SGPAT10xx-100 User Guide
33515 Rev. A
http://www.transition.com/
LPT and RFD function
The LPT (Link Pass-through) allows the media converter to monitor both the fiber
and copper RX ports for loss of signal. In case of a loss of RX signal on one media
port, the converter will automatically disable the TX signal to the other media port,
thus passing through the link fault. RFD (Remote Fault Detect) lets the converter
stop sending link pulse to the link partner once a loss of the fiber RX signal is
encountered. Then the link partner will synchronously stop sending data. FEF
prevents loss of valuable data transmitted over invalid link. Combining LPT and FEF
troubleshooting features of SGPAT10xx-100, both end devices can be notified of a
loss of fiber link.
When link fault pass through function is enabled, link status on TX port will inform
the FX port of the same device and vice versa. From the link fault pass through
procedure illustrates in the figure below, if link fail happens on TX port (1), the local
FX port sends non-idle pattern to notice the remote FX port (2). The remote FX port
then forces its TX port to link failed after receiving the non-idle pattern (4). In other
words, this mechanism will alert the link fault status of local TX port to the remote
converter’s TX port, and the link status of the remote TX port will become off. Link
status LED will also be off for both SGPAT10xx-100 and its link partner.
PoE Technology
Power over Ethernet
or
PoE
technology describes a system to transfer electrical
power, along with data, to remote devices over standard twisted-pair cable in an
Ethernet network. This technology is useful for powering IP telephones, wireless
LAN access points, network cameras, remote network switches, embedded
computers, and other appliances where it would be inconvenient, expensive (mains
wiring must often be done by qualified and/or licensed electricians for legal or
insurance reasons) or infeasible to supply power separately. It doesn't require
modification of existing Ethernet cabling infrastructure.
IEEE 802.3af
(Power over Ethernet), the specification allows the powering device to
use a voltage between 44–57 VDC, though the nominal voltage is 48V, over two of
the four available pairs on a Cat.3/Cat.5e cable with a selectable current of 10–350
mA subject to a maximum load power of 15.40W. Only about 12.95W are available
after counting cable losses, and most switched power supplies will lose another 10–
25% of the available power.
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