ABB ACS880 - Page 571

Def / Type
FbEq 16b / 32b
DescriptionName / Range /
Selection
No.
24 / uint16Defines how many bits are used for motor position
count within one revolution. For example, with the
setting of 24, the position value is multiplied by
16777216 for display in parameter 90.6 Motor position
scaled (or for fieldbus).
Motor position
resolution
90.49
- / -Motor position resolution.0...31
None / uint16Selects the source of load speed and position
feedbacks used in control.
Load feedback
selection
90.51
0No load feedback selected.None
1Load feedbacks are updated based on the speed and
position values read from encoder 1.
The values are scaled by the load gear function (90.53
Load gear numerator and 90.54 Load gear
denominator).
The encoder is set up by the parameters in group 92
Encoder 1 configuration.
Encoder 1
2Load feedbacks are updated based on the speed and
position values read from encoder 2.
The values are scaled by the load gear function (90.53
Load gear numerator and 90.54 Load gear
denominator).
The encoder is set up by the parameters in group 93
Encoder 2 configuration.
Encoder 2
3Calculated speed and position estimates are used. The
values are scaled from the motor side to the load side
using the inverted ratio between 90.61 Gear numerator
and 90.62 Gear denominator (ie. 90.62 divided by 90.61).
Estimate
4The source selected by parameter 90.41 Motor feedback
selection for motor feedback is also used for load
feedback.
Any difference between the motor and load speeds
(and positions) can be compensated by using the
inverted ratio between 90.61 Gear numerator and 90.62
Gear denominator (ie. 90.62 divided by 90.61).
Motor feedback
4 ms / real32Defines a filter time for load speed feedback (90.3 Load
speed).
Load speed filter
time
90.52
- / -Load speed filter time.0...10000 ms
1 / int32Parameters 90.53 and 90.54 define a gear function
between the load (ie. driven equipment) speed and the
encoder feedback selected by parameter 90.51 Load
feedback selection. The gear can be used to correct a
difference between the load and encoder speeds for
example if the encoder is not mounted directly on the
rotated machinery.
90.53
90.54
=
Load speed
Encoder speed
See also section Load and motor feedback (page 93).
Note: This parameter cannot be changed while the
drive is running.
Load gear
numerator
90.53
Parameters 571