Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 98)

98 Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
Position Reference Scaling
Position reference can be entered in user units by using the EGR scaling.
Parameters 745 [PositRef EGR Mul] and 746 [PositRef EGR Div] are used to
scale the position reference.
Example:
To use degrees of motor revolution for the positioning units, scale as follows:
With a 1024 encoder on the motor, this translates to 4096 counts per
revolution quadrature position counts.
This scaling translates the position reference of 0…360 degrees to 0…4096
position counts. This will allow you to enter degrees of motor rotation for
the position reference.
Position Offset
Offsets can be added to the position reference. Offset are used to make a
correction move to synchronize the follower to the master position.
There are two offsets, parameters 753 [Posit Offset 1] and 754 [Posit Offset 2].
The offset speed must be entered in parameter 755 [Posit Offset Spd] - if this is
left at zero the move will not occur. The position offset must be entered in counts
Parameter 745 [PositRef EGR Mul] = 4096
Parameter 746 [PositRef EGR Div] = 360
Gear Rat
[ N ]
[ D ]
745
746
PositRef EGR Mul
PositRef EGR Div
744 PositRef EGR Out
Geared Position
Reference Selected Position
Reference
Deriv
Δ
+
Rate Lim
753
754
755 LPass
Filter
756
Posit Offset 1
Added to Position
Reference After EGR
Posit Offset 2
Posit Offset Spd
Position Control
(X Offset Pol)
Position Control
(X Offset Ref)
Deriv
Δ
740 04
740 05
741 05
Position Status
(XOffRRef Act)
X Offst SpdFilt