HEIDENHAIN TNC 320 (340 55x-03) - Manual (Page 51)

HEIDENHAIN TNC 320 51
2.3 Spindle Speed S
, F
eed Rat
e
F and Miscellaneous F
unctions M
Changing the spindle speed and feed rate
With the override knobs you can vary the spindle speed S and feed
rate F from 0% to 150% of the set value.
The override knob for spindle speed is only functional on
machines with infinitely variable spindle drive.