Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX User Manual

Page 166

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Applications

This can be verified by resetting the drive or cycling power to clear
the encoder position feedback parameters #227 & #228. Rotate the
shaft one revolution and observe the value of parameter #227. This
should be four times greater than the value of the encoder PPR
parameter #8.

Step Rotation Distance In Motor Shaft Revolutions

To define all encoder Step Value parameter units as graduated in
whole revolutions, set the Count Per Unit parameter (CPU) equal to 4
x the PPR parameter #8.

For Example: For a single revolution in a drive with a 1024 PPR
encoder;

CPU (P245) = 4 x 1024 (P8) = 4096

With the CPU parameter set, entering a value of 100 in the Step 1
Value
parameter #250, will cause the profile control to command the
Step 1 Speed until the motor has turned 100 revolutions.

P249 Step 1 Speed = 1726
P250 Step 1 Value = 100.0 units (revs)
P251 Step 1 Type = 3 (Encoder)

To have one encoder unit equal two motor revolutions:

CPU (P245) = 2 revs x (4 PPR) = 8 x PPR (P8)

To have one value parameter unit equal 1/2 revolution;

CPU (P245) = 1/2 x (4 PPR(P8)) = 2 x PPR (P8)

Step Value parameters can be entered in 1/10th unit increments.

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