Shorter-Path Traverse Of Rotary Axes: M126 - HEIDENHAIN TNC 620 User Manual

Multiple-axis machining | Miscellaneous functions for rotary axes

Shorter-path traverse of rotary axes: M126

Standard behavior
Refer to your machine manual.
The positioning behavior of rotary axes is machine-
dependent.
M126 has an effect only on modulo axes.
In the case of modulo axes, the axis position begins
again at 0° after the modulo length of 0° to 360° has
been exceeded. This is the case for rotary axes that are
mechanically capable of endless rotation.
In the case of non-modulo axes, the maximum rotation
is mechanically limited. The position display of the rotary
axis does not switch back to the starting value (e.g.,
0° to 540°).
The machine parameter shortestDistance (no. 300401) defines the
standard behavior for the positioning of rotary axes. It is effective
only for rotary axes whose position display is limited to a range
of traverse of less than 360°. If the parameter is inactive, then the
control traverses the programmed value from the actual position
to the nominal position. If the parameter is active, then the control
moves to the nominal position on the shortest path (even without
M126).
Behavior without M126:
Without M126, the control moves a rotary axis whose position
display is reduced to less than 360° along a long path.
Examples:
Actual position Target position
350° 10°
10° 340°
Behavior with M126
With M126, the control moves a rotary axis whose position display is
reduced to less than 360° on the shortest path of traverse.
Examples:
Actual position Target position
350° 10°
10° 340°
Effect
M126 takes effect at the start of the block.
M127 and a program end reset M126.
HEIDENHAIN | TNC 620 | Klartext Programming User's Manual | 01/2022
Traverse distance
–340°
+330°
Traverse distance
+20°
–30°
11
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