以太網供電適應更高的要求

　　作為一個足智多謀的物種，工程師們花了很長時間才意識到，在安全設備等遠程設備上運行兩組電纜——一個用于通信，另一組用于供電——既昂貴又單調。幸運的是，5類電纜（及以上）用于以太網網絡可以承載一些幾十瓦很長的電纜，它是完美的做工作。因此以太網上的電源概念誕生了。

　　本文概述了POE及其優點，并介紹了PoE +，這項技術的發展使布線能夠承載更高的負載。然后文章從主要供應商中尋找專門的部件，以簡化建立POE系統的工作。

　　The advantages of PoE

　　Perhaps the biggest benefit of PoE is its simplicity. Once it is installed for communication， standard Ethernet cable can be used for power as well. That saves on materials， labor， installation time， and ongoing maintenance costs. There is a need for PoE-compliant switches and power supplies， of course， but a range of vendors offer ready-to-fit products that are simple to install.

　　The centralized and flexible nature of PoE eliminates the need for each powered device on the network to have its own local power supply. That allows the devices to be placed anywhere and easily relocated later if required.