Drive control and features60With absolute encoders and resolvers, there is often a need to change the positioncalculation zero permanently without physically rotating the motor. This is possibleby using parameter 62.20 POS ACT OFFSET. The value of the parameter is addedto the position feedback value. The offset can be made permanent after the homingprocedure using parameter 62.21 POS COR MODE.Position estimationWith synchronous motors, the drive also supports positioning without a speed andposition feedback device. In position estimation, the actual position of the drive (1.12POS ACT) is calculated using the estimated speed as the position change betweenthe current time and the last known position. The accuracy of this position estimatedepends heavily on the motor model accuracy. The different types of positionscaling, the drive position system range and the hardware limits are the same as forposition calculation.Position estimation can be selected as the position feedback value for the positioncontroller via parameter 60.01 POS ACT SEL. In addition, at least one latch signalmust be available in the revolution to correct the actual position of the drive.
