The G320X can be tuned with either an oscilloscope or by ear to ensure that it is maintaining position while under load. The guide below is the quickest way to tune the drive without an oscilloscope and will result in a rigid motor shaft that will maintain position under any load.
1) Set the G320X following error limit switches to 1/2 of your encoder line count. If you use a 500-line encoder, set the following error switches to +/- 256.
2) Turn the "I" trimpot fully off (CCW).
3) The "D" term setting HAS to lead the "P" term. Turn "D" up first, then "P", turn "P" down first before turning "D" down. You can get violent motor oscillations if you don't follow this rule.
4) Set "P" and "D" to 1/4 full scale. The "D" term is what causes all the noise. Turning it down decreases motor humming, turning it up increases motor humming.
5) Turning "P" increases servo stiffness, turning "P" down decreases it.
6) Adjust "D" and "P" until you have OK servo stiffness. Try to turn the motor using your thumb and index finger. A stiff servo will resist a lot, a loose servo will resist very little.
7) Make the settings where the servo is reasonably stiff while making little or no noise.
8) Now adjust the "I" term CW. It will greatly increase servo stiffness. Once it's adequate, let it be. You are done. The motor will be very quiet and it will be very stiff (resist being moved).