Lenze PLC Designer PLC-Designer (R2-x) SoftMotion - Manual (Page 209)

DMS 5.2 EN 03/2011 TD17
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209
L-force | PLC Designer - SoftMotion
The SM_CNC.lib library
Structures of SM_CNC.lib
Structure initialisation
The SMC_NCDecoder, SMC_SmoothPath, SMC_RoundPath, SMC_AvoidLoop and
SMC_ToolCorr SoftMotion program organisation units, which provide a pointer to an
internally managed OutQueue structure, will automatically initialise the structure. The
SMC_SmoothPath, SMC_RoundPath, SMC_ToolCorr, SMC_AvoidLoop and
SMC_Interpolator program organisation units need a pointer to a correct OutQueue list in
the form of an input. If this list is programmed and filled "manually", correct initialisation
also needs to be performed manually. The first two variables (buffer, size) must be set. It is
also strongly recommended that the above functions are used when working with an
SMC_OUTQUEUE and that, if at all possible, the other variables are not modified following
initialisation.
Structure components
pbyBuffer: POINTER TO BYTE
This variable contains the address of a coherent memory area, which is allocated for saving
GEOINFO objects. This memory must be assigned in the IEC program and its address then
written to this variable. The assignment in the declaration part can be performed by means
of a byte array, for example (BUF: ARRAY[1..10000] OF BYTE; for a 10,000 byte memory
area).
nSize: UDINT
The size of the memory area reserved for the buffer must appear here.
nReadPos: UDINT
This variable contains the address of the first list element relative to the first byte of the
reserved memory area.
nWritePos: UDINT
This variable contains the address of the first free byte following the list relative to the first
byte of the reserved memory area.
bFull: BOOL
If the list is full, with space only left for three further GEOINFO structures (safety buffer),
this variable will be set to TRUE by the APPENDOBJ function. DELETEOBJ will reset it to
FALSE if elements are deleted from the list.
bEndOfList: BOOL
The SoftMotion program organisation units that have an OutQueue structure as an input
always wait until the queue is completely full before processing it, in order to avoid a data
underrun (SMC_Interpolator), for example. As the OutQueue will no longer be full when it
comes to the last SMC_GEOINFO objects of a path, this variable must be set to TRUE once
the last SMC_GEOINFO object has been stored, in order to keep processing going. If the list
then becomes empty and needs to be filled again, EndOfList must be reset to FALSE.