Delta ASD-B2-0121-B User Manual page 138

Chapter 6 Control Modes of Operation
Low-pass filter
Please use parameter P2-25. The figure below shows the resonant open-loop gain.
Gain
Frequency
When the low-pass filter (parameter P2-25) is adjusted from 0 to high value, the value of
Low-pass frequency (BW) will become smaller (see the figure below). The resonant
condition is improved and the frequency response and phase margin will also decrease.
Gain
0dB
Frequency
BW
Notch Filter
Usually, if the users know the resonance frequency, we recommend the users can
eliminate the resonance conditions directly by using notch filter (parameter P2-23, P2-24).
However, the range of frequency setting is from 50 to 1000Hz only and the range of
resonant attenuation is 0~32 dB only. Therefore, if the resonant frequency is out of this
range, we recommend the users to use low-pass filter (parameter P2-25) to improve
resonant condition.
Please refer to the following figures and explanation to know how to use notch filter and
low-pass filter to improve resonant condition.
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Revision June 2010