169
User Defined Motors
Where:
EMA = Motor Encoder Marker Angle
If EMA is >360° subtract 360°.
Many encoders are designed so that the encoder marker pulse occurs a specified number of
electrical degrees from the rising edge of U. You could obtain this value from the encoder
specification sheet however, to minimize errors in conversion, you should make this
measurement.
If you cannot obtain a stable angle measurement between U or Z and V
TS
, check the encoder
to verify it has the proper cycles per revolution for your motors pole count.
CW Reference Rotation
If the reference motion for the encoder is CW (i.e., Encoder Reference Motion parameter will
be set to 1), rotate the motor in the CW direction. Using an oscilloscope, look at the phase
relationship between the rising edge of U and negative peak of V
TS
. Use the figure below to
determine the electrical angle at the rising edge of U. Determine the marker electrical angle
in a similar manner.
÷
ø
ö
ç
è
æ
+
°
=
t1
180
tz
90
EMA
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