HEIDENHAIN PWM 20 - Manual (Page 152)

November 2014 Checking incremental encoders 155
Filter (100 kHz)
Help circle
Filter button (100 kHz)
Press this button to damp the bandwidth of the input amplifier. Interfering signals
over 100 kHz are suppressed.
This function is used for special adjustments where interferences have a negative
effect on the adjustment procedure. In general, the filter function is inactive in
order that the full bandwidth of the PWM 20 can be used.
Filter inactive/off = Button is gray
Filter active = Button is blue
(Interfering) frequencies 100 kHz are suppressed.
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Help circle key
Pressing this key freezes the x-y signal circle on the oscilloscope (help circle); it
serves as a comparison for the current x-y signal.
Signal fluctuations of linear and angle encoders can thus be seen more clearly.
On the image, the outer circle is the active help circle (arrow).
Help circle function inactive = Button is gray
Display contains help circle = Active; button is blue