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Back view: LPD105A
4/16/2010
#26592
Technically Speaking
Power over Ethernet (PoE).
The seemingly universal network connection, twisted-pair
Ethernet cable, has another role to play, providing electrical power
to low-wattage electrical devices. Power over Ethernet (PoE)
was ratified by the Institute of Electrical and Electronic Engineers
(IEEE) in June 2000 as the 802.3af-2003 standard. It defines the
specifications for low-level power delivery—roughly 13 watts at
48 VDC—over twisted-pair Ethernet cable to PoE-enabled devices
such as IP telephones, wireless access points, Web cameras, and
Place silo photo here (on last page).
audio speakers.
Up to 3 photos - all on this page
The way it works is simple: Ethernet cable that meets CAT5
LPD100A
If 4 photos - 2 on this page, two on prior page.
(or better) standards consists of four twisted pairs of cable,
If 5 or more, 3 on last page and then work back.
and PoE sends power over these pairs to PoE-enabled devices.
In one method, two wire pairs are used to transmit data,
and the remaining two pairs are used for power. In the other
method, power and data are sent over the same pair.
When the same pair is used for both power and data,
the power and data transmissions don't interfere with each other.
Because electricity and data function at opposite ends of the
frequency spectrum, they can travel over the same cable.
LPD101A
TYPICAL APPLICATIONS
• Use one set of twisted-pair wires for both data and power.
• Save money by eliminating the need to run electrical wiring.
• Quickly set up a temporary workgroup.
• If your LAN is protected from power failure by a UPS, the PoE PD
Switches connected to your LAN are also protected from power
failure.
• Use the switch increase the range of your copper network by
enabling you to add up to another 100 meters of UTP cabling.
Standards — IEEE 802.3x, IEEE 802.3u, IEEE 802.3af
CE Approval — Yes
Environmental — Operating temperature: +32 to +122° F (0 to +50° C);
Storage temperature: -13 to +158° F (-25 to +70° C);
Humidity: 5% to 90% noncondensing
Power — Inline PoE Power injector
Size — 1.6"H x 4.8"W x 7.3"D (4.1 x 12.2 x 18.5 cm)
Weight — 1.8 lb. (0.8 kg)
724-746-5500
blackbox.com
T E c h S P E c S
Electricity has a low frequency of 60 Hz or less, and data transmis-
sions have frequencies that can range from 10 million to 100
million Hz.
There are two types of devices involved in PoE configura tions:
Power Sourcing Equipment (PSE) and Powered Devices (PD).
PSEs, which include end-span and mid-span devices, provide
power to PDs over the Ethernet cable. An end-span device is often
a PoE-enabled network switch that's designed to supply power
directly to the cable from each port. The setup would look some-
thing like this:
A mid-span device is inserted between a non-PoE device and
the network, and it supplies power from that juncture. Here is a
rough schematic of that setup:
Power injectors, a third type of PSE, supply power to a specific
point on the network while the other network segments remain
without power.
PDs are devices like switches, surveillance cameras, sensors,
wireless access points, and any other devices that operate on PoE.
Item
PoE PD Switches
(5) 10/100BASE-T
(4) 10/100BASE-T plus (1) SFP Slot
(3) 10/100BASE-T plus
(1) 100BASE-SX, Multimode, 850-nm
300 m, ST
®
300 m, SC
(3) 10/100BASE-T plus (1) 100BASE-SX, Multimode, 1300-nm
2 km, ST
2 km, SC
(3) 10/100BASE-T plus (1) 100BASE-SX, Single-Mode 1310-nm
40 km, ST
40 km, SC
80 km, ST
80 km, SC
100 km, SC
(3) 10/100BASE-T plus
(1) Single-Strand 100BASE-FX, Single-Mode
20 km, SC (Order one of each.)
1310-nm TX/1550-nm RX
1550-nm TX/1310-nm RX
40 km, SC (Order one of each.)
1310-nm TX/1550-nm RX
1550-nm TX/1310-nm RX
60 km, SC (Order one of each.)
1310-nm TX/1550-nm RX
1550-nm TX/1310-nm RX
BLACK BOX
Code
LPD100A
LPD101A
LPD102A
LPD103A
LPD104A
LPD105A
LPD106A
LPD107A
LPD108A
LPD109A
LPD110A
LPD111A
LPD112A
LPD113A
LPD114A
LPD115A
LPD116A
3 of 3
®
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