Lenze PLC Designer PLC-Designer (R2-x) SoftMotion - Manual (Page 279)

DMS 5.2 EN 03/2011 TD17
L
279
L-force | PLC Designer - SoftMotion
SoftMotion programming examples
Drive control with the aid of the CNC editor
– The mechanism behind this works as follows: Initially approximately one GEOINFO
object per cycle is generated within the slow task, which is saved in the OUTQUEUE
structure of the decoder block. If this OUTQUEUE is full, the blocks of the slow task
pause until the OUTQUEUE is no longer full, i. e. until the quick task has processed
the first GEOINFO object and deletes it from the OUTQUEUE. Then the blocks of the
slow task are reactivated and fill the OUTQUEUE structure. In the quick task one path
position from the OUTQUEUE structure which the input DataIn of the interpolator
points to is calculated and processed per cycle. As a GEOINFO object usually consists
of several path positions, it takes several cycles until the first GEOINFO object is
processed and is deleted automatically by the interpolator. As the processing of a
GEOINFO object obviously requires more cycles than the creation, the slow task
actually can be called less frequently that the quick one. However, the task times
have to be selected in a way that in the last OUTQUEUE of the slow task always a
sufficient number of GEOINFO objects is stored, so that there is no data underrun.
This occurs if no GEOINFO objects are provided to the interpolator from DataIn and
the path end has not yet been reached. In this case the interpolator brakes and
remains at standstill until new data elements are available again.
– In the Path program the decoding of the CNC program for OutQueue and the speed
check take place: