SMC_LimitDynamics (FB)¶

FUNCTION_BLOCK SMC_LimitDynamics

The function block reduces the velocity and acceleration/deceleration of the path so that the resulting velocities, accelerations and decelerations of the cartesian and additional axes do not exceed the input values dMaxVel, dMaxAcc and dMaxDec.

Note

SMC_LimitDynamics was renamed and was previously named SMC_LimitAddAxisDynamics.

Using SMC_LimitDynamics

Assignment of input poqDataIn

Typically, poqDataOut of the previous function block is fed to the input poqDataIn. That can be an instance of the function block SMC_NCDecoder or SMC_SmoothPath.

Allocating memory for the preprocessing of the path elements

If the function block is executed, memory is needed, in which the processing elements are copied. The memory area must be able to hold at least five SMC_GEOINFO objects. If the memory is too small, the function block performs no actions. The memory is declared in the IEC program as an array of objects of type SMC_GEOINFO.

PROGRAM Path
VAR
    buf2: ARRAY[1..50] OF SMC_GeoInfo;
END_VAR

Feeding the allocated memory area

The size of the memory is determined by the operator SIZEOF in the implementation of the IEC program and is fed to the input nSizeOutQueue. The address of the memory is defined with the operator ADR and is fed to the input pbyBufferOutQueue.

InOut:

Scope	Name	Type	Comment
Input	`bExecute`	`BOOL`	Execution starts on the rising edge.
	`bAbort`	`BOOL`	`TRUE`: Aborts the processing of the function block
	`bAppend`	`BOOL`	`FALSE`: Starts emptying `poqDataOut` on a rising edge at `bExecute`
	`poqDataIn`	POINTER TO SMC_OUTQUEUE	Pointer to data of structure SMC_OUTQUEUE containing the path objects of typ SMC_GEOINFO.
	`wAxis`	`WORD`	Bit field of the axes on that the operation is executed: X: Bit 0 Y: Bit 1 Z: Bit 2 A: Bit 3 B: Bit 4 C: Bit 5 P: Bit 6 Q: Bit 7 U: Bit 8 V: Bit 9 W: Bit 10 Example: 16#0104 causes limitation of Z and U
	`dMaxVel`	`LREAL`	Maximum speed value for the defined axes
	`dMaxAccDec`	`LREAL`	Maximum acceleration or deceleration value for the defined axes
	`bIncludePathSettings`	`BOOL`	`TRUE`: Limits the velocity, acceleration or deceleration (F, E +, E-) on the values defined in `dMaxVel` and `dMaxAccDec`
	`nSizeOutQueue`	`UDINT`	Size in bytes of the data buffer `pbyBufferOutQueue`, in which the path elements are copied. If the value is set, it may not be changed except after a reset.
	`pbyBufferOutQueue`	POINTER TO ARRAY [0..0] OF SMC_GEOINFO	Pointer to the first byte of the storage area created for the path elements. If the value is set, it may not be changed except after a reset.
	`bStrictlyHoldAccDecABC`	`BOOL`	If `TRUE`, the maximal accelerations and decelerations of A, B, C are strictly held. Otherwise, we use a heuristic that may lead to quicker profiles, but occasionally violate the A/B/C-acceleration-limit, if A/B/C move quickly while there is an ac- / deceleration on the path.
Output	`bDone`	`BOOL`	`TRUE`: input date from `poqDataIn` have been precessed fully. After that, the function block performs no action until a reset is detected. When `bExecute` is set to `FALSE`, `bDone` is reset to `FALSE`.
	`bBusy`	`BOOL`	`TRUE`: Function block in execution
	`bError`	`BOOL`	`TRUE`: Error has occurred
	`wErrorID`	`SMC_ERROR`	Error identification
	`poqDataOut`	POINTER TO SMC_OUTQUEUE	Pointer to data of structure SMC_OUTQUEUE containing the path elements of typ SMC_GEOINFO.

Structure: