# ID 90038

Compensation motion within circular motion block in tool radius compensation.
Description | To detect contour violations in circular blocks, the corrected circular angle is compared with the original programmed angle. If the corrected circular angle is greater than the programmed one, the contour will be damaged. This is referred to as the compensation motion.

The figure above shows that if the direction of rotation is maintained at N20', the equidistant arc would damage the contour.

This may be caused by a relatively small motion block, e.g. smaller than the tool radius. This leads to contour violations when calculating the equidistant path.

When using contour masking with G141, this error is not output because the closed contour loop is deleted. In the figure above, this would remove the circular motion of N20' and thus no contour damage would occur.

[PROG// Section : Limits of TRC]

Response | Class | 2 | Abort NC program processing.
Solution | Class | 6 | Possible solutions are:

- Use a tool with smaller radius
- Use contour masking (G141)

Parameter | %1: | Current value [0.1 µm or 0.0001°]
Corrected circular angle
%2: | Upper limit value [0.1 µm or 0.0001°]
Maximum permissible circular angle
Error type | 1, Error message from NC program.