Fanuc Series 15i/150i-MA (Programming) Operators Manual

B-63324EN/03 PROGRAMMING 19.AXIS CONTROL FUNCTIONS
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19.7 ROTARY AXIS ROLL-OVER
The roll-over function prevents coordinates for the rotation axis from
overflowing.
The roll-over function is enabled by setting bit 2 of parameter RDA
1009 to 1.
When the rotation axis rollover function is used, the absolute
coordinates are rolled over by the amount of travel per rotation that is
set for parameter No. 1260.
Explanation
In the incremental mode, a specified value directly indicates an angular
displacement. In the absolute mode, the specified value is converted to
the remainder obtained by dividing the specified value by 360 degrees.
The difference between the converted value and the current value
indicates the angular displacement. The movement by angular
displacement is always made in the shorter direction. That is, if the
difference between the converted value and the current value is greater
than 180 degrees, the movement to the specified position is made in the
opposite direction. If the difference is 180 degrees, the movement is
Example
When the roll-over function is used for rotation axis A with the
rotation axis:
G90 A0 ;
Sequence
number
Actual
movement
value
Absolute
coordinate
value after
movement end
N1 G90 A-150.0 ; N1 -150 210
N2 G90 A540.0 ; N2 -30 180
N3 G90 A-620.0 ; N3 -80 100
N4 G91 A380.0 ; N4 +380 120
N5 G91 A-840.0 ; N5 -840 0
Fig.19.7 (a)
Relative
coordinate value
Absolute
coordinate value
-720°
-0°
-360°
-0° -0°
-0°
360°
-0°
N1
N2
N3
N4
N5
210° (Absolute)
180°
100°
120°