Lenze PLC Designer PLC-Designer (R2-x) SoftMotion - Manual (Page 69)

DMS 5.2 EN 03/2011 TD17
L
69
L-force | PLC Designer - SoftMotion
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Supported and extended elements of the CNC language of DIN66025
4.1.4 Circular interpolation
The target coordinates (X/Y) need to be defined in order to describe a circular arc. There are
two ways of defining the circular curve: enter either the radius (R) of the circular arc or its
centre point coordinates (I/J).
If you enter the radius, please note that only arcs spanning fewer than 180° (semicircles)
are possible, since this method (except in the case of semicircles) always describes two
possible solutions - one greater than and one less than a semicircle. The system always
selects the solution less than a semicircle.
Example of a semicircle:
If you require a semicircle with an opening angle in excess of 180°, you need to define it via
(I/J). This method is unique, except in cases where the start and end points of the circle are
identical. In such cases this could result in a zero circle or a full circle; the system will insert
a full circle.
Please also note that where the method using (I/J) is concerned, it is of crucial importance
whether the coordinates I/J (see G98/G99) are entered as relative or absolute values. If I
and J are not entered correctly (distance between centre point and start/end point must be
identical), it will not be possible to create a circular arc and the system will insert a straight
line instead.
Example of the same semicircle specified by means of a relative centre point:
Example of the same semicircle specified by means of an absolute centre point:
N10 G1 X100 Y100
N20 G2 X200 Y100 R50
N10 G1 X100 Y100
N15 G99
N20 G2 X200 Y100 I50 J0
N10 G1 X100 Y100
N15 G98
N20 G2 X200 Y100 I150 J100