I'm hooking up scales on my mill now.  They are working in that they are giving me feedback but no matter what I set the Feedback Gain to it doesn't change the feedback numbers, so I get following error issues.  Any idea why this would be/how to make it work correctly? 
Another thing about the feedback on the scales, the gain numbers are about 4X smaller than the stepper feedback.  I would have thought it would be significantly larger since the encoders are like 10nm resolution.  Probably something to do with the gain not working right, I'm guessing.
Also, for some reason, the encoders are showing up on index 3, 4 and 5 not 0, 1 and 2 like they should be.  I have a 7737 BOB for the steppers and encoders.  The steppers are on the right index, just the encoders are off.

Mike

I see from the J7 7737 pin assignments that they should be encoder channels 3, 4 and 5, so that's not a problem.  I still have no idea why the gain on the motors tabs in the Hicon plugin window aren't working at all.  The encoders are set to the correct index for each motor.

I'm looking thru the machine.ini file and it got me wondering if I have to have the PID enabled before the Gain works?  Reading the PID guide, it doesn't look like it needs to be enabled because they have you test it first, but who knows.  Unfortunately I'm out of town for work until probably this weekend so I won't be able to test it for a while.

Unfortunately I'm out of my warranty window, so I guess Vital won't help unless I pay like $500 for extra support.  Hoping I don't have to go that far!

Ok, I figured out what I was missing on here.  I was expecting the Encoder values to change with the Gain, but they don't.  The Feedback values get adjusted.  I'm still trying to find out exactly what the pulse values are for the Heidenhain scales I have, LC series, since a resolution of ~.0002" seems really huge for them.  I verified my wiring/pinout as best I could and it looks fine.  I was playing with the PID and the values I got in the picture are about the closest I could get the actual and commanded lines.  Much higher in the P and it didn't like it at all, lower and the lines diverge more.  This is the first time I've adjust PID, so if anyone has any suggestions I'm more than open to them!

I think I have everything working now.  I guess .005mm is the standard encoder resolution, which is what these are.  I did a lot of playing with the PID today and found that in order to get decent low feed movement I had to up the microstepping to 16. I was hoping I could get it down to 2 or 4, but it was very jerky there.  So far I'm pretty happy with where it is now.