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MPIMotionPoint

Definition

typedef struct MPIMotionPoint {
    MPI_BOOL  retain;     /* FALSE => flush points after use */
    MPI_BOOL  final;      /* FALSE => more points to come */
    long      emptyCount; /* # of remaining points to trigger
                          empty event, -1 => disable */
} MPIMotionPoint;
 

Change History: Modified in the 03.03.00

Description

 
retain This value specifies whether or not the points should be stored in a buffer after execution. If retain=0, the points will not be stored after execution. If retain=1, the points will be stored in a buffer. This feature is useful for backing up on path.
final This value specifies if more points will be loaded. If final=1, no more points will be loaded. If final=0, more points can be loaded using mpiMotionModify(...) with the MPIMotionAttrMaskAPPEND attribute mask.
emptyCount This value specifies the minimum number of points in the controller's buffer to trigger an E_STOP action and a MOTION_OUT_OF_FRAMES event.

If ALL the points for a move fit into the controller's buffer, the emptyCount can be disabled with a value of 0.

If ALL the points for a move do NOT fit into the controller's buffer, you must set the emptyCount to a non-zero value. Any points that do not fit into the controller's buffer will be streamed from the host to the controller via the eventMgr. The controller monitors the emptyCount to determine if it will run out of points. If the number of frames left in the controller's buffer is less than the emptyCount, an E_STOP action will occur for all axes mapped to the Motion Supervisor. An E_STOP will decelerate the axes to a stop along the path of the controller's remaining points. The emptyCount must be set to a large enough value to allow the E_STOP to stop motion BEFORE the end of the point list is reached. For example, if each point takes 5 milliseconds to execute and an E_STOP is configured for 20 milliseconds, then emptyCount should be 4 (or higher).

The valid range is 0 to the controller's axis frame buffer size.

See Also

mpiMotionModify | MPIMotionAttrMaskAPPEND | MPIMotionPT

 

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