HEIDENHAIN PWM 20 - Manual (Page 175)

178 HEIDENHAIN ATS Software User's Manual
Working with the table and the graphics
The table and the graphics are used to check the counting function over several reference marks
(RM).
 For analog encoders, signal periods are displayed (values are not interpolated).
 The counter value is determined by traversing two reference marks.
 In the table, the direction is symbolized by double-headed arrows (>>; <<).
 In the Y axis the graphics shows the counted signal periods and in the X axis the number
of traversed reference marks.
With rotary encoders, the signal periods (= the line count) are counted when you turn the
shaft continuously. With encoders with TTL signals and integrated interpolation electronics
(e.g. TTL x 5), the line count is multiplied with the interpolation factor (e.g. 1000 lines on the
graduated disk, interpolation factor x 5 = display value 5000).
With linear encoders with one reference mark, the counter starts when the RM is traversed and
it must show the value zero (0) every time the RM is traversed again. In this case the entries in
the table and the graphics are "0".
For distance-coded RM the distance coding is displayed.
Example:
Checking a rotary encoder with 1000 lines in both directions (red square)
Viewing the encoder shaft, make a few revolutions - clockwise and counter-clockwise
(>> and <<).
The value displayed for Reference must be the same as the line count of the encoder, even at
high scanning frequencies. Otherwise, the encoder is faulty. (Even a difference of only
signal
period is not tolerable!)
Note
Check both directions of rotation (traversing directions)! Observe the cutoff frequency of the
encoder, and do not exceed the mechanically permissible speed (ball bearings could be
destroyed)!
1
