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10/100base-tx pin assignments – SMC Networks SMC TigerStack III SMC6826MPE User Manual

Page 70

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C

ABLES

B-2

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 and PoE power are delivered on the standard two wire pairs (pins 1,
2, 3, and 6). 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.

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

Pin

MDI Signal Name

MDI-X Signal Name

1

Receive Data plus (RD+)

and GND (Positive V

port

)

Transmit Data plus (TD+)

and -48V feeding power

(Negative V

port

)

2

Receive Data minus (RD-) and

and GND (Positive V

port

)

Transmit Data minus (TD-)

and -48V feeding power

(Negative V

port

)

3

Transmit Data plus (TD+)

and -48V feeding power

(Negative V

port

)

Receive Data plus (RD+)

and GND (Positive V

port

)

6

Transmit Data minus (TD-)

and -48V feeding power

(Negative V

port

)

Receive Data minus (RD-)

and GND (Positive V

port

)

4, 5, 7, 8

Not used

Not used

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

each wire pair.