Installation guide

Cables
B-2
Twisted-Pair Cable and Pin Assignments
Caution: DO NOT plug a phone jack connector into any RJ-45 port. Use only twisted-pair
cables with RJ-45 connectors that conform with FCC standards.
For 10BASE-T/100BASE-TX connections, a twisted-pair cable must have two pairs
of wires. Each wire pair is identified by two different colors. For example, one wire
might be red and the other, red with white stripes. Also, an RJ-45 connector must be
attached to both ends of the cable.
Caution: Each wire pair must be attached to the RJ-45 connectors in a specific
orientation. (See “Cabling Guidelines” on page 4-1 for an explanation.)
The figure below illustrates how the pins on the RJ-45 connector are numbered. Be
sure to hold the connectors in the same orientation when attaching the wires to the
pins.
10BASE-T/100BASE-TX Pin Assignments
Use unshielded twisted-pair (UTP) or shielded twisted-pair (STP) cable for RJ-45
connections: 100-ohm Category 3, 4 or 5 cable for 10 Mbps connections or 100-ohm
Category 5 cable for 100 Mbps connections. Also be sure
that the length of any
twisted-pair connection does not exceed 100 meters (328 feet).
The RJ-45 ports on the switch base unit support automatic MDI/MDI-X operation,
you can use straight-through cables for all network connections to PCs or servers, or
to other switches or hubs. In straight-through cable, pins 1, 2, 3, and 6, at one end of
the cable, are connected straight through to pins 1, 2, 3, and 6 at the other end of
the cable. When using any RJ-45 port on this switch, you can use either
straight-through or crossover cable.
Pin MDI-X Signal Name MDI Signal Name
1 Receive Data plus (RD+) Transmit Data plus (TD+)
2 Receive Data minus (RD-) Transmit Data minus (TD-)
3
Transmit Data plus (TD+) Receive Data plus (RD+)
6
Transmit Data minus (TD-) Receive Data minus (RD-)
4,5,7,8
Not used Not used
Note: The “+” and “-” signs represent the polarity of the wires that make
up each wire pair.