0V WIRE

I'm not sure if this is the right place to ask this question, but on a Fanuc control what does the 0V side do, it's usually tied in with the 24V. I have been having problems with a turret count proximity switch on a Citizens F-16.

With the 0v wire disconnected (also has 24V and output wire) I get a signal from the switch, and with it connected I get nothing. Either way it doesn't react to the cam that moves past it to create the count signal.

I had another switch in there that was working, but intermittenly the machine would stop and I had to write the turret position in MDI or it wouldn't sense the right turret count and not engage the shot pin.

Any ideas?

Thanks

0V is the 24vdc common, if you have a 3 wire proximity switch, then it requires both 24v and common (0v) as well as the signal wire to operate properly.
If you have it connected correctly and it does not read a metal flag in front of it, then it sounds as though it is defective?
Al.

Seen some slightly older equipment use pull up resistors. Check your prints, see if it has one. A shorted switch can take them out.

Thank You!

I'm not familiar with the pull up resistors, what do they look like and what should I look for.

I should have a new switch early next week, we'll see if it works.

Most Fanuc control inputs supply the load required for most prox.
Al.