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DNP530E_Quick Installation Guide_En_R1
POWER OVER ETHERNET (PoE)
6
Power over Ethernet, also known as PoE, is a
technology for carrying power along with data on
standard CAT5 network cables, allowing devices
to be powered via their network ports. It is sup-
ported by some devices directly (i.g. 802.3af
compliant or “PoE Enabled” devices) while
other devices require PoE accessories, such as
PoE Endspans, PoE Midspans, power injectors
and/or active splitters, in order to make use of the
technology.
Power is injected on the Ethernet Cable Data
Pairs using:
• PoE Endspan – PoE enabled Ethernet switch
• PoE Midspan - PoE multi port injector for use
with non-PoE Ethernet switches
• PoE Injectors – Adapter that injects Power into
an Ethernet cable. Can be used in combination
with an active splitter (for connecting to non-
PoE devices) or used on its own (for connecting
to PoE enabled devices)
• Active Splitter – An adapter that splits the Date
and Power transmissions over a single Ethernet
cable (PoE) into a separate Date (using RJ45
connector) and power stream (using power
barrel connector) for use strictly with non-PoE
devices.
NOTE
that PoE allows devices to be powered
with a power rating of up to 12.9W. Devices that
consume more then 12.9W but less than 39W
require use of High Power PoE (IEEE-802.3at)
devices. High Power PoE devices like the 8000
series from Microsemi are readily available. An
example of an IP camera that would require High
Power PoE to power it up would be PTZ Speed
Dome cameras which consume a lot of power.
A detailed description of the 802.3af standard is
available in IEEE publication SS95312
(http://standards.ieee.org/getieee802/download/
802.3af-2003.pdf).
The main benefits of PoE technology are as
follows:
Lower Costs
• Eliminate the need to run A/C power wires
• Utilize existing IT infrastructure investments
More Flexible
• Locate device where it truly needs to be located
(Not constrained by the location of an AC outlet)
Centralize vs Localize Power Source
• Allow use of a centralized UPS (Uninterruptible
power supply) to guarantee power to the device
even during a power failure
Manageability
• PoE devices that are Simple Network Management
Protocol (SNMP) manageable can be remotely
monitored and controlled
The main benefits of PoE Midspan use over PoE
Endspan use are:
• Improve ROI on current installations
• Minimize capital expenditure
- Keep the existing Switches
• Lower purchase price
- 30% less than Enterprise PoE switch
• Easy and simple to install
- Lower installation costs - 20% less than Enterprise
PoE switch
- Enable higher productivity - Negligible downtime
• PoE investment is protected
- Switch technology changes
- Why pay for PoE every time you upgrade your switch?
• Gain flexibility to power also pre-standard terminals
Examples of PoE installations using…
PoE Endspan
Endspan
IP camera (PoE enabled)
Endspan
Active Splitter
IP Camera (non-PoE)
PoE Midspan
Non-PoE Ethernet Switch
Midspan
IP Camera (PoE
enabled)
Non-PoE Ethernet Switch
Midspan
Active Splitter
IP Camera (non-PoE)
PoE Injector
Non-PoE Ethernet Switch
PoE Injector
IP Camera
(PoE enabled)
Poe In Splitter
Non-PoE Ethernet Switch
PoE Injector
Active Splitter
IP Camera (non-PoE)
Digimerge IP Devices are certified for use with
Microsemi PoE hardware solutions. Visit www.microsemi.
com/PowerDsine for details on all available PoE hardware
solutions.
