Yaskawa MP2000 Series: User's Manual for Motion Programming - Manual (Page 348)

App
D Precautions
A-27
(4) Do not change the motion setting parameter OL 1C “Position reference setting”
while axis motion is in progress in a motion program.
If OL 1C “Position reference setting” is changed in another program (e.g. a ladder program) while axis
motion is in progress in a motion program, the axes will move in accordance with the change. This will result in
a discrepancy between the actual position and the position specified in the motion program.
Example:
If the travel distance of the A1 axis specified by OL
1C “Position reference setting” in the motion program
below is changed from +1000 to +1500 while executing (a) in the motion program, the A1 axis moves to the
position +1500. At this point a discrepancy arises in relation to the reference position in the motion program
(+1000). Then (b) in the motion program will be executed. As a result, the actual final position of the A1 axis will
be at a different position from that specified in the motion program.
INC;
ZRN [A1]0;
MOV [A1]1000;
• • •
(a)
MOV [A1]1000;
• • •
(b)
END;
Actual position of
the axis
0 1000 1500 2000 2500
(a) (b)
(a) (b)
Discrepancy
in final
position
Position that the motion
program specifies
Change in
travel in the
ladder
program