F17_SWAP

Higher/lower byte in 16-bit data exchange

The higher byte (higher 8-bits) and lower bytes (lower 8-bits) of a 16-bit area specified by d are exchanged if the trigger EN is in the ON-state. 1 byte means 8 bit.

Parameters

Output

d (WORD, INT, UINT): 16-bit area in which the higher and lower bytes are swapped (exchanged)

Remarks

Instead of using this F instruction, we recommend using the corresponding FP7 instruction: FP_SWAP_BYTES

(1) higher byte (8-bit)
(2) lower byte (8-bit)

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
		start: BOOL:=FALSE;
			(*activates the function*)
		swap_value: WORD:=16#2345;
			(*result after 0->1 leading
edge from start: 16#4523*)
	END_VAR

POU body

When the variable start is set to TRUE, the function is carried out.

LD body

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
        ACTIVE_NETWORK := 0 ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 7 ;
        NETWORK_BODY
B(B_CONTACT,,start,3,2,5,4,);
B(B_F,F17_SWAP!,Instance,5,1,12,5,,?DEN?AENO?Cd);
B(B_VAROUT,,swap_value,12,3,14,5,);
L(1,3,3,3);
L(1,0,1,7);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

IF start then
    F17_SWAP(swap_value);
END_IF;

IL body

LD	start	(* EN = start; Starting signal for the F17_SWAP function. *)
F17_SWAP	swap_value	(* d = swap_value (source/destination) *)
		(* Byte1Byte0 ﾞ Byte0Byte1 *)
ST	out	(* option *)