Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Manual (Page 234)

6 Utility Functions (Fn )
6-32
6.21 EasyFFT (Fn206)
EasyFFT sends a frequency waveform reference from the SERVOPACK to the servomotor and rotates the ser-
vomotor at minimal speed a number of times over a certain period, thus causing machine vibration. The SER-
VOPACK detects the resonance frequency from the generated vibration and makes notch filter settings
according to the resonance frequency detection. The notch filter is effective for the elimination of high-fre-
quency vibration and noise.
Machine vibration may be suppressed by setting a notch filter according to the detected vibration frequency.
In addition to this function, Online Vibration Monitor (Fn207) can be used to detect machine vibration and
automatically make notch filter settings. Use the following flowchart to determine which function should be
used.
WARNING
• The servomotor rotates at minimal speed when EasyFFT is executed. Do not touch the servomotor or
machine during execution of EasyFFT, otherwise injury may result.
CAUTION
• Use the EasyFFT when the servo gain is low, such as in the initial stage of servo adjustment. If EasyFFT
is executed after increasing the gain, the servo system may vibrate depending on the machine character-
istics or gain balance.
Small
rotation
Small
movement
SERVOPACK
Reference
Response