Installation and Reference Manual
Technical Data
342
Installation and Reference Manual v3.2/0410/6
BRI Short Haul Cross-over Dongle
The short haul dongle should be used to connect to a slaved device within 10m of the trunk connector,
i.e. the cable connected to the dongle should be <10m. This is to ensure signal quality. Exceeding 10m
may cause a high error rate on the link and, although generally operational, is not advised.
RJ45 connector
pin out
RJ45 Connector
pin out
1
1
2
2
3
4
4
3
5
6
6
5
7
7
8
8
A 50 Ohm resistor is connected across pins 3 & 6 of the first RJ45 connector.
A 50 Ohm resistor is connected across pins 4 & 5 of the first RJ45 connector.
BRI Long Haul Cross-over Dongle
The long haul dongle should be used when the slaved device is further than 10m from the trunk
connector. The pin out is the same as the short haul dongle but the termination resistors change, i.e.
RJ45 connector
pin out
RJ45 Connector
pin out
1
1
2
2
3
4
4
3
5
6
6
5
7
7
8
8
A 100 Ohm resistor is connected across pins 3 & 6 of the first RJ45 connector.
A 100 Ohm resistor is connected across pins 4 & 5 of the first RJ45 connector.
Further 100 Ohm termination is required at the slaved device to ensure signal quality. This is usually
provided by either another (but different) dongle or a patch panel containing the termination. These
devices are generally available from RS Components or Farnell, however for completeness the dongle
can be made up as follows:
RJ45 connector
pin out
RJ45 Connector
pin out
1
1
2
2
3
3
4
4
5
5
6
6