HEIDENHAIN ITNC 530 - CYCLE PROGRAMMING User Manual page 321

Characteristics common to all touch probe
cycles for measuring workpiece misalignment
For Cycles 400, 401 and 402 you can define through parameter Q307
Default setting for basic rotation whether the measurement
result is to be corrected by a known angle (see figure at right). This
enables you to measure the basic rotation against any straight line 1
of the workpiece and to establish the reference to the actual 0°
direction 2.
HEIDENHAIN iTNC 530 321