This page gives
information
to
create
both
standard and reverse
patch cable wiring diagrams.
RJ-45 Standard Patch Cable
Wiring Diagram
If you hold the RJ-45 connector
facing you (as if you were going to plug it into your mouth) with
the lock tab/clip on the bottom, the pins are numbered 8 to 1
from left to right. The pin usage should be the same
for both ends of the cable and is as follows:
Standard
Patch Cable (Both Ends)
|
|
Pin Number
|
Assignment
|
Color
|
|
1
|
Output Data (+)
|
orange/white
|
|
2
|
Output Data (-)
|
orange solid
|
|
3
|
Input Data (+)
|
green/white
|
|
4
|
Reserved for Telephone use
|
blue solid
|
|
5
|
Reserved for Telephone use
|
blue/white
|
|
6
|
Input Data (-)
|
green solid
|
|
7
|
Reserved for Telephone use
|
brown/white
|
|
8
|
Reserved for Telephone use
|
brown solid
|
If you don't follow this exact
wiring or color scheme, you should at least wire your cable so
that the two output data conductors (1 & 2) make up one
twisted pair and the two input data conductors (3 & 6) make
up another twisted pair. (One "pair" consists of two
twisted wires: One wire is solid colored; the other wire
is the same color, but has a white stripe [orange solid & orange/white
are a pair]). If the cable is not paired
correctly
(mixing
colors
or
mistakenly using 3 & 4 on one pair and 5 & 6
on another pair or splitting the assignment types between pairs),
it may work for lengths less than a meter, but will fail
miserably for longer lengths.
RJ-45
Crossover
Patch Cable
Wiring Diagram
If you are connecting two
machines to each other, it is possible to avoid using a hub by swapping the
output data and input data pairs (1 & 2 swapped with 3 &
6, respectively).
This
change
is
all
that's
required
to
make
a
crossover
cable.
One end is wired as if the cable was going to
be a standard patch cable, while the other end is wired with the
input data and output data pairs swapped.
This swap feeds the
output data of one (local) computer to the input data of the
second (distant) computer, and vice-versa.
In other words, the
orange and green pairs are switched at one of the ends.
The
polarity at the switched end remains unchanged (stripes are still
strips and solids are still solids).
The pin usage for each end
of the cable is as follows:
Crossover
Patch Cable (RJ-45 End at Local Computer)
|
|
Pin Number
|
Assignment
|
Color
|
|
1
|
Output Data (+)
|
orange/white
|
|
2
|
Output Data (-)
|
orange solid
|
|
3
|
Input Data (+)
|
green/white
|
|
4
|
Reserved for Telephone use
|
blue solid
|
|
5
|
Reserved for Telephone use
|
blue/white
|
|
6
|
Input Data (-)
|
green solid
|
|
7
|
Reserved for Telephone use
|
brown/white
|
|
8
|
Reserved for Telephone use
|
brown solid
|
Crossover
Patch Cable (RJ-45 End at Distant Computer)
|
|
Pin Number
|
Assignment
|
Color
|
|
1
|
Input Data (+)
|
green/white
|
|
2
|
Input Data (-)
|
green solid
|
|
3
|
Output Data (+)
|
orange/white
|
|
4
|
Reserved for Telephone use
|
blue solid
|
|
5
|
Reserved for Telephone use
|
blue/white
|
|
6
|
Output Data (-)
|
orange solid
|
|
7
|
Reserved for Telephone use
|
brown/white
|
|
8
|
Reserved for Telephone use
|
brown solid
|
Again, if you don't follow this
exact wiring or color scheme, you should at least wire your cable
so that each data channel (its positive and negative signals)
uses both conductors of a twisted pair. If the cable is not
paired correctly, it may work for lengths less than a meter, but
will fail miserably for
longer lengths.
