HEIDENHAIN iTNC 530 467
14.5 Datum Setting without a 3-D Touch Probe
Explanation of values saved in the preset table
 Simple machine with three axes without tilting device
The TNC saves in the preset table the distance from the workpiece 
datum to the reference point (with the correct algebraic sign).
 Machine with swivel head
The TNC saves in the preset table the distance from the workpiece 
datum to the reference point (with the correct algebraic sign).
 Machine with rotary table
The TNC saves in the preset table the distance from the workpiece 
datum to the center of the rotary table (with the correct algebraic 
sign).
 Machine with rotary table and swivel head
The TNC saves in the preset table the distance from the workpiece 
datum to the center of the rotary table.
Danger of collision!
Keep in mind that moving an indexing feature on your 
machine table (realized by changing the kinematics 
description) requires you to redefine any workpiece-based 
presets.