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Page 22
Chapter 5: Operation
5.3 Link Fault Pass Through Function
In common situations, when one side of the link fails, the other side continues
transmitting packets and waits for a response that never arrives from the
disconnected side.
With the Link Fault Passthrough function enabled (optional with switch LFP), the TP
port and FX port of the same converter will tell each other the fault link status so
that when one side of the link fails, the other side will force the link to shut down as
soon as noticed. See Figure 5-3.
Device A
Device B
LHC201A
or
LHC202A
LHC201A
or
LHC202A
TP Port A
link failed
Fiber Port A
sends non-idle
pattern
Fiber Port B
gets link fault
information
TP Port B
link failed
Fiber cable
UTP
cable
UTP
cable
Figure 5-3. Link Fault Passthrough.
If link fail happens on TP port (A), the FX port (A) sends a non-idle pattern to notice
the FX port (B). The FX port (B) then forces its TP port (B) to link failed after
receiving the non-idle pattern. Link status LED will also be off for both converters
and devices as shown in Table 5-4.
