6.18 Online Compensation (Offset and Amplitude Control)
Contamination and mounting errors lead to interferences in the optical scanning of the scale by the
scanning head and so to periodic deformations of the sinusoidal counting track signals, which are
exemplified as
•
Offset deviations
• Amplitude deviations
•
Amplitude differences between the sine and cosine channels
and lead to interpolation errors�
U
sin
+ U
cos
U
sin
/U
cos
U
sin
+ U
cos
U
sin
/U
cos
U
sin
/U
cos
U
sin
+ U
cos
Contaminated Scale Tape
Scanning head signal with contaminated
grating disk before activation of the online
compensation�
Incorrect Mounting
Scanning head signal with faulty
mounting before activation of the online
compensation�
Active Online Compensation
Scanning head signal with contaminated
grating disk and/or faulty mounting after
activation of the online compensation�
U
sin
+ U
cos
U
sin
/U
cos
U
sin
+ U
cos
U
sin
/U
cos
U
sin
/U
cos
U
sin
+ U
cos
U
sin
+ U
cos
U
sin
/U
cos
U
sin
+ U
cos
U
sin
/U
cos
U
sin
/U
cos
U
sin
+ U
cos
Through the offset and amplitude control the signals generated by the measuring module are
automatically corrected within the sensor without following error over the entire velocity range�
This measure not only increases the accuracy, but also the reliability of the encoder�
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KIT
L
-Series