Continuous motion, where the position changes between parameter 3-06 Minimum Position and pa-
rameter 3-07 Maximum Position. When passing the maximum position, the reading restarts from the
minimum position.
Parameter 17-77 Position Feedback Mode
Table 948: Parameter 17-77 Position Feedback Mode
17-77 Position Feedback Mode
Default value: [0] Relative
Change during operation: False
N O T I C E
This parameter is only available with software version 48.20.
Select the mode for handling absolute encoders. Select [0] Relative if the application requires tracking the position when the posi-
tion value exceeds the measuring range of the encoder, for example, when using single-turn encoders for linear motion. Select [1]
Absolute if the position values are always within the measuring range of the encoder, for example, when using a laser distance-
measuring device.
The actual position is set to the absolute position read from the encoder at power-up, and then the drive uses
only the position changes for calculating the actual position. In this mode, the actual position values are be-
tween -2147483648 and 2147483647 even when the values exceed the measuring range of the encoder. To
save and use the absolute position values outside the measuring range of the encoder after power-down, set
parameter 17-75 Position Recovery at Power-up to [1] On. The position value is accurate if the encoder does not
move by more than half of the encoder measuring range when the drive is powered down.
The drive uses the absolute position from the encoder as actual position continuously. In this mode, the actual
position values are between 0 and the maximum position of the encoder. The maximum position is determined
by the number of bits, for example, the SSI encoder has 25 bits and its maximum value is 2
25
= 33554432. Set
parameter 3-07 Maximum Position to the maximum value of the encoder scaled according to parameter 7-94
Position PI Feedback Scale Numerator, parameter 7-95 Position PI Feedback Scale Denominator, parameter 17-72
Position Unit Numerator, and parameter 17-73 Position Unit Denominator. If the position exceeds the measuring
range of the encoder, the absolute position reference is lost. For example, use this option if there is a laser dis-
tance-measuring device and there is a risk that some external objects may occasionally interfere with the laser
beam. In this case, the absolute positioning will work correctly when the external disturbance disappears.
Parameter 17-78 Active Position Counter
Table 949: Parameter 17-78 Active Position Counter
17-78 Active Position Counter
Default value: [0] Counter 0
Change during operation: False
The drive has 4 individual position counters. Only the selected counter is updated. Allows tracking position of up to 4 motors con-
trolled by 1 drive, 1 motor at a time. The active counter can be selected by this parameter in the same setup or by setup change
when selecting between motors.
AU275636650261en-000101 / 130R0334528 | Danfoss A/S © 2022.12
Parameter Descriptions
VLT AutomationDrive FC 301/302
Programming Guide
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