FP_SWAP_BYTES_BLOCK

Exchange higher bytes and lower bytes

This FP instruction exchanges the higher bytes with the lower bytes of all words within the data area specified by s_Start and n_Words if the trigger EN is TRUE. The result is transferred to d_Start.

Parameters

Input

s_Start (WORD): Starting address of the source data area
n_Words (WORD, INT, UINT): Number of words (1–65535, in case of 0 no operation is executed)

Output

d_Start (WORD): Starting address of the destination data area

Error flags

sys_bIsOperationErrorHold (turns to TRUE and remains TRUE)

if the area specified using the index modifier exceeds the limit.

sys_bIsOperationErrorNonHold (turns to TRUE for one scan)

if the area specified using the index modifier exceeds the limit.

Example

POU header

All input and output variables used for programming this function have been declared in the POU header. The same POU header is used for all programming languages.

	VAR
		arrWordValues: ARRAY [0..7] OF WORD:=[8(16#88AA)];
		arraWordValuesSwapped: ARRAY [0..7] OF WORD:=[8(0)];
		bEnable: BOOL:=FALSE;
		iNumberOfWords: INT:=8;
	END_VAR

POU body

When the variable bEnable is set to TRUE, the function is executed.

LD body

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
        ACTIVE_NETWORK := 0 ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 5 ;
        NETWORK_BODY
B(B_F,FP_SWAP_BYTES_BLOCK!,,15,0,28,5,,?DEN?Ds_Start?Dn_Words?AENO?Cd_Start);
B(B_VARIN,,arrWordValues[0],13,2,15,4,);
B(B_VARIN,,iNumberOfWords,13,3,15,5,);
B(B_VAROUT,,arraWordValuesSwapped[0],28,2,30,4,);
B(B_CONTACT,,bEnable,4,1,6,3,);
L(1,2,4,2);
L(6,2,15,2);
L(1,0,1,5);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

if (bEnable) then
    FP_SWAP_BYTES_BLOCK(s_Start := arrWordValues[0],
                        n_Words := iNumberOfWords,
                        d_Start => arraWordValuesSwapped[0]);
END_IF;