User's Manual

Chapter 4: Install the High-Density Media Converter System II Layer 2
Modules
Page 12 724-746-5500 | blackbox.com LMC5022C-R3
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 “LNK” (link) LED is lit to indicate this.
The Black Box 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.
4.3.2 FX LinkLoss (FXLL)
FX LinkLoss is a troubleshooting feature. When enabled, if a fault occurs on
the fiber segment of a conversation, FX LinkLoss detects the fault and passes
this information to the twisted pair segment. If a media converter is not
receiving a fiber link, FX 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.
4.3.3 TX LinkLoss (TXLL)
TX LinkLoss is a troubleshooting feature. When enabled, if a fault occurs on
the twisted pair segment of a conversion, TX LinkLoss detects the fault and
passes this information to the fiber segment. If a media converter is not
receiving a twisted pair link, TX LinkLoss disables the transmitter on the media
converter's fiber port. The result is in a loss of the link on the device connected
to the fiber port.
4.3.4 Link Fault Pass-Through (LFPT)
Link Fault Pass-Through (LFPT) is a troubleshooting feature that combines TX
and FX LinkLoss from both the local and remote L2 modules. LFPT is enabled
by turning on both FX and TX LinkLoss on both modules. This feature allows
either end of the conversion to detect a link fault occurring at the other end of
the media conversion chain.