User`s manual

11-6 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
11
Torque Limiting Program Example
The following example illustrates a method to use local logic in concert with a motion program to
perform torque limiting based upon a block number within a motion program. In the example, the
servo axis 1 applies a nut on the threaded shaft. At the beginning the axis moves a little backward
to improve the nut and shaft threads engagement. This motion has the torque limit set to the
maximum value. Next the nut is twisted until tight with the torque limited to 30% of the maximum
value. During this operation the motion command destination point usually is not reached and the
axis stops when the load friction is greater then the torque limit. Subsequently, to release all tension
in the mechanics, the torque is set to 0 and after 0.1 second the signal “screw operation done” is
turned “on”. When the “nut gripper released” signal is turned on by the PLC the axis moves to the
initial position with the full torque.
Torque Limiting Local logic program.