On Mon, 27 Sep 2010 11:19:39 -0700, "Paul Hovnanian P.E."
wrote:

Karl Townsend wrote:

I pulled to the old servo drives out of my Matsurra bed mill and got
all the wire run cables separated as much as possible. Most of the I/O
cables have less than ten conductors and you can deduce what they are
for by where the cable run goes.

I have two fifty conductor cables that go to the operator panel. I'm
guessing fifty inputs on the operator panel so there are a great many
more wires than used. I have no manual for this machine and these
wires aren't numbered. Looks like a REAL MESS to figure out the
function of each wire.

Each input is pretty simple, if it is made it conducts voltage. But
doing this many at once becomes a snow storm. Any suggestions on best
approach?

Karl

Are the cables still connected to controls or whatever at one end? If so,
any continuity test might be confused by sneak paths through the controls
(multiple conductors will be connected through closed contacts or low
impedance relay coils).

If there are terminal blocks available, its best to disconnect one conductor
at a time and test it at the (disconnected) far end of a cable. That
doesn't take as much time as it sounds. I use a continuity tester with an
audible signal and brushing the probe over all the free conductors a few
times, listening for the beep narrows it down pretty rapidly.

Yep, this is the point everybody missed. The operator panel is all
soldered up and I don't want to take anyting apart in there. it would
ruin it. I don't need to just trace a wire from one end to the other,
I need to know which wire is connected to which switch.

Karl