FP_HEX_TO_ASCII

HEX -> ASCII conversion

This FP instruction converts the hexadecimal data at s_Start into ASCII codes if the trigger EN is TRUE. n_Bytes specifies the number of bytes to be converted. The result is stored in the area specified by d_Start. ASCII code requires 8 bits (1 byte) to express one hexadecimal character. Upon conversion to ASCII, the data length will thus be twice the length of the source data.

Parameters

Input

s_Start (WORD, DWORD): Hexadecimal data
n_Bytes (INT, DINT, UINT, UDINT): Number of bytes

Output

d_Start (WORD, INT, UINT): Starting address of the data area for the results. The size is n_Bits * 2 words.

Remarks

The two characters that make up one byte are interchanged when stored. Two bytes are converted as one segment of data.

Error flags

sys_bIsOperationErrorHold (turns to TRUE and remains TRUE)

if the area specified using the index modifier exceeds the limit.
if the byte number specified by n_Bytes is greater than the area specified by s_Start
if the calculated result exceeds the area specified by d_Start
if n_Bytes= 0 or a negative value

sys_bIsOperationErrorNonHold (turns to TRUE for one scan)

if the area specified using the index modifier exceeds the limit.
if the byte number specified by n_Bytes is greater than the area specified by s_Start
if the calculated result exceeds the area specified by d_Start
if n_Bytes= 0 or a negative value

Example16-bit data

	Offset	Hex. characters			Offset	Converted ASCII codes	String equivalent
s_Start	0	16#ABCD	Þ	d_Start	0	16#4443	DC
n_Bytes		16#0002				16#4241	BA

Example32-bit data

	Offset	Hex. characters			Offset	Converted ASCII codes	String equivalent
s_Start	0	16#1234	Þ	d_Start	0	16#3433	43
	1	16#5678			1	16#3231	21
n_Bytes		16#0004				16#3837	87
						16#3635	65

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
		bStart: BOOL:=FALSE;
		awInput: ARRAY [0..2] OF WORD:=[16#ABCD,2(0)];
		awResult: ARRAY [0..5] OF WORD:=[6(16#FFFF)];
	END_VAR

POU body

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

LD body

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 9 ;
        NETWORK_BODY
B(B_COMMENT,,After conversion: ø^awResult[0]=16#4443ø^awResult[1]=16#4241ø^awResult[2]=16#3030ø^awResult[3]=16#3030ø^awResult[4] is not written,23,0,38,6,);
B(B_CONTACT,,bStart,4,5,6,7,R);
B(B_F,FP_HEX_TO_ASCII!,,12,4,22,9,,?DEN?D@'s'?Dn_Chars?AENO?Cd_Start);
B(B_VARIN,,awInput[0],10,6,12,8,);
B(B_VAROUT,,awResult[0],22,6,24,8,);
B(B_VARIN,,4,10,7,12,9,);
L(1,0,1,9);
L(1,6,4,6);
L(6,6,12,6);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

if (DF(bStart)) then
	FP_HEX_TO_ASCII(s_Start := awInput[0], n_Bytes := 4, d_Start => awResult[0]);
	(* After conversion: 
		awResult[0]=16#4443
		awResult[1]=16#4241
		awResult[2]=16#3030
		awResult[3]=16#3030
		awResult[4] is not written *)
end_if;