HEIDENHAIN PWM 20 - Manual (Page 186)

November 2014 Checking incremental encoders 189
The image below shows an incomplete X-Y signal (segment):
Signal calculation is faulty; a is output; the bar graphs are not refreshed or faulty.
Note
For an exact calculation of the signal amplitudes and tolerances, the graphics must show a
full circle (360° sine/cosine curve). Usually, encoders can only be checked exactly, if they are
driven steadily. (A cordless screwdriver may be helpful. Observe the notes!)