- difference between an rs232 female-to-female and male-to-male pinout
- Posted by Perdition on November 15th, 2005
is there a difference between the pinouts? I can't find a site that
illustrates male-to-male and female-to-female with an explaination for
the cabling. Thanks for your time 
- Posted by Nico Kadel-Garcia on November 15th, 2005
"Perdition" <nhnmp@walla.co.il> wrote in message
news:1132043228.141785.73320@g43g2000cwa.googlegro ups.com...
It Depends(TM). The RS-232 standard, specifically RS-232c, is a 25-pin
standard with lots and lots and lots of signals that nobody in their right
mind uses. The common pin-out for DB9 connectors is. umm, how can I say
this. "circumcised", as in clipping off the bits you don't carry useful
signal and that can cause problems.
I personally find the old Yankee Electronics quite useful in describing
various pinouts, and various adapters, showing the differences between DTR
and DSR connectors. Modems, in particular, need to carry the ring-detect
signal and the hardware flow control signals, so the common pin-outs for
DB-9 are fairly odd. I don't have the better references in my bookmark list
right now, but it's worth poking around.
In particualr, a lot of modern female-female cables violate the spec by
being simple straight-through cables instead of being a null-modem cable,
which drives me nuts.
- Posted by Aaron Leonard on November 15th, 2005
Male vs female per se makes no difference to the pinning. What makes
a difference wrt pinning is:
- connector type used (DB25 vs. "DB9" [actually DE9]) vs. RJ45 vs ...)
- DCE vs DTE
- implementation oddities in the DTE (and, less frequently, in the DCE)
There are *conventions* for specific connector types wrt whether a DCE
is male or female. For example, with DB25 the convention is that both
the DTE and DCE are female, while with DB9 the convention is for DTE to
be male and DCE female.
Here's some good links on the subject:
http://www.arcelect.com/rs232.htm (cablish perspective)
http://www.beyondlogic.org/serial/serial.htm (PC / logic board perspective)
http://nemesis.lonestar.org/referenc...ms/dtedce.html
(good table of pinouts, although be aware that the RJ45 pinouts are totally
different from Cisco's assignments)
Cheers,
Aaron
---
~ is there a difference between the pinouts? I can't find a site that
~ illustrates male-to-male and female-to-female with an explaination for
~ the cabling. Thanks for your time 
- Posted by Perdition on November 16th, 2005
thanks alot for the input nico and aaron 
- Posted by Nico Kadel-Garcia on November 17th, 2005
"Perdition" <nhnmp@walla.co.il> wrote in message
news:1132120458.942447.105220@f14g2000cwb.googlegr oups.com...
No sweat. And despite the misdesign of a lot of devices, there *IS* a
standard for mail RS-232 that differs from female RS-232, so that in theory
if one device has a male connector and another has a female connector, you
just connect a straight cable between them and you can communicate both
ways. The difference is normally referred to as DTE and DCE. I found a nice
tutorial at http://www.arcelect.com/rs232.htm, which you may ennoy if you
want to see how it really works.