25 Aug
2014
25 Aug
'14
1:05 p.m.
While I'm prepping parts for P112 kits, I started thinking about DE-9
pigtails. These things come in two different pinouts. One of them is
pin-1 of the header connects to pin-1 on the DE-9. When wiring up a
pigtail like this manually, you cut the ribbon cable into two sections.
One sections goes on the top row of the DE-9. The other section goes on
the bottom. The other one has the pins interleaved. See
http://661.org/p112/files/pigtail.pdf for what I mean.
The P112 was designed with the second pinout in mind. When I bought
pigtails for my first run of P112s, I managed to get that kind. For
subsequent runs, I always got the first kind. Which pinout is more common
with actual devices? I ask this because I'm tinkering with an amateur
radio project that will eventually use DE-9 pigtails.
I've only ever seen the ones you call 'interleaved'. Actually, I rarely
buy such things, I make my own, If you use IDC DE9 connectors you get the
interleaved pinout. And if you solder the DE9 end I find it easier to
interleave the wires (split the cable between each wire, fold back the
even numbered wires. solder the odd-numbered wires to the row of 5 pins,
athen turn the conenctor roudn and solder teh even numbered wires to the
row of 4 pins) than to sodler the first 5 wires to the row of 5 pins then
take the remaing 4 wiires from teh side of the bakc back to the conenctor
and solder them to the wor of 4 pin.
So I would certianly stick with the interleaved pinout.
-tony