While tuning a GV/GV6 drive in position mode(DMODE6 - GV) or drive/controller mode(DMODE12 - GV6), if the load being tuned is over 20/1 load-to-rotor inetia ratio, conventional tuning methods may not work. We do not recommend using our motors with this large of an inertia mismatch, but if you have this scenario, you can still possibly tune the system to fit your positioning needs. Keep in mind that it will be difficult to get a crisp response from a system with a large inertia mismatch, but the following procedures can help to eliminate oscillations and instability:
Normally the LJRAT should to be set to the calculated load-to-rotor inertia ratio, but with values larger than 20, significant oscillations may be present when enabling the drive. If this is the case, start off with a lower LJRAT value, or a value of 0. If oscillations are still present with LJRAT0, turn the integrator off with SGINTE0. With this tuning, the system will be sluggish, so DPBW should be incremented to increase the position bandwith.