CRC16_generic (FUN)¶

FUNCTION CRC16_generic : WORD

Function calculates the checksum CRC16 of the “MemoryBlock” in a generalized manner.

Typical input parameter:

• CRC16 standard :

  • wCRCInit := 16#0000

  • wPoly := 16#8005

  • xReflectInput := TRUE

  • xReflectOutput := TRUE

  • wXORout := 16#0000

• CRC16-CCITT :

  • wCRCInit := 16#FFFF

  • wPoly := 16#1021

  • xReflectInput := FALSE

  • xReflectOutput := FALSE

  • wXORout := 16#0000

• CRC16-Modbus :

  • wCRCInit := 16#FFFF

  • wPoly := 16#8005

  • xReflectInput := TRUE

  • xReflectOutput := TRUE

  • wXORout := 16#0000

Example:

sTest : STRING(10) := '123456789' ;
->
MEM.CRC16_generic(ADR(sTest),9,16#1021, FALSE, FALSE, 16#0000) = 16#29B1

InOut:

Scope	Name	Type	Comment
Return	CRC16_generic	WORD	function returns generalized CRC16 of “MemoryBlock”
Input	pMemoryBlock	POINTER TO BYTE	address of memory Block
	uiLength	UINT	length of MemoryBlock in byte
	wCRCInit	WORD	initial value for CRC value
	wPoly	WORD	polynom value for CRC algorithm
	xReflectInput	BOOL	reflect input data bytes
	xReflectOutput	BOOL	reflect CRC before final XOR
	wXORout	WORD	final XOR value before output