RJ45 to RS-232 Db 25 and Db9

[SysAdmMke]

I am making a straight cable db25 to db9 connection using CAT 5 wiring. What I am wondering is what is the standard for the color code for serial communications?

Thanks
Mike

 

[edfair]

No standard that I have ever seen. There are standards for the pins in a D connector but no standard on colors used there. And no standards on the RJ45 with regards to RS232 transmission.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[SYQUEST]

That is why in the old days we called it "the RS232 NON-standard"! Now they call it EIA232C or is it D, but it is still NON-standard or what ever you can get away with!

....JIM....

 

[robertjo24]

This is what was listed in an equipment's manual. I have used it as a defacto standard. I hope you find this helpful.

Signal RJ45 Pin
TXD 3
RXD 6
DTR 2
DSR 8
DCD 7
RTS 1
CTS 5
GND 4

The color code on the RJ-45 to DB-X adaptors are:
1 Blue
2 Orange
3Black
4 Red
5 Green
6 Yellow
7 Brown
8 White

When cabling up a DB9 connector, I ususlly put Black to pin 2, Yellow to pin 3, and Red to pin 5. I don't usually use the other wires as I typically either edon't use handshaking or I short RTS (DB9 pin 7) and CTS (DB9 pin 8)together.

 

[ttech]

Google EIA/TIA-561

 

[SysAdmMke]

Actually what I was wondering if the color codes from RJ45 to DB9 to DB25 were.

Example:

Blue - Pin 2 on DB9
Blue/White - Pin 3 on DB9
Orange - Pin 4
Orange/White pin 5 on DB9

Or do I just make up my own colors? I am just saying if there was a standard for this I would follow it.

Thanks
Mike

 

[robertjo24]

For DB9
Black to pin 2
Yellow to pin 3
Red to pin 5
The rest do not matter unless you are using handshaking. If using RTS & CTS, use Blue to pin 7 & Green to pin 8.

For DB25
Yellow to pin 2
Black to pin 3
Red to pin 7
If you need RTS & CTS
Blue to pin 4
Green to pin 5

 

[ttech]

There IS a standard it is EIA TIA 561

here

and

here

 

[robertjo24]

Thanks ttech, I had not seen this before.

 

[macphoneguy]

if you goto

http://bb-elec.com/tech_articles/faq_rs232_connections_work.asp

they have a RS232 connections that work document it helped me see the forest through the trees, it helped determine if what I had was DCE or DTE equipment once you know that for sure the rest is easy