FP_BCD_TO_ASCII

BCD -> ASCII conversion

This FP instruction converts the BCD code at s1 to ASCII code if the trigger EN is TRUE. s2_Control specifies the number of bytes to be converted and the conversion direction.

The result is stored in the area specified by d_Start. ASCII code requires 8 bits (1 byte) to express 1 BCD character. Upon conversion to ASCII, the data length will thus be twice the length of the source data.

Parameters

Input

s1 (WORD, DWORD): BCD code
s2_Control (WORD): Number of bytes and conversion direction

Output

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

Remarks

Specifying the control code s2_Control

(1) data size to be converted:
16-bit: 1–2 bytes to be converted

32-bit: 1–4 bytes to be converted
(2) always 0
(3) conversion direction:
0: forward

1: reverse

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

Forward direction:
Reverse direction:

ASCII HEX codes to express BCD characters:

BCD character	ASCII HEX code
0123456789	16#3016#31 16#32 16#33 16#34 16#35 16#36 16#37 16#38 16#39

Error flags

sys_bIsOperationErrorHold (turns to TRUE and remains TRUE)

if the area specified using the index modifier exceeds the limit.
if the data specified by s1_Start is not BCD data
if the number of bytes specified by s2_Control is greater than the area specified by s1_Start
if the conversion result is greater than the data area specified by d_Start
if s2_Control = 0
if the conversion direction is out of range
if the number of bytes specified in s2_Control is greater than 4

sys_bIsOperationErrorNonHold (turns to TRUE for one scan)

if the area specified using the index modifier exceeds the limit.
if the data specified by s1_Start is not BCD data
if the number of bytes specified by s2_Control is greater than the area specified by s1_Start
if the conversion result is greater than the data area specified by d_Start
if s2_Control = 0
if the conversion direction is out of range
if the number of bytes specified in s2_Control is greater than 4

Example 16-bit data, forward direction, 2 bytes (characters)

	Offset	BCD characters			Offset	Converted ASCII codes	BCD equivalent
s1	0	16#1234	Þ	d_Start	0	16#3433	43
s2_Control		16#0002				16#3231	21

Example 16-bit data, reverse direction, 2 bytes (characters)

	Offset	BCD characters			Offset	Converted ASCII codes	BCD equivalent
s1	0	16#1234	Þ	d_Start	0	16#3231	21
s2_Control		16#1002				16#3433	43

Example 32-bit data, forward direction, 4 bytes (characters)

	Offset	BCD characters			Offset	Converted ASCII codes	BCD equivalent
s1	0	16#5678	Þ	d_Start	0	16#3837	87
	1	16#1234			1	16#3635	65
s2_Control		16#0004				16#3433	43
						16#3231	21

Example 32-bit data, reverse direction, 4 bytes (characters)

	Offset	BCD characters			Offset	Converted ASCII codes	BCD equivalent
s1	0	16#5678	Þ	d_Start	0	16#3231	21
	1	16#1234			1	16#3433	43
s2_Control		16#1004				16#3635	65
						16#3837	87

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;
		wInput: WORD:=16#1234;
		awResult: ARRAY [0..2] OF WORD:=[3(0)];
	END_VAR

POU body

When the variable bStart is set to TRUE, the function is carried out. Two bytes from s1_Start are converted to an ASCII value in reverse direction.

LD body

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 8 ;
        NETWORK_BODY
B(B_COMMENT,,After conversion: ø^awResult[0]=16#3231ø^awResult[1]=16#3433ø^awResult[2] is not written,24,1,39,5,);
B(B_CONTACT,,bStart,4,4,6,6,R);
B(B_F,FP_BCD_TO_ASCII!,,12,3,22,8,,?DEN?D@'s1'?Ds2_Control?AENO?Cd_Start);
B(B_VARIN,,wInput,10,5,12,7,);
B(B_VAROUT,,awResult[0],22,5,24,7,);
B(B_VARIN,,16#1002,10,6,12,8,);
L(1,0,1,8);
L(1,5,4,5);
L(6,5,12,5);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

If (DF(bStart)) Then
    FP_BCD_TO_ASCII(s1 := wInput, s2_Control := 16#1002,
                    d_Start => awResult[0]);
            (* After conversion: 
			awResult[0]=16#3231
			awResult[1]=16#3433
			awResult[2] is not written *)

End_if;