How STOP Events work

Resuming Motion after STOP Events

When a motion supervisor sees a STOP event (generated by anything in the domains of motion supervisor's axes), the Feedrate is changed from NormalFeedrate to PauseFeedrate (MS[n].PauseFeedrate in the firmware). To set the PauseFeedrate or NormalFeedrate , use the method mpiMotionConfigSet(...). See sample code below:

/* Modify normal and pause feedrate values */

void modifyFeedrate(MPIMotion  motion,
                    float      normalFeedrate,
                    float      pauseFeedrate)
   {
      MPIMotionConfig motionConfig;
      long   returnValue;

    /* Get Motion Supervisor existing configurations */

     returnValue = mpiMotionConfigGet(motion,
                                      &motionConfig,
                                      NULL);
     msgCHECK(returnValue);

    /* Modify normal and pause feedrate values */

     motionConfig.normalFeedrate = normalFeedrate;
     motionConfig.pauseFeedrate  = pauseFeedrate;

    /* Set the values in Motion Supervisor Configuration */

     returnValue = mpiMotionConfigSet(motion,
                                      &motionConfig,
                                      NULL);
     msgCHECK(returnValue);

}

How quickly the NormalFeedrate changes to PauseFeedrate is determined by the value of StartStopRate (which is set by motionConfig.decelTime.stop). Normally, PauseFeedrate is 0.0, which causes the motion to stop.

When the motion is re-started (using mpiMotionAction(...,MPIActionRESUME) for STOP events), the Feedrate is changed back to the NormalFeedrate at the StartStopRate rate.

Note that STOP events are latched by the firmware, while PAUSE events aren't. This means that if you configure a user limit to trigger a STOP event when an input (like Xcvr) is set (= 1), the Motion will go from NormalFeedrate to PauseFeedrate when that bit is set, and the Motion will stay at the PauseFeedrate until mpiMotionAction(...,MPIActionRESUME) is called.

If a limit is configured for a PAUSE event, the Motion will resume automatically after the bit is cleared (mpiMotionAction(...,MPIActionRESUME) is not needed).