SMC_NCDecoder (FB)¶

FUNCTION_BLOCK FINAL SMC_NCDecoder

This function block is used to convert a CNC program (Din 66025, G-code), into a list of SMC_GEOINFO objects. In each cycle, one line of the program is decoded.

InOut:

Scope	Name	Type	Initial	Comment
Inout	ncprog	SMC_CNC_REF		This variable holds the CNC program. The program may have been created by the IEC-program or within the CNC-Editor.
Input	bExecute	BOOL		Execution starts on the rising edge.
	bAbort	BOOL		If TRUE, the current processing of this function block is aborted
	bAppend	BOOL		The input bAppend is intended for the use-case of appending a further G-Code file to the last one, keeping the decoder state. The result is the same as if both G-Code files would have been copied into a single file, with a few exceptions as mentioned below. The out-queue is not cleared, only the bEndOfData flag is reset. State like the decoder coordinate system (G54, G55, G56), the arc coordinate system (G15, G16, G17, G18, G19), the current mode (G90, G91, G98, G99), or the implicit variable is kept and used for the new G-Code. Restrictions: The first rising edge of bExecute must have bAppend = FALSE, otherwise the error SMC_CNC_APPEND_ON_FIRST_RISING_EDGE is returend. Splines (G05/G10) cannot be continued. If the first G-Code ends with a spline, and the following G-Code starts with a spline, a spline stop is done at the end of the previous G-Code, nevertheless. The inputs piStartPosition and vStartToolLength are ignored if bAppend is TRUE.
	bStepSuppress	BOOL		When this input is TRUE, lines of the CNC program starting with ‚/’ will be ignored. Otherwise they will be processed.
	piStartPosition	SMC_POSINFO		Start position of the path. Only the position of the axes (piStartPosition.dX/dY/dZ/dA/dB/dC/dA1/…/dA6) is used, the other members of piStartPosition are ignored.
	vStartToolLength	SMC_Vector3d		Start tool length.
	nSizeOutQueue	UDINT		This variable contains the size of the data buffer, the list of SMC_GEOINFO structure objects will be written to. This buffer must be able to hold at least five SMC_GEOINFO objects. Otherwise, the function block will not execute any actions at all. Its size may be predefined, but may be modified later only during a reset. It is recommended to create the buffer as described by the example below: ExampleBuf: Array[1..50] of SMC_GeoInfo; The appropriate buffer size will then be retrieved by use of the operator 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). The value may be predefined, but may be modified later on only during a reset.
	bEnableSyntaxChecks	BOOL		Turns on syntax checks that will detect invalid G-code and stop with an error in this case. It is recommended to use the syntax checks.
	eOriConv	SMC_ORI_CONVENTION	SMC_ORI_CONVENTION.ADDAXES	Defines the way the orientation in the A/B/C words is interpreted. For movement commands (such as G01, G02, …), the value determines how A/B/C are treated. For values other than SMC_ORI_CONVENTION.``ADDAXES``, the angles A/B/C may be normalized, even if no coordinate rotation has been programmed. For example with orientation convention ZYZ, a programmed orientation of A=90° B=0° C=0° may result in the (equivalent) rotation A=0° B=0° C=90° in the path element. For commands that set the decoder coordinate system (G54/G55/G56), the value determines how the coordinates A/B/C are treated. If the value is SMC_ORI_CONVENTION.``ADDAXES``, then A/B/C are treated as independent additional axes, for which offsets are set. For all other values, A/B/C are treated as an orientation, and the decoder coordinate system is rotated accordingly. Note If used with tool correction functions such as SMC_ToolLengthCorr, the same orientation convention has to be used there.
	dCircleTolerance	LREAL		Tolerance to decide whether the definition of a circle makes sense. case definition via target-position and radius: If the distance between start- and end-position (both projected onto the circle plane) is greater than 2 * the radius + MAX(fCircleTolerance, 1e-06), the circle will be converted into a line. case definition via target- and center-position: Let x be the maximum of the distance between start- and center-position and the distance between target- and center-position (projecting everything onto the circle plane). If those distances differ by more than MAX(fCircleTolerance, 0.1 * x), the circle will be converted into a line.
	dPrecision	LREAL		The precision of the path in technical units. This value indicates the precision of the positions read from the G-Code. For example, if the G-Code is given with 3 places after the decimal point, the precision should be set to 1e-3 units. The precision must be non-negative. The precision value is used for example by path preprocessors like SMC_ToolRadiusCorr and SMC_AvoidLoop.
Output	bDone	BOOL		This variable will be set to TRUE as soon as the input data has been processed completely. The function block will not perform any further actions until it gets reset.
	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		Pointer to the SMC_OUTQUEUE structure that manages the decoded SMC_GEOINFO objects.
	iStatus	SMC_DEC_STATUS		The current status.
	iLineNumberDecoded	DINT		The variable contains the 0-based line number of the CNC file.
	GCodeText	SMC_GCODE_TEXT		The G-Code text.

Methods:

GetDCS

Structure: