B&B Electronics 855-12840--49 - Manual User Manual

Page 9

Twisted Pair Crossover/Straight-Through Connections

Whether using crossover or straight-through CAT5 twisted pair cabling, all
Switching Modules will support both types of connections by one of the
following methods:

AutoCross

McLIM TX/FX (-00) and McGigabit include AutoCross, a feature that
automatically selects between a crossover workstation or straight-
through connection depending on the connected device.

MDI-II/MDI-
X Switch

All McPIMs feature a 2-position switch, located at position S1 (see table
for location on boards), for selecting a crossover workstation
connection or straight-through connection.
The switch is labeled with “X” for a crossover connection (factory
default) and an “ll” for a straight-through connection. Select the
appropriate setting by moving the switch to the proper position before
installing the media conversion module. If uncertain whether crossover
or straight-through is needed, set the switch to the position that makes
the link LED glow.

Device-
Dependent

The end device connected to the McLIM TX/FX and TX/SX (-50)
determines the type of twisted pair connection: this McLIM does
include AutoCross or a MDI-II/MDI-X switch.

Twisted Pair Cable Distance

Some McPIM TP/FOs features a 2-position jumper, located at position JP2, for
selecting longer twisted pair cable distances (distances greater than 100 meters).
Place the jumper over both pins for distances up to 100 meters (factory default).
Remove the jumper shunt or place it on only one pin for distances of 100 meters
or more.

NOTE

The product on the other side of the conversion must be able to support longer

cable distances.

Twisted Pair Cable Type

Some McPIM TP/FOs (-20 and -40) features a 2-position jumper, located at
position JP3, for selecting either a shielded or unshielded twisted pair link
segment. Remove the jumper shunt or place it on only one pin to select an
unshielded twisted pair link segment (factory default). Place the jumper shunt
over both pins to select a shielded twisted pair link segment.