HEIDENHAIN iTNC 530 User Manual page 370

You cannot use the following global program run settings
if you have used the M91/M92 function (moving to machine-
referenced positions) in your NC program:
Swap axes in the axes in which you approach machine-
based positions
Locking axes
You can use the look-ahead function M120 if you have
activated the global program settings before starting the
program. If M120 is active and you change global settings
during the program, the TNC will show an error message
and stop any further machining.
If DCM collision monitoring is active you can only move
with handwheel superimposition if you have interrupted
the machining program with an external stop.
In the fillable form the TNC grays out any axes that are not
active on your machine.
Shift values and values for handwheel superimposition in
the fillable form must always be defined in millimeters;
angle values for rotations must be defined in degrees.
370 Programming: Special Functions