Appendix b: cables, Twisted-pair cable and pin assignments, 10base-t/100base-tx pin assignments – Milan Technology MIL-SM4804G User Manual

Page 51: Appendix b: cables b-1, Figure b-1, Rj-45 connector pin numbers

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B-1

Appendix B: 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.

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.

Caution:

Each wire pair must be attached to the RJ-45 connectors in a specific
orientation. (See “Straight-Through Wiring” and “Crossover Wiring” on the
next page 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.

Figure B-1 RJ-45 Connector Pin Numbers

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 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).

The RJ-45 ports on the switch base unit support automatic MDI/MDI-X operation, so
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.

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1

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