Buffer comp

BUFFER_COMP

Type Function	INT
Input PT1	POINTER (address of the first Buffer )
Size1	INT (size of the first buffer)
PT2	POINTER (address of the second Buffer )
SIZE2	INT (size of the second buffer)
START	INT (search begin from start)
Output	INT (position found)
	The function BUFFER_COMP checks whether the content of the array PT2 occurs in the array PT1 from position START. If PT2 is found in PT1, so the function returns the position in PT1, starting from 0. If PT2 is not found in PT1, -1 is returned. BUFFER_COMP can also be used for comparison of two equally sized arrays.
When called, a Pointer to the array and its size in bytes is passed to the function. In CoDeSys the call reads	BUFFER_COMP(ADR(BUF1), SIZEOF(BUF1), ADR(BUF2), SIZEOF(BUF2)), where BUF1 and BUF2 are the names of the arrays to be manipulated. ADR() is a standard function which indentifies the Pointer to the array and SIZEOF() is a standard function, which determines the size of the array. The function only returns TRUE. The array specified by the Pointer is manipulated directly in memory. This type of processing arrays is very efficient because no additional memory is required and no surrender values must be copied.

Example:

BUFFER_COMP(ADR(BUF1), SIZEOF(BUF1), ADR(BUF2), SIZEOF(BUF2))