HEIDENHAIN PWM 8 - Manual (Page 8)

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b): Measuring range and scaling of the PHA/TV display:
Definitions:
TV1, TV2 : On-to-off ratio incremental signal 1, incremental signal 2.
At the zero crossover analogue incremental signals are triggered, i.e. converted into square-wave signals.
One period (= on-time plus off-time of a square-wave signal) is subdivided into 360°.
If on-time and off-time of a square-wave signal are the same, i.e. 180° each (180° + 180° = 360°), the
on-to-off ratio is 0°. If the on-time of a square-wave signal exceeds the off-time, the on-to-off ratio is positive.
An on-to-off ratio of e.g. +10° means the on-time of the square-wave signal is 190° (180° + 10°) and the
off-time 170° (180° - 10°).
PHA: Phase angle error between incremental signal 1 and incremental signal 2.
If the incremental signal 1 leads the incremental signal 2 by 90°, the phase angle error is 0°. The phase
angle error is the deviation from the optimum phase shift of 90° dimensioned in degrees.
PHA/TV Display:
PHA and TV are displayed as bars. The scaling of the PHA/TV display can be set for different measuring
ranges.
With automatic switch-over of the measuring range the (graduated) range of the PHA/TV display is
automatically adapted to the biggest error (longest bar).
Measuring range of the PHA/TV display (here
±
25°)
With automatic switch-over of the measuring range the
longest bar defines the measuring range.
Symbol for automatic switch-over of the measuring range.
Error display for: on-to-off ratio incremental signal 1 (TV1),
on-to-off ratio incremental signal 2 (TV2), phase angle error
between the two incremental signals (PHA)
If the measuring range is exceeded with manual switch-over of the measuring range, an
error is displayed. Switching over the measuring range: see standard soft-key row in section 3.2
Measuring range exceeded in negative direction
Measuring range exceeded in positive direction
Manual switch-over of the measuring range