Rockwell Automation 1784-PM16SE SoftLogix Motion Card Setup and Configuration Manual - Manual (Page 151)

Publication 1784-UM003A-EN-P – June 2003
Naming & Configuring Your Motion Axis 143
Enable Low-pass Output Filter
Select this to enable the servo’s low-pass digital output filter. De-select this to
disable this filter.
Note: During tuning, if the controller detects a high degree of tuning
inertia, it enables the Low Pass Output Filter and calculates and sets a
value for Low Pass Output Filter Bandwidth.
Low-pass Output Filter Bandwidth
With Enable Low-pass Output Filter selected, this value sets the bandwidth, in
Hertz, of the servo’s low-pass digital output filter. Use this output filter to filter
out high frequency variation of the servo module output to the drive. All
output from the servo module greater than the Filter Bandwidth setting is
filtered-out, and not sent to the drive.
If the Low-pass Output Filter Bandwidth value is set to zero, the low-pass
output filter is disabled. The lower the Filter Bandwidth value, the greater the
attenuation of these high frequency components of the output signal. Because
the low-pass filter adds lag to the servo loop, which pushes the system towards
instability, decreasing the Filter Bandwidth value usually requires lowering the
Position or Velocity Proportional Gain settings to maintain stability. The
output filter is particularly useful in high inertia applications where resonance
behavior can severely restrict the maximum bandwidth capability of the servo
loop.