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CheckPointer

 

This function checks pointers to ensure they are within the user programming area of memory. There should be no reason for the user to need to use this function.

 

Inputs:

 

ptToTest: POINTER TO BYTE; Destination address of the pointer.

 

iSize: DINT; Size of the type the pointer points to. (e.g: 20 for POINTER TO ARRAY [0..9] OF INT)

 

iGran: DINT; Granularity of the pointer access. This is the size of the biggest non-structured data type in the type the pointer points to. (e.g: 2 for POINTER TO ARRAY [0..9] OF INT)

 

bWrite: BOOL; Indicates read or write Access. TRUE = write access, FALSE = read access.

 

Return value: POINTER TO BYTE

 

 

Example in FBD:

Example in ST:

 

VarPOINTER_TO_BYTE1 := CheckPointer(VarPOINTER_TO_BYTE2, VarDINT1, VarDINT2, VarBOOL1);