6 Adjustments6.9.6 Torque Reference Filter6-726.9.6 Torque Reference FilterAs shown in the following diagram, the torque reference filter contains first order lag filter and notch filtersarrayed in series, and each filter operates independently. The notch filters can be enabled and disabled with thePn408.(1) Torque Reference FilterIf you suspect that machine vibration is being caused by the servo drive, try adjusting the filter time constantswith Pn401. This may stop the vibration. The lower the value, the better the response will be, but there may bea limit that depends on the machine conditions. Torque Reference Filter Setting GuideUse the speed loop gain (Pn100 [Hz]) and the torque filter time constant (Pn401 [ms]) to set the torque refer-ence filter.Adjusted value for stable control: Pn401 [ms] ≤ 1000/ (2π × Pn100 [Hz] × 4)Critical gains: Pn401 [ms] < 1000/ (2π × Pn100 [Hz] × 1)∗ The filter is disabled if 5000 is set.TorquereferencebeforefilteringTorque RelatedFunction SwitchPn408Notch filter Notch filterFirst order lag filterTorquereferenceafterfilteringSecond order lag filter2ndNotchFilter(Pn40C,Pn40D, andPn40E)1st NotchFilter(Pn409,Pn40A,and Pn40B)* The 2nd torque reference filter is enabled when Pn40F is set to a value less than5000 and disabled when Pn40F is set to 5000 (factory setting).*TorqueReferenceFilter(Pn401)2ndTorqueReferenceFilter(Pn40F,Pn410)RotationPn401Torque Reference Filter Time Constant ClassificationSetting Range Setting Unit Factory Setting When Enabled0 to 65535 0.01 ms 100 Immediately TuningSpeed Position TorquePn40F2nd Step 2nd Torque Reference FilterFrequency ClassificationSetting Range Setting Unit Factory Setting When Enabled100 to 5000 1 Hz 5000 * Immediately TuningPn4102nd Step 2nd Torque Reference FilterQ Value ClassificationSetting Range Setting Unit Factory Setting When Enabled50 to 100 0.01 50 Immediately TuningSpeed Position TorqueSpeed Position Torque
