SMC_AvoidLoop (FB)¶

FUNCTION_BLOCK SMC_AvoidLoop

SMC_AvoidLoop removes loops from the path. It copies the input path, but cuts out the loops created by self-intersections. The resulting output path is free of self-intersections.

For a typical application see SMC_ToolRadiusCorr.

This function block needs to be activated/deactivated in the G-Code with G61/G60.

Note

The effectiveness and efficiency of SMC_AvoidLoop depend on the appropriate size of the input queue poqDataIn. A loop containing more objects than can be stored in poqDataIn is not detected. On the other hand, for each element, an intersection check is executed with all following elements of the queue. If the queue is large, completing these checks may take a long time.
SMC_AvoidLoop does not support ellipses (G08/G09). An error is reported if an ellipse element is detected while loop avoidance is active.
SMC_AvoidLoop only works in 2.5D mode (see G15). An error is reported if elements with full 3D mode (such as G10 elements) are detected while loop avoidance is active.

InOut:

Scope	Name	Type	Comment
Input	`bExecute`	`BOOL`	Execution starts on the rising edge.
	`bAbort`	`BOOL`	If `TRUE`, the current processing of this function block is aborted
	`bAppend`	`BOOL`	As long as this input remains `FALSE`, `poqDataOut` is cleared at each reset. As long as it remains `TRUE`, newly incoming data is written to the end of `poqDataOut`.
	`poqDataIn`	POINTER TO SMC_OUTQUEUE	This variable points to the SMC_OUTQUEUE structure which contains the SMC_GEOINFO objects of the path. Typically it points on the output `poqDataOut` of the preceding function block (e.g. the SMC_NCInterpreter ).
	`nSizeOutQueue`	`UDINT`	This variable contains the size of the data buffer in bytes. This buffer must be able to hold at least five SMC_GEOINFO objects. It is recommended to create the buffer as described by the example below. `ExampleBuf: Array[1..50] of SMC_GeoInfo` The appropriate buffer size can then be computed using `SIZEOF(ExampleBuf)`.
	`pbyBufferOutQueue`	POINTER TO ARRAY [0..0] OF SMC_GEOINFO	This input must point to the first byte of the memory area that is allocated for the SMC_OUTQUEUE structure. This area must be at least as big as defined in `nSizeOutQueue`. Typically the allocation of the memory buffer is done in the declaration part of the IEC-program by defining an array of SMC_GEOINFO e.g. `BUF: ARRAY[1..50] OF SMC_GEOINFO`; for a buffer that can store 50 path elements).
Output	`bDone`	`BOOL`	Set if the entire path has been processed
	`bBusy`	`BOOL`	`TRUE`, while execution of function block is not finished
	`bError`	`BOOL`	Signals, that an error has occurred within the function block
	`wErrorID`	`SMC_ERROR`	Error identification
	`poqDataOut`	POINTER TO SMC_OUTQUEUE	This variable points to a SMC_OUTQUEUE structure, which manages the SMC_GEOINFO objects of the output path.
	`iStatus`	SMC_AL_STATUS	This enum variable shows the current state of the function block.

Structure: