ABB ACS880-17 - Page 394

394 Parameters
Warning Drive generates an A798 Encoder option comm loss, A7B0
Motor speed feedback or A7E1 Encoder warning and
continues operation using estimated feedbacks.
Note: Before using this setting, test the stability of the speed
control loop with estimated feedback by running the drive on
estimated feedback (see 90.41 Motor feedback selection).
1
90.46 Force open loop Forces the DTC motor model to use estimated motor speed
as feedback. This parameter can be activated when the
encoder data is obviously unreliable because of slippage, for
example.
Note: This parameter only affects the selection of feedback
for the motor model, not for the speed controller.
No
No The motor model uses the feedback selected by 90.41 Motor
feedback selection.
0
Yes The motor model uses the calculated speed estimate
(regardless of the setting of 90.41 Motor feedback selection,
which in this case only selects the source of feedback for the
speed controller).
1
90.48 Motor position axis
mode
Selects the axis type for motor position measurement. Rollover
Linear Linear. 0
Rollover The value is between 0 and 1 revolutions, and rolls over at
360 degrees.
1
90.49 Motor position
resolution
Defines 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 90.06 Motor position scaled (or for fieldbus).
24
0…31 Motor position resolution. -
90.51 Load feedback
selection
Selects the source of load speed and position feedbacks used
in control.
None
None No load feedback selected. 0
Encoder 1 Load 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.
1
Encoder 2 Load 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.
2
Estimate Calculated 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).
3
Motor feedback The 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).
4
No. Name/Value Description Def/FbEq16