HEIDENHAIN PWM 20 - Manual (Page 168)

November 2014 Checking incremental encoders 171
The image below shows the record of a linear encoder without error.
The diagrams can be zoomed and the blue areas shifted to view the results in detail.
Note
If the output signals are faultless, the curves in the middle and lower display fields
(2 and 3) are almost congruent, and there are no fluctuations beyond the tolerance limits.
In the display field 1, "neckings" should be visible.