Allied Telesis AT-MCF12VF, SM - Manual (Page 16)

6
Note
The multichannel media converter will not pass network data when the
Link Test switch is in the Link Test position. For normal network
operations, the switch must be set to the Normal setting.
Reset Button
The Reset button allows you to reset the ports on the unit. You might need to
reset the ports after completing the installation or after adding or swapping a
power supply. You must reset the unit after a power disruption or whenever a
general power failure status is observed.
MissingLink Feature
The MissingLink

feature enables the twisted pair and fiber optic ports of
each channel on the media converter to pass the “Link” status of their
connections to each other. When a channel detects a problem with one of the
ports, such as the loss of connection to a node, the channel shuts down the
connection to the other port of the channel, thus notifying the node that the
connection has been lost.
For example, Figure 5 illustrates the two ports of Channel 1 on an
AT-MCF6xx unit. The twisted pair port in Channel 1 is connected to a port on
an AT-8224XL Ethernet switch and the fiber optic port is connected to an
AT-3714FXL/SC Ethernet switch. If the fiber optic cable of the AT-3714FXL/
SC switch experiences a failure, the MissingLink feature in the channel will
detect the problem and drop the link on the twisted pair port. In this way, the
AT-MCF6xx unit notifies the AT-8224XL Ethernet switch that the connection
to the AT-3714FXL/SC Ethernet switch has been lost. Had the failure started
with the twisted pair cabling, the MissingLink feature would have dropped
the link to the fiber optic port.
Figure 5 MissingLink Example
Tx
Rx
Tx
Rx
Tx
Rx
7
8
9
T-LNK
F-LNK
Active
7 7
7
Connected to an
AT-8224XL Ethernet
switch Connected to an
AT-3714FXL/SC
Ethernet switch