February 2012 19 – 291
The A and B signals must be of equal size and move symmetrically about the same vertical axis
(no vertical offset)!
The 90° offset of the signals A and B on the horizontal axis is clearly visible.
A drop of the amplitudes during traverse could e.g. be an indicator of a contaminated scale section.
If the amplitude is too low in standstill, the scanning head may be contaminated.
The signals in the integrated oscilloscope are always displayed in mV, irrespective of the type of
encoder connected (1 Vpp or 11 µApp).
8 Check whether the sinusoidal signals have an offset (2.5 V).
You will also find that the sinusoidal signals do not correspond to 1 Vpp or 11 µApp.
In this case, the signals must be converted according to special formulas:
8 Now you can switch the oscilloscope display to XY(Lissajous figure):
Current signal
11 µApp
Oscilloscope display [mV] / 284 = encoder signal at input [µA]
e.g.: 3124 [mV] / 284 = 11 [µA]
Voltage signal
1 Vpp
Oscilloscope display [mV] / 3480 = encoder signal at input [V]
e.g.: 3480 [mV] / 3480 = 1 [V]
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