[geeks] QUESTION: RJ45 -> RS-232, using CAT5 cable

[Bill Bradford]

On Tue, May 29, 2007 at 05:12:43PM -0400, Charles Shannon Hendrix wrote:
> I need to make a 25 foot RS-232 cable, male on one end, female on the
> other.
> Parts I have:
> Two DB-25 hoods with RJ-45 connectors, one male, one female.  Pinouts:
> 	PIN			COLOR
> 	1			blue
> 	2			orange
> 	3			black
> 	4			red
> 	5			green
> 	6			yellow
> 	7			brown
> 	8			white
> 25 feet of RJ-45 standard CAT5 cable.
> What's the best wiring?

The pinouts I've been using, which are AFAIK the "cisco"/industry
standard (I've been making a lot of console server serial adapters,
the same type you're using):

RJ45F to DB25M
DB25	FUNC	Color	RJ
2	RX	Yellow	6
3	TX	Black	3
4	CTS	White	8
5	RTS	Blue	1
6	DTR	Orange	2
7	GND	Red	4
20	DSR	Brown	7
X	X	Green	9

RJ45F to DB9F
DB9	FUNC	Color	RJ
1	X	Green	X
2	TX	Black	3
3	RX	Yellow	6
4	DSR	Brown	7
5	GND	Red	4
6	DTR	Orange	2
7	CTS	White	8
8	RTS	Blue	1

If I need null-modem, I just use a Cisco blue console cable that "flips"
the RJ45 wiring, or use an inline coupler that does the same thing.

Bill

-- 
Bill Bradford 
Houston, Texas