5 Adjustments5.8.1 Feedforward Reference5-505.8.1 Feedforward ReferenceApplies feedforward control compensation in position control inside the SERVOPACK . Use this parameter to shortenpositioning time.Note: Too high value may cause the machine to vibrate. For ordinary machines, set 80% or less in this parameter.5.8.2 Using the Mode Switch (P/PI Switching)Use the mode switch (P/PI switching) function in the following cases:P Control: Proportional controlPI Control: Proportional/integral control• To suppress overshooting during acceleration or deceleration (for speed control)• To suppress undershooting during positioning and reduce the settling time (for position control)The mode switch function automatically switches the speed control mode between PI control mode and P con-trol mode based on a comparison between the servo’s internal value and a user-set detection level shown in (1)Other Adjustment Functions.• Monitoring the speed response waveform and position error waveform is required for adjustment.• If I-P control is selected for speed loop control, the mode switching function will be disabled.Pn109Feedforward Gain ClassificationSetting Range Setting Unit Factory Setting When Enabled0 to 100 1% 0 Immediately TuningPn10AFeedforward Filter Time Constant ClassificationSetting Range Setting Unit Factory Setting When Enabled0 to 6400 0.01 ms 0 Immediately TuningPositionreferenceEncoder feedback pulse+ + +-Position loopgain㧔Kp㧕Pn109 Pn10ADiffer-entialPositionPositionActual servomotor operationOvershootSpeedReferenceSettling timeTimeUndershoot
