LevelOne MIDSPAN POH-0850TX - Manual (Page 3)

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1. Introduction
Power-over-Ethernet (PoE) eliminates the need to run 110/220 VAC power to other
devices on a wired LAN. Using Power-over-Ethernet system installers need to run only
a single CAT5 Ethernet cable that carries both power and data to each device. This
allows greater flexibility in the locating of network devices and significantly decreasing
installation costs in many cases.
There are two system components in PoE -- the Power Sourcing Equipment (PSE)
initiates the connection to the second component, the Powered Device (PD). The
current is transmitted over two of the four twisted pairs of wires in a Category-5 cable.
Power over Ethernet follows the IEEE 802.3af and is completely compatible with
existing Ethernet switches and networked devices. Because the Power Sourcing
Equipment (PSE) tests whether a networked device is PoE-capable, power is never
transmitted unless a Powered Device is at other end of the cable. It also continues to
monitor the channel. If the Powered Device does not draw a minimum current,
because it has been unplugged or physically turned off, the PSE shuts down the power
to that port. Optionally, the standard permits Powered Devices to signal to the PSEs
exactly how much power they need.
Features
POH-0850TX, 8-port power over Ethernet Hub
IEEE802.3af compliance, Power over Ethernet Mid-Spain mode
Remote power feeding up to 100 meters and for IEEE802.3 10Base-T, IEEE
802.3u 100Base-TX standard
Auto detect PD and classification power consumption level
Support manual control port detect and classification
Support system calibrate
Support Auto MDI/MDI-X depends on the uplink switch port.