CABLES

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 these switches, you can use either straight-through or crossover cable.

Table B-1 10/100BASE-TX MDI and MDI-X Port Pinouts

Pin

MDI Signal Name

MDI-X Signal Name

1

Transmit Data plus (TD+)

Receive Data plus (RD+)

2

Transmit Data minus (TD-)

Receive Data minus (RD-)

3

Receive Data plus (RD+)

Transmit Data plus (TD+)

6

Receive Data minus (RD-)

Transmit Data minus (TD-)

4,5,7,8

Not used

Not used

Note: The “+” and “-” signs represent the polarity of the wires that make up each wire pair.

B-2

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Image 68
SMC Networks SMC8848M manual 10BASE-T/100BASE-TX Pin Assignments, Table B-1 10/100BASE-TX MDI and MDI-X Port Pinouts