Limits of TRC

For the calculation of intermediate blocks, the TRC takes into account the actual and two further relevant NC-blocks. "Relevant" means, traverse blocks in the chosen main plane in which the tool radius compensation takes place. "Non-relevant" would be for instance, techno-blocks, time delays (G04) or traverse movements with one axis perpendicular to the main plane. If within these three blocks an intermediate block is calculated, which would run in a direction contrary to the programmed profile, then thereby a contour violation is recognized. In Fig. 12.24 an example in this context is demonstrated.

If a bottleneck position is caused through one or more blocks, which are farther than 3 blocks away from actual block, then, this contour violation is not recognized by the TRC. For this case, an illustration is given in Fig. 12.25.