The control uses these functions to approach a contour on a circular path with tangential connection and a straight line. You use APPR LCT to define the starting point of the contour with Cartesian coordinates, and APPR PLCT for polar coordinates.
Application
Description of function

- The control approaches the contour as follows:
- On a straight line from the starting point PS to an auxiliary point PH
- On a circular path in the working plane from the auxiliary point PH to the first contour point PA
If you program the Z coordinate in the approach block, the control simultaneously moves the tool from the starting point PS to the auxiliary point PH.
The circular path is connected tangentially both to the line PS to PH as well as to the first contour element. Once this information is entered, the radius R suffices to unambiguously define the tool path.
The feed rate programmed in the approach block is effective for the entire path that the control traverses in the approach block. If no feed rate is programmed before the approach block, the control generates an error message.
Programming APPR LCT and APPR PLCT
If you want to program this path shape with polar coordinates, then you must first define a pole CC.
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Example APPR LCT
11 L X+40 Y+10 R0 FMAX M3 | ; Approach PS without radius compensation |
12 APPR LCT X+10 Y+20 Z-10 R10 RR F100 | ; PA with radius compensation RR, radius of the circular path: R 10 |
13 L X+20 Y+35 | ; End point of first contour element |
14 L ... | ; Next contour element |