B&B Electronics McBasic TP/FO Operation Manual - page 3
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LinkLoss and Pulsing FiberAlert
LinkLoss and Pulsing FiberAlert are advanced troubleshooting features from B&B
Electronics that can help you locate “silent failures” on your network.
It is vital that you understand exactly how Pulsing FiberAlert and LinkLoss work and
how they will react in your network configuration before attempting to install the
enclosed unit.
WARNING
Installing media converters without understanding the effects of Pulsing FiberAlert
can cause perfectly functioning units to appear flawed or even dead!
If you are unfamiliar with Pulsing FiberAlert and LinkLoss, B&B Electronics strongly
encourages you to read the following information. Contact B&B Electronics technical
support at (800) 624-1070 (U.S./Canada), +32-16-550880 (Europe) or
support@bb-
elec.com
(U.S./Canada),
techsupport@bb-elec.com
(Europe) for more information
and assistance.
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About Link Integrity
During normal operation, link integrity pulses are transmitted by all point-to-point
Ethernet devices. When an B&B Electronics media converter receives valid link
pulses, it knows that the device to which it is connected is up and sending pulses, and
that the copper or fiber cable coming from that device is intact. The appropriate
“LINK” LED is lit to indicate this. The B&B Electronics media converter also sends out
link pulses from its copper and fiber transmitters, but normally has no way of knowing
whether the cable to the other device is intact and the link pulses are reaching the
other end. The combination of FiberAlert and LinkLoss allows this information to be
obtained, even when physical access to a remote device (and its link integrity LED) is
not available.
FO LinkLoss
FO LinkLoss is a troubleshooting feature. When a fault occurs on the fiber segment
(receive side) of a conversion, FO LinkLoss detects the fault and passes this
information to the twisted pair segment. If a media converter is not receiving a fiber
link, FO LinkLoss disables the transmitter on the media converter's twisted pair port.
This results in a loss of link on the device connected to the twisted pair port.
TP LinkLoss
TP LinkLoss is another troubleshooting feature. When a fault occurs on the twisted
pair segment of a conversion, TP LinkLoss detects the fault and passes this
information to the fiber segment. If a media converter is not receiving a twisted pair
link, TP LinkLoss disables the transmitter on the media converter's fiber port. This
results in a loss of link on the device connected to the fiber port.
Configuring LinkLoss
TP LinkLoss and FO LinkLoss are always enabled on McBasic TP/FO.