RJ45

Pinouts for RJ45 jacks (Serial and 10Base-T)

A 10Base-T cable is wired with a straight thru cable. Often either T568A or T568B is used instead of 10Base-T wiring:

**10Base-T Wiring Chart**
Pin	Color	Signal
1	White-Blue	TD+
2	Blue	TD-
3	White-Orange	RD+
4	-	-
5	-	-
6	Orange	RD-
7	-	-
8	-	-

**T568A Wiring Chart**
Pin	Color	Signal
1	White-Green	T3
2	Green	R3
3	White-Orange	T2
4	Blue	R1
5	White-Blue	T1
6	Orange	R2
7	White-Brown	T4
8	Brown	R3

**T568B Wiring Chart**
Pin	Color	Signal
1	White-Orange	T2
2	Orange	R2
3	White-Green	T3
4	Blue	R1
5	White-Blue	T1
6	Green	R3
7	White-Brown	T4
8	Brown	R4

A 10Base-T Cross-over swaps TD and RD. That is, swap pins 1 and 3 as well as pins 2 and 6, on one end of the cable.

AT&T 258A wiring is comparable to T568B

Serial cables must be pin-swapped ( 1 - 8, 2 - 7, etc.) The serial pinout is the same as used by SCCS, though the documentation in the USENET Serial Board II Owner's Manual has the pin numbering swapped from above. These are their tables, modified for the above pin numbering. The USOC 4-Pair wiring can be used (swapping one side)

**USOC 4-Pair Wiring Chart**
Pin	Color	Signal
1	White-Brown	T4
2	White-Green	T3
3	White-Orange	T2
4	Blue	R1
5	White-Blue	T1
6	Orange	R2
7	Green	R3
8	Brown	R4

**Serial Pinout Applications**
Connector	Pinout	Connect to	Pretend to be
DB25-M	DCE	Modem	IBM PC 25-pin
DB25-M	DTE	Terminal
DB25-F	DTE	IBM PC 25-pin	Modem
DE9-M	DCE	Mouse	IBM PC 9-pin
DE9-F	DTE	IBM PC 9-pin

**Serial Pinout Details**
RJ45 Pin	Wire Color	DTE			DCE
RJ45 Pin	Wire Color	Name	DE9	DB25	Name	DB9	DB25
1	blue	CTS	8	5	RTS	7	4
2	orange	DCD	1	8	DTR	4	20
3	black	TD	3	2	RD	2	3
4	red	Gnd	5	7	Gnd	N/C	1
5	green	Gnd	N/C	1	Gnd	5	7
6	yellow	RD	2	3	TD	3	2
7	brown	DTR	4	20	DCD	1	8
8	white	RTS	7	4	CTS	8	5

Make Equinox terminal server cables as straight through with pins 5 and 6 swapped on the Equinox side.

On cisco routers, as well as SPARC Netras, RJ45 jacks are also used. The wiring is slightly different than the one listed above. They have RTS/CTS flipped as well as DTR and DCD (actually, they use DSR instead of DCD). Below is a table that reflects these changes.

**Serial Pinout Details - cisco**
RJ45 Pin	Wire Color	DTE			DCE
RJ45 Pin	Wire Color	Name	DE9	DB25	Name	DB9	DB25
1	blue	RTS	7	4	CTS	8	5
7	orange	DTR	4	20	DSR	1	6
3	black	TD	3	2	RD	2	3
4	red	Gnd	5	7	Gnd	5	7
5	green	Gnd	5	7	Gnd	5	7
6	yellow	RD	2	3	TD	3	2
7	brown	DSR	1	6	DTR	4	20
8	white	CTS	8	5	RTS	7	4

BayTech RPC and DS series data switches and power controllers have yet another pinout. Below is a table that reflects their pinout.

**Serial Pinout Details - BayTech**
RJ45 Pin	Wire Color	DTE			DCE
RJ45 Pin	Wire Color	Name	DE9	DB25	Name	DB9	DB25
1	blue	DTR	4	20	CTS	8	5
7	orange	N/C	-	-	GND	5	7
3	black	RTS	7	4	DSR	1	6
4	red	TX	3	2	RD	2	3
5	green	RD	2	3	TD	3	2
6	yellow	DSR	1	6	RTS	7	4
7	brown	GND	5	7	N/C	-	-
8	white	CTS	8	5	DTR	4	20

If you are using a 10baseT patch cable to connect two serial ports, one end must be changed from DTE to DCE or DCE to DTE.

The wire colors given here are those used in the adapters offered by South Coast Computing Services, Inc. Verify the color code of any connector you use by comparing pin numbers and configuration with the pin number map in figures 1 and 2.