Delta Tau Geo MACRO, Руководство пользователя и справочное руководство

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Geo MACRO Drive User and Reference Manual
Setting Up Primary Feedback 73
Phase Clock frequency of the PMAC set by I7m00 and I7m01. The user has the ability to select the
excitation frequency to be equal with the Phase Clock frequency (default) by setting
MS<node>,MI932
equal to 0. Or use lower frequencies by increasing the value of MI932.
• Excitation frequency could be set equal to a half (1/2) the Phase Clock Frequency if MI932=1
• Excitation frequency could be set equal to a quarter (1/4) the Phase Clock Frequency if MI932=2
• Excitation frequency could be set equal to a sixth (1/6) the Phase Clock Frequency if MI932=3,
this would be and the lowest available excitation frequency.
Also the user needs to set the Excitation output gain for the systems resolvers, by setting
MS<node>,MI940 . Default MI940 is set to 0, which means a 2.5V gain peak-to-peak. If a gain of 5V
peak-to-peak is needed then the user needs to set MI940=1. With MI940=2 the output gain is 7.5V, and
the maximum gain would be 10V peak-to-peak when MI940=3.
Finally the resolver excitation phase time offset,
MS<node>, MI941 , needs to be set. The optimum
setting f MI941 depends on the L/R time constant of the resolver circuit. So MI941 should be set
interactively to maximize the magnitudes of the feedback ADC values. Turbo PMAC setup handles these
calculations, the section below shows how someone can set it up manually.
Setting up the Phase Shift (MI941) Manually
Set up the MS<node>, MI101 or MS<node>MI102 equal to 12 ($C) or 13 ($D) depending if it was $4 or
$5 respectively (basically add +8 to the value of MI101 or MI102). This decode value puts the ADC
values of the Sine and Cosine into the ADC registers of the corresponding IO node register.
For example, if using a resolver for motor #1 on Node 0:
MS0,MI101
5
MS0,MI101=13
This would enable the ADCs of the first resolver to come back on X:$78421 and X:$78422. (Check
Appendix D, ADC Registers Table.)
Now, setup two M-variables to point to these registers:
M905->X:$78421,8,16,s and M906->X:$78422,8,16,s were used in the example.
The values of these registers will toggle between a + and - value, sign does not matter; only the absolute
value is important. As the motor shaft is rotated, observe these values, if either of them is saturated to +/-
32767, the resolver gain is too high (MI940). Decrease its value.
Next, position the motor shaft so that one of the ADC values is close to the maximum value that can be
monitored. The other register will be close to 0.
MI941 default value is 0, start increasing its (MI941) value by increments of 25. The value of the large
ADC should slowly start increasing. If it decreases, start with MI941=255 and slowly start decreasing it
in increments of 25. The ADC value should increase up to a maximum point and then start to decrease
again. This point to the MI941 value that should be set to get the maximum ADC value possible.
Finally, if the maximum value of the large ADC is less than 16000, increase the gain of the resolver
(MI940).
Setting up the Resolver for Power-On Absolute Position
It is possible to get absolute position directly to the Geo drive. Most commonly, this is just the absolute
position within one motor revolution or even one commutation cycle to establish the commutation phase
reference position without any motion. This section summarizes the variable settings for this technique;
refer to the Appendix B or to the Software Reference Manual for details.