD ndikuyesa kutaya mphamvu kwa chipangizo cha PD.
Panthawi yoyambira ya nthawi yosinthika (nthawi zambiri zosakwana 15μs), chipangizo cha PSE chimayamba kupereka mphamvu ku chipangizo cha PD kuchokera pamagetsi otsika mpaka chimapereka mphamvu ya 48V DC.
4. Mphamvu zamagetsi
Amapereka mphamvu yokhazikika komanso yodalirika ya 48V DC ya zida za PD kuti ikwaniritse kugwiritsa ntchito mphamvu kwa zida za PD zomwe sizidutsa 15.4W.
5. Kuzimitsa
Ngati chipangizo cha PD chikuchotsedwa pa intaneti, PSE idzafulumira (kawirikawiri mkati mwa 300-400ms) imasiya kugwiritsira ntchito chipangizo cha PD, ndikubwerezanso njira yodziwira kuti muwone ngati chingwe cha chingwe chikugwirizana ndi chipangizo cha PD.
5 njira yopangira magetsi
Muyezo wa PoE umatanthawuza njira ziwiri zogwiritsira ntchito zingwe zotumizira za Efaneti kutumiza mphamvu ya DC ku zida zogwirizana ndi POE:
1.Mid-Span
Gwiritsani ntchito mawaya omwe sanagwiritsidwe ntchito mu chingwe cha Efaneti kutumiza mphamvu ya DC.Amagwiritsidwa ntchito pakati pa masiwichi wamba ndi zida zolumikizira maukonde.Itha kupereka mphamvu ku zida zolumikizira maukonde kudzera pa chingwe cha netiweki.Midspan PSE (zida zamagetsi zapakatikati) ndi zida zapadera zowongolera mphamvu, zomwe nthawi zambiri zimayikidwa pamodzi ndi chosinthira.Ili ndi ma jacks awiri a RJ45 ofanana ndi doko lililonse, imodzi imalumikizidwa ndi chosinthira ndi chingwe chachifupi, ndipo chinacho chimalumikizidwa ndi chipangizo chakutali.
Mapeto-Spani
Kuwongolera kwachindunji kumaperekedwa nthawi imodzi pawaya wapakati womwe umagwiritsidwa ntchito potumiza deta, ndipo kutumiza kwake kumagwiritsa ntchito ma frequency osiyana ndi chizindikiro cha data cha Ethernet.Endpoint PSE yofananira (zida zopangira magetsi) ili ndi chosinthira cha Ethernet, rauta, hub kapena zida zina zosinthira maukonde zomwe zimathandizira ntchito ya POE.Zikuwonekeratu kuti End-Span idzakwezedwa mwachangu.Izi zili choncho chifukwa deta ya Efaneti ndi kufalitsa mphamvu kumagwiritsa ntchito awiri awiri, zomwe zimathetsa kufunika kokhazikitsa mzere wodzipatulira wodziyimira pawokha.Izi ndi zingwe zoyambira 8 zokha komanso muyezo wofananira wa RJ- Soketi ya 45 ndiyofunikira kwambiri.
6 chitukuko
PowerDsine, wopanga zida zamphamvu pa-Ethernet chip, azichita msonkhano wa IEEE kuti apereke mwalamulo mulingo wa "high-power-over-Ethernet", womwe umathandizira magetsi a laputopu ndi zida zina.PowerDsine ipereka pepala loyera, kutanthauza kuti 802.3af standard 48v kulowetsa ndi 13w kupezeka kwa mphamvu ziyenera kuwirikiza kawiri.Kuphatikiza pa makompyuta apakompyuta, mulingo watsopanowu uthanso mphamvu zowonetsera zamadzimadzi ndi mafoni amakanema.Pa Okutobala 30, 2009, IEEE idatulutsa mulingo watsopano kwambiri wa 802.3at, womwe umanena kuti POE ikhoza kupereka mphamvu zapamwamba, zomwe zimaposa 13W ndipo zimatha kufikira 30W!