D-Link DMC-920 - Function

Link Pass Through Function
LLR (Link Loss Return)
When a device connected to the converter and the fiber line
loss the link, the converter’s fiber will disconnect the link of
transmit.
The switch 5 is to enable or disable the LLR function of the
media converter.
TX RX
Sw i t c h B
Sw i t c h A
Cable 3
Cable 2
Cable 4
Cable 1
Media
Converter B
Media
Converter A
TX R X
LLCF Off
LLR Off
LLCF Off
LLR On
LINK 6
Copper
LINK 5
Copper
Copper
LINK 4
LINK FAIL 4
Fiber
LINK 3
LINK FAIL 3
Fiber
LINK 1
LINK FAIL 1
Copper
LINK 2
LINK FAIL 2
The table below shows the status happens when LLR function
is working through two ways of connection
Link
Status
Disconnect
Link
1
Link
2
Link
3
Link
4
Link
5
Link
6
Link
Fail 1
LED
Link
Fail 2
LED
Link
Fail 3
LED
Link
Fail 4
LED
Cable 1 On On Off On On On Off Off On Off
Cable 2 Off On Off On On On On Off On Off
Cable 3 On On On Off On Off Off Off Off On
Cable 4 On Off On On Off On Off On Off Off
Fib e r
Copper
TXRX
Fiber
Copper
Sw i t c h C
Sw i t c h D
LINK 8
LINK 3
LINK 1
LIN K 7
Cable 3
Cable 2
Cable 4
Cable 1
Media
Converter B
Media
Converter A
LIN K 2
LINK 4
LINK FAIL 4
LINK FAIL 3
LINK FAIL 1
LINK FAIL 2
LLCF Off
LLR Off
LLCF Off
LLR On
Fiber
TX RX
Fib e r
LINK 6
LINK 5
Sw i t c h A
Sw i t c h B
TXRX
TX RX
Cable 6
Cable 5
Copper
Copper
8