Mitsubishi Electric MELSEC-L LD75P User Manual page 405

When "0: Composite speed" is set in "[Pr.20] Interpolation speed designation method", the command speed of ABS3/INC3 is
the same as the composite speed of the 3 axes (x axis - y axis - z axis). The command speed of 3-axis helical interpolation
control is the same as the composite speed of the circular interpolation axis (x axis - y axis). When continuous path control is
carried out in ABS3/INC3 and 3-axis helical interpolation control, adjust the command speed to prevent the workpiece from
moving unsteadily because the workpiece movement speed may change when positioning data is switched.
(2) Rotation angle of the circular interpolation axis (X axis - Y axis)
The following shows the rotation angle of the circular interpolation axis in 3-axis helical interpolation control.
Y axis
θ
Number of pitch
0
1
2
to
n
to
999
A true circle can be set only when the start point equals to the end point in 3-axis helical interpolation (ABS/INC,
center point).
When "degree" is set for the unit setting in the absolute system, the positioning range is 0 to 359.99999. When the axis
rotates 360 or more in circular interpolation control (x axis - y axis), the tangential/normal control cannot be carried out
because a degree of 360 or more cannot be set in linear control (z axis: degree). To carry out tangential/normal control in
which the axis rotates 360 or more, use 3-axis helical interpolation control (INC).
(3) Rotation direction when the unit for the linear axis (z axis) is degree
When "[Pr.1] Unit setting" for the linear axis is "degree", the rotation direction is determined according to the axis
control data "[Cd.40] ABS direction in degrees" of the reference axis. To set the rotation direction for each
positioning data, set the position data "[Da.28] ABS direction in degrees".
End point
Start point
X axis

360 + 
720 + 
to
360  n + 
to
360  999 + 
CHAPTER 9 MAJOR POSITIONING CONTROL
Circular interpolation axis control
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