G12.1: Polar Coordinate Interpolation Mode Start - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

G12.1: Polar coordinate interpolation mode start

Starts polar coordinate interpolation mode which transforms linear axis movement (tool movement) and rotating axis
movement (work rotation) for contouring control.
This is effective when cutting out a linear notch from the outer diameter of a workpiece, grinding a camshaft etc.
Code Format
G12.1
G12.1
Processing details
• The G12.1 command performs polar coordinate interpolation on a selected polar coordinate interpolation plane which uses
the linear axis as the first axis of the plane and a perpendicular virtual axis (polar coordinate interpolation rotating axis) as
the second axis of the plane. In polar coordinate interpolation, the home position of the local coordinate system is the home
position.
Linear axis
X
Rotating axis
(virtual axis)
• The G12.1 command is modal. Polar coordinate interpolation mode continues until polar coordinate interpolation mode
cancel (G13.1) is commanded.
• Use the G12.1 command in an independent block. When other commands are used in the same block, a minor error (error
code: 1FC3H (details code: 0306H or 0324H)) occurs. Note that sequence No. (N), and speed (F, ,F) can be specified in
the same block.
• Set linear axis and rotating axis for polar coordinate interpolation in [Motion Control Parameter][G-code Control
Parameter][G-code Control System Parameter]"Polar Coordinate Interpolation""Polar Coordinate Interpolation Linear
Axis" or "Polar Coordinate Interpolation Rotating Axis". When G12.1 is commanded without setting "Polar Coordinate
Interpolation Linear Axis" or "Polar Coordinate Interpolation Rotating Axis", a minor error (error code: 1FC3H (details code:
0325H)) occurs.
• When transitioning to G-code control or resetting, polar coordinate interpolation is cancelled.
• Deceleration check is performed in a polar coordinate interpolation mode start command block (G12.1).
• During polar coordinate interpolation, the area which the linear axis can move is determined by the position of the linear
axis when polar coordinate interpolation is commanded. To use the plus side of the area which the linear axis can move
during polar coordinate interpolation, the linear axis must be moving in the plus area (0 or more) before polar coordinate
interpolation is commanded. Conversely, to use the minus side of the area which the linear axis can move, the linear axis
must be moving in the minus area (not including 0) before polar coordinate interpolation is commanded.
Plus side area
Plus side
Virtual C
θ
Virtual X
Polar coordinate interpolation plane (G17 plane)
C
Z
Linear axis
Minus side area
Minus side
Virtual X
-θ
Virtual C
5 G-CODE CONTROL PROGRAMS
Linear axis
5.6 G-Code
5
115