Poe Overview - 3Com Switch 4800G 24-Port Configuration Manual

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PoE Overview

Introduction to PoE
P E C
O ONFIGURATION
When configuring PoE, go to these sections for information you are interested in:
"PoE Overview" on page 1193
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"PoE Configuration Task List" on page 1194
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"Configuring the PoE Interface" on page 1194
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"Configuring PD Power Management" on page 1196
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"Configuring a Power Alarm Threshold for the PSE" on page 1197
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"Upgrading PSE Processing Software Online" on page 1197
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"Configuring a PD Disconnection Detection Mode" on page 1198
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"Enabling the PSE to Detect Nonstandard PDs" on page 1198
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"Displaying and Maintaining PoE" on page 1199
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"PoE Configuration Example" on page 1199
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"Troubleshooting PoE" on page 1200
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Power over Ethernet (PoE) means that power sourcing equipment (PSE) supplies
power to powered devices (PD) such as IP telephone, wireless LAN access point,
and web camera from Ethernet interfaces through twisted pair cables.
Advantages
Reliable: Power is supplied in a centralized way so that it is very convenient to
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provide a backup power supply.
Easy to connect: A network terminal requires only one Ethernet cable, but no
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external power supply.
Standard: In compliance with IEEE 802.3af, and a globally uniform power
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interface is adopted.
Promising: It can be applied to IP telephones, wireless LAN access points,
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portable chargers, module readers, web cameras, and data collectors.
Composition
A PoE system consists of PoE power, PSE, and PD.
PoE power
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The whole PoE system is powered by the PoE power, which includes external PoE
power and internal PoE power.