User manual

Cables
31
NXA-ENET24 Hardware Installation Guide
Cables
Twisted-Pair Cable and Pin Assignments
For 10/100BASE-TX connections, the twisted-pair cable must have two pairs of wires. For 1000BASE-
T connections the twisted-pair cable must have four pairs of wires. Each wire pair is identified by two
different colors. For example, one wire might be green and the other, green with white stripes. Also, an
RJ-45 connector must be attached to both ends of the cable.
Figure B-1 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.
10/100BASE-TX Pin Assignments
Use unshielded twisted-pair (UTP) or shielded twisted-pair (STP) cable for RJ-45 connections: 100-ohm
Category 3 or better cable for 10 Mbps connections, or 100-ohm Category 5 or better cable for 100 Mbps
connections. Also be sure
that the length of any twisted-pair connection does not exceed 100 meters (328
feet).
Data is delivered on the standard two wire pairs (pins 1, 2, 3, and 6), and PoE power is supplied using the
two previously spare pairs (pins 4, 5, 7, and 8). Since 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.
DO NOT plug a normal phone jack connector into any RJ-45 port. Use only twisted-
pair cables with RJ-45 connectors that conform with FCC standards.
Each wire pair must be attached to the RJ-45 connectors in a specific orientation.
(See “Cabling Guidelines” on page 23. for an explanation.)
FIG. 24 RJ-45 Connector Pin Numbers