以前本人也(ye)很疑惑，到(dao)底怎么實現供電的(de)？后來才知道，這要歸功于PoE交換機內部的(de)PoE芯片。

      PoE交(jiao)換(huan)(huan)機之所(suo)以(yi)稱為供(gong)(gong)電(dian)(dian)(dian)交(jiao)換(huan)(huan)機，是因為其內部多了PoE模塊和(he)芯(xin)片，可以(yi)控制(zhi)(zhi)是否(fou)供(gong)(gong)電(dian)(dian)(dian)。這(zhe)種網(wang)線供(gong)(gong)電(dian)(dian)(dian)技術(shu)可以(yi)將電(dian)(dian)(dian)力信(xin)號通過網(wang)線傳輸，而不是像傳統那樣只(zhi)能通過電(dian)(dian)(dian)線傳輸。當PoE交(jiao)換(huan)(huan)機和(he)攝像頭(tou)連接后(hou)，PoE控制(zhi)(zhi)芯(xin)片會檢測(ce)所(suo)連接的這(zhe)個(ge)設(she)備是否(fou)支持(chi)PoE供(gong)(gong)電(dian)(dian)(dian)，檢測(ce)結果是的話那么就(jiu)決定供(gong)(gong)電(dian)(dian)(dian)，接下(xia)來就(jiu)繼續對(dui)它(ta)所(suo)需的電(dian)(dian)(dian)力進(jin)行(xing)分類(lei)，來最終決定提供(gong)(gong)多少(shao)的電(dian)(dian)(dian)力供(gong)(gong)應(ying)。

      比如攝像頭供(gong)電(dian)(dian)是8W，那(nei)么(me)PoE交換(huan)機就提供(gong)8W相(xiang)對的電(dian)(dian)力，如果是15W那(nei)么(me)就提供(gong)15W的電(dian)(dian)力供(gong)應。

      需要說明的在檢測(ce)環節，如果檢測(ce)出攝(she)(she)(she)像頭(tou)不(bu)(bu)支持PoE供電(dian)，那(nei)么該PoE交(jiao)(jiao)換機(ji)就(jiu)(jiu)不(bu)(bu)供電(dian)了，也(ye)(ye)就(jiu)(jiu)是攝(she)(she)(she)像機(ji)也(ye)(ye)不(bu)(bu)能(neng)正常工作。換句話說，決定PoE交(jiao)(jiao)換機(ji)能(neng)否為攝(she)(she)(she)像頭(tou)供電(dian)的就(jiu)(jiu)是內部的PoE芯片(pian)，這(zhe)也(ye)(ye)是它和(he)普通交(jiao)(jiao)換機(ji)最大的區別。