Mitsubishi Electric RD77MS2 - Page 104

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3 MAJOR POSITIONING CONTROL
3.2 Setting the Positioning Data
• When the movement amount of the linear interpolation axis is more than the composite movement amount
of the circular interpolation axis, the speed of the linear interpolation axis cannot be suppressed with "[Pr.8]
Speed limit value".
• When "0: Composite speed" is set in "[Pr.20] Interpolation speed designation method" or "1: Composite
speed" is set in "[Da.29] Interpolation speed designation method", the command speed of ABS3/INC3 is the
composite speed of the three axes (X axisY axisZ axis). The command speed of the 3-axis helical
interpolation control is the composite speed of the two axes (X axisY axis). When the continuous path
control is performed using ABS3/INC3 and the 3-axis helical interpolation control, the movement speed of
the workpiece may change at the positioning data switching; therefore, adjust the command speed not to
shake the workpiece.
Rotation angle of circular interpolation axis (X axisY axis)
The rotation angle of the circular interpolation axis in the 3-axis helical interpolation control is as follows.
The setting of the true circle is available only when "Start point = End point" is set for the 3-axis helical interpolation (ABS/INC,
center point).
When "degree" is set to "[Pr.1] Unit setting", the positioning range of the absolute system is 0 to 359.99999. If
the rotation angle is 360 or larger in the circular interpolation axis (X axisY axis), the tangent control and
normal line control cannot be performed because 360 or larger angle cannot be set for "[Da.6] Positioning
address/movement amount" of the linear interpolation axis (Z axis: degree). To perform the tangent control or
normal line control with the rotation of 360 or larger angle, use the incremental system.
True circle Other than the true circle
Number of pitch Control of the circular interpolation axis
True circle Other than the true circle
0 360
1360 + 
2 720 720 + 

n 360  n360  n + 

999 360  999 360  999 + 
Y axis
 = 360°
Start point = End point
X axis
Y axis

X axis
End point
Start point