You would be wanting to measure between A or B and 0v, you would have to catch the pulse when high so not turning. If you had a scope then you could turn and measure the voltage but a voltmeter, especially a digital one, would be too slow. You should be able to move it to a position so that the pulse is high.
 I would think the resistor for the LED would be  for 12v, whether anything else is I am not sure. Dont think it would harm trying with 5v, however without a scope I dont think you will really see if it would be good enough to use.
Hood

    Well I don't know if I made a meaningful test or not. For starters I used an old computer power supply for testing, the 12v actually checked 10.5 v when connected to the mpg. Check from 0v to A = 0.75v, check from 0v to B =2.95v. Didn't matter if  mpg was sitting still, turned, or how slowly I turned the mpg to try and catch the "high spot" the readings never changed. I even tried a small analog vom to see if it would fluctuate and the results were same as digital vom ? So do these results shed any light on function of the mpg?

Rick   

Doesnt sound like its working, the voltages should change I would have thought.
Hood

    Maybe it needs something else that was in the Okuma to make it work? Here's what I know about this mpg, it was working in the machine I removed it from but had a small problem. There were two of the detent positions (not in a row) that were dead, machine didn't respond to those "clicks". Set-up people were complaining so I replaced the mpg. The Okuma replacement fixed the "dead spot" problem in the turning center and the old one was destined for the trash so I brought it home for my diy machine,(figured I could live with the two dead spots because the price was right.
    Oh well if I can't use it no biggie but I really like the heavy solid feel of it. What's the scoop on these mach3 pendants with mpg I see all over ebay, any good? Btw I see many are usb, would that work with my set-up without using up input pins on the breakout to PP? And lastly, if I had a usb pendant can you unplug it and still use a usb stick to get programs in the computer then go back to the pendant?

Rick

If the machine is at your work possibly you can get the electrical drawings, they may shed some light on what its looking for. However with it missing a couple of pulses it sounds like it was on its way out anyway so maybe not worth it.

Personally I am not a fan of hand held pendants, just seem to be always in the way for me, no place to put them down or whatever
I much prefer to have the MPG on my control panel, there are quite a few people that sell the stand alone MPGs, I prefer the 80mm dia ones but you can also get 60mm dia.

Regarding USB hand held pendants, not sure how good they would work for the MPG part, all depends on how well the plugin has been written.

Hood

    Ok, Thanks for your feedback Hood. I don't really want a pendant per say, but I want the mpg. Maybe  someday I might try a "touch plate" for Z height setting but I'm more used to the wiggle a piece of paper over part till trapped by the tool then add .003 and call that Z zero, mpg would be nice for that.

Rick

As I said quite a few places to get a standalone MPG. Seems less of the usual places in the USA stock them but I did see Keling did some, I think they are just the 60mm dia ones by the look of them, it doesnt say though.
Peter Homann in Ozz http://www.homanndesigns.com/store/index.php?main_page=product_info&cPath=15&products_id=29 sells them and I have had one from Peter and it was nice, his are differential where others are just single ended, you can still connect single ended if you wish  but with your newly found circuit making  skills you could easily make a receiver

Hood

     Ya Hood, your kinda talking about just what I was going to ask about. I've done a little looking at 5v input mpg's the last couple days. Some are 4 terminal Like the Okuma I have, (v+ , 0v , A , B), and others are 6 terminal with a B- , A- added to the other 4. I never have gotten an answer about why my BOB has 2 screw terminals for each input pin so I'm guessing here but if the mpg has differential output (6 terminals) then A+ and A- are going to go on 1 input pin  and B+ and B- are on the 2 screws of the other pin?
     If I'm correct about the differential output then single ended would be connected with A to 1 screw on input pin terminals and 0V on the other screw of the same input pin?

Rick

I am afraid I cant really remember the specifics of your breakout board, it may have differential inputs but I think it more likely that it is just a common connection at each input.
 To connect a differential MPG to a single ended connection you would just use the A+ and B+ and the 5v and 0v, you would leave the A- and B- unconnected.
Hood

    Ok, Thanks Hood. I think I got a deal working on the mpg that might take awhile to happen so that's on stand-by for a while. In the meantime I have another thing to figure out. But I'm wondering what's the right thing to do. I started this thread, "Panasonic servo drive help" because I wasn't getting communication between the drives and Mach 3. Thanks to help I found here that problem is solved , (Thanks to all). The next thing on my to do list is fitting a rotozip with a Super PID and controling it with Mach 3 as the spindle for my diy cnc.
    Should I keep posting in this thread as I tackle that phase of the build, or would it be best to start a new thread?

     Rick