User Units View - Emerson EZMotion User Manual

(increasing absolute position).
CCW Motor Rotation Radio Button
Select this radio button for applications in which CCW motor rotation is considered to be motion in the positive direction (increasing
absolute position).
Dual Loop Group
Dual Loop Control Mode Enable Check Box
Select this check box to enable the Dual Loop Mode feature which accepts a secondary feedback device to close the position loop
while still using the motor encoder to close the velocity loop.
Position Feedback Source
This list box is used to define the physical connection location of the Position Feedback Encoder to the Unidrive SP/Digitax ST
system. This is different from the Motor Feedback Source.
Position Feedback Polarity
This list box is used to define which direction the Position Feedback Encoder counts when the feedback device moves in the
"positive" direction. Positive = Counts Up, Negative = Counts Down.
Dual Loop Encoder Ratio
Motor Enc Revs
This parameter is the numerator in the ratio used to define the mechanical ratio between the Motor Encoder and the Position
Feedback Encoder. This parameter is only used when Dual Loop Control Mode is enabled, and must be set correctly to achieve the
correct target velocity.
Posn Fdbk Enc Revs
This parameter is the denominator in the ratio used to define the mechanical ratio between the Motor Encoder and the Position
Feedback Encoder. This parameter is only used when Dual Loop Control Mode is enabled, and must be set correctly to achieve the
correct target velocity.
8.4.2

User Units View

The User Units view allows the user to configure the distance, velocity, and acceleration units to be used for the motor axis
throughout the application. Figure 81 shows an example of the User Units View.
Figure 81:
Distance
Units Name
This is a 10 character name for the distance user units you want to use in your application.
Decimal Places
The number of decimal places set in this parameter determines the number of digits after the decimal point used in all distance and
position parameters throughout the software. Using a high number of decimal places will improve position resolution, but will also
limit the range of absolute position. You can select from zero to six decimal places of accuracy.
Scaling
A Characteristic Distance and Length must be established to allow the module to scale user units back to actual motor revolutions.
76
User Units View
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EZMotion User/Programming Guide
Revision: A8