How Do You Wire a GPIB Cable??
I started with a cable assembly with DB25 on one
end and a GPIB connector on the other (dual male/female
back to back stackable assembly).
It's wired wrong for what I want, so I need to rewire it.
But how?
The cable has enough twisted pairs for each signal line.
But there are only 7 ground pins. It's a dual insulation
displacement connector, so I can only put one wire in
each slot.
The original wiring had been modified and looks like the
connector is even on backwards, but it looks like
pairs of data lines are twisted together??
My first thought is to make sure DAV, NRFD and NDAC
have a complementary ground connection and make a big solder
blob
that connects all the other groun
ds together...But I'd still
need to use the correct ground pin so an extension cable
would continue the pairing properly.
This make sense?
What's the "right" way to allocate the twisted pairs and
grounds?
I suppose I could TDR a "real" GPIB cable and determine the
pairings
from that...assuming there's a standard.
The end result will be a parallel port to GPIB adapter that
implements
a subset of the GPIB hardware/software to control one
instrument.
There was a circuit cellar article that demonstrated
feasibility
of this approach.
Thoughts on that?
One more question.
Where can I find a datasheet for the NEC D7210C so I can
write my
own driver for a GPIB-PC card? If I could make the cards
work with
my win98/VB6 programs, I wouldn't need the parallel port
cable.
Thanks,
mike
spamme0@juno.com
