FB_MemBufferMerge

VAR_INPUT

VAR_INPUT
    eCmd      : E_EnumCmdType := eEnumCmd_First;
    pBuffer   : POINTER TO BYTE;
    cbBuffer  : UDINT;
    pSegment  : POINTER TO BYTE := 0;
    cbSegment : UDINT := 0;
END_VAR

eCmd: Control parameter for the enumeration block (type: E_EnumCmdType). eEnumCmd_First adds the first segment, eEnumCmd_Next adds the next segment. No other parameters are used.

pBuffer: Address (pointer) for the target buffer variable. The address can be determined with the ADR operator.

cbBuffer: Maximum available size (in bytes) of the target buffer variables. The size can be determined with the SIZEOF operator.

pSegment: Address (pointer) for the next data segment to be added (optional, may be zero). The address can also be determined with the ADR operator.

cbSegment: Size of the next data segment to be added (optional, may be zero). The size can also be determined with the SIZEOF operator.

VAR_OUTPUT

VAR_OUTPUT
    bOk    : BOOL;
    cbSize : UDINT;
END_VAR

bOk: TRUE = success, FALSE = buffer overflow or faulty input parameters.

cbSize: Current buffer fill status (number of data bytes in the buffer).

Example:

In the following example, the large data segment is converted to a hexadecimal string after the smaller data segments have been consolidated (for test purposes).

PROGRAM MAIN
VAR
    bMerge    : BOOL := TRUE;
    fbMerge   : FB_MemBufferMerge;
    buffer    : ARRAY[0..25] OF BYTE;
    seg1      : ARRAY[0..5] OF BYTE := [0,1,2,3,4,5];
    seg2      : ARRAY[0..3] OF BYTE := [6,7,8,9];
    seg3      : ARRAY[0..9] OF BYTE := [10,11,12,13,14,15,16,17,18,19];
    sHex      : T_MaxString;
END_VAR

IF bMerge THEN
    bMerge := FALSE;

    fbMerge( eCmd := eEnumCmd_First, pBuffer := ADR(buffer), cbBuffer := SIZEOF(buffer), pSegment := ADR(seg1), cbSegment:= SIZEOF(seg1) );
    fbMerge( eCmd := eEnumCmd_Next, pBuffer := ADR(buffer), cbBuffer := SIZEOF(buffer), pSegment := ADR(seg2), cbSegment:= SIZEOF(seg2 ) );
    fbMerge( pBuffer := ADR(buffer), cbBuffer := SIZEOF(buffer), pSegment := ADR(seg3), cbSegment:= SIZEOF(seg3) );
    fbMerge( pBuffer := ADR(buffer), cbBuffer := SIZEOF(buffer), pSegment := 0, cbSegment:= 0 );(* merge zero length segment *)
    fbMerge( pBuffer := ADR(buffer), cbBuffer := SIZEOF(buffer), pSegment := ADR(seg3), cbSegment:= SIZEOF(seg3) );
    IF NOT fbMerge.bOk THEN
        ;(* TODO: Error handler *)
    END_IF

    sHex := DATA_TO_HEXSTR( pData := ADR(buffer), cbData := fbMerge.cbSize, FALSE );
END_IF

Requirements