Conversion: STRING, WSTRING

The operators convert a string (STRING or WSTRING) into the specified target data type and return a type-converted value.

A conversion with a meaningful result is only possible when the operand matches the target data type according to the IEC 61131-3 standard. This is the case if the value of the operand corresponds to a valid constant (literal) of the target data type.

Convertible strings contain:

Number with type prefix (example: '16#FFFFFFFF')
Number with grouping characters (example: '2#1111_1111')
Note: The international weight and measure grouping character (thin space) is not accepted. Only the underscore is accepted.
Floating-point number, also in exponential notation (example: '9.876' or '1.2E-34')
Note: Floating-point numbers are not convertible. The comma is treated and truncated as a following character.
Time, time of day, and date specification with prefix and size (example: 'T#2h', 'DT#2019-9-9-12:30:30.9')
Infinite values (example: '1.7E+400')
Additional character after a number (example: '2m' or '3.14')
These are truncated. Additional characters before a number are not permitted.
Spaces before (example: '3.14')

Call syntax: STRING_TO_<target type>(<operand>) , WSTRING_TO_<target type>(<operand>)

Operand	Data Type	Description
Variable or literal	`STRING`, `WSTRING`	STRING, WSTRING

Table 14. Casting operators: STRING/WSTRING_TO_<target type>

Operator: STRING	Operator: WSTRING	Example	Return Value	Description
`STRING_TO___UXINT`	`WSTRING_TO___UXINT`			__UXINT, __XINT, __XWORD
`STRING_TO___XINT`	`WSTRING_TO___XINT`			__UXINT, __XINT, __XWORD
`STRING_TO___XWORD`	`WSTRING_TO___XWORD`			__UXINT, __XINT, __XWORD
`STRING_TO_BIT`	`WSTRING_TO_BIT`			BIT
`STRING_TO_BOOL`	`WSTRING_TO_BOOL`	`STRING_TO_BOOL('TRUE')` `STRING_TO_BOOL('true')` `WSTRING_TO_BOOL("TRUE")` `WSTRING_TO_BOOL("true")`	`TRUE`	BOOL
`STRING_TO_BYTE`	`WSTRING_TO_BYTE`			Integer
`STRING_TO_DATE`	`WSTRING_TO_DATE`	`STRING_TO_DATE('DATE#2019-9-9')` `WSTRING_TO_DATE("DATE#2019-9-9")`	`D#2019-9-9`	Syntax: `D#yyyy-MM-dd` Data type: DATE
`STRING_TO_DINT`	`WSTRING_TO_DINT`			If the output data type is larger, then information may be lost. Integer
`STRING_TO_DT`	`WSTRING_TO_DT`	`STRING_TO_DT('DT#2019-9-9-1:1:1.1')` `WSTRING_TO_DT("DT#2019-9-9-1:1:1.1")`	`DT#2019-9-9-1:1:1` `DT#2019-9-9-1:1:1`	Syntax: `DT#yyyy-MM-dd-hh:mm:ss` Data type: DATE
`STRING_TO_DWORD`	`WSTRING_TO_DWORD`			Integer
`STRING_TO_INT`	`WSTRING_TO_INT`	`STRING_TO_INT('123abc')` `WSTRING_TO_INT("123abc")`	`123`	Integer
`STRING_TO_LDATE`	`WSTRING_TO_LDATE`			Syntax: `LDATE#yyyy-MM-dd` Only the day is displayed. Data type: DATE
`STRING_TO_LDT`	`WSTRING_TO_LDT`			Syntax: `LDT#yyyy-MM-dd-hh:mm:ss.sss` Data type: DATE
`STRING_TO_LINT`	`WSTRING_TO_LINT`			Integer
`STRING_TO_LREAL`	`WSTRING_TO_LREAL`	`STRING_TO_LREAL('1.7E+308')` `WSTRING_TO_LREAL("1.7E+308")`	`1.7000000000000001E+308`	REAL, LREAL
`STRING_TO_LTIME`	`WSTRING_TO_LTIME`	`STRING_TO_LTIME('LTIME#709ms551us615ns')` `STRING_TO_LTIME('LTIME#1ms')` `WSTRING_TO_LTIME("LTIME#1ms")`	`LTIME#709ms551us615ns` `LTIME#1ms`	Data type: TIME, LTIME
`STRING_TO_LTOD`	`WSTRING_TO_LTOD`			Syntax: `LTOD#hh:mm:ss.sssssssss` Data type: DATE
`STRING_TO_LWORD`	`WSTRING_TO_LWORD`	`STRING_TO_LWORD('16#0123456789ABCDEF')` `WSTRING_TO_LWORD("16#0123456789ABCDEF")`	`81985529216486895`	Integer
`STRING_TO_REAL`	`WSTRING_TO_REAL`	`STRING_TO_REAL('1.234')` `WSTRING_TO_REAL("1.234")`	`1.234`	When converting from a larger value range, information may be lost or an undefined result may be returned. REAL, LREAL
`STRING_TO_SINT`	`WSTRING_TO_SINT`			Integer
-	`WSTRING_TO_STRING`	`WSTRING_TO_STRING("Hello World!")`	`Hello World!`
`STRING_TO_TIME`	`WSTRING_TO_TIME`	`STRING_TO_TIME('T#5d4h3m2s')` `WSTRING_TO_TIME("T#5d4h3m2s")`	`T#5d4h3m2s`	Data type: TIME, LTIME
`STRING_TO_TOD`	`WSTRING_TO_TOD`	`STRING_TO_TOD('TOD#20:15')` `WSTRING_TO_TOD("TOD#20:15")`	`TOD#20:15:0`	Data type: DATE
`STRING_TO_UDINT`	`WSTRING_TO_UDINT`			Integer
`STRING_TO_UINT`	`WSTRING_TO_UINT`			Integer
`STRING_TO_ULINT`	`WSTRING_TO_ULINT`	`STRING_TO_ULINT('615')` `WSTRING_TO_ULINT("615")`	`615`	Integer
`STRING_TO_USINT`	`WSTRING_TO_USINT`			Integer
`STRING_TO_WORD`	`WSTRING_TO_WORD`			Integer
`STRING_TO_WSTRING`	-	`STRING_TO_WSTRING('Hello World!')`	`"Hello World!"`	WSTRING

Converting to a Boolean value

Operator STRING_TO_BOOL: A value of TRUE is returned only if the operand value is 'TRUE' or 'true'. On the other hand, FALSE is returned for 'True'.

Operator WSTRING_TO_BOOL: A value of TRUE is returned only if the operand value is "TRUE" or "true". On the other hand, FALSE is returned for "True".

Examples

Example 171. FB_ConvertStrings

Declaration

FUNCTION_BLOCK FB_ConvertStrings
VAR_INPUT
END_VAR
VAR_OUTPUT
END_VAR
VAR
	 xReturn_0: BOOL;
	xReturn_1: BOOL;
	dateReturn: DATE;
	dtReturn: DATE_AND_TIME;
	iReturn: INT;
	lrReturn: LREAL;
	lrReturn_0: LREAL;
	lwReturn: LWORD;
	lwReturn_0: LWORD;
	lwReturn_1: LWORD;
	ltReturn: LTIME;
	ltReturn_0: LTIME;
	ltReturn_1: LTIME;
	ltReturn_2: LTIME;
	rReturn: REAL;
	rReturn_0: REAL;
	timReturn: TIME;
	timReturn0: TIME;
	timReturn1: TIME;
	timReturn2: TIME;
	todReturn: TIME_OF_DAY;
	todReturn0: TIME_OF_DAY;
	todReturn1: TIME_OF_DAY;
	todReturn2: TIME_OF_DAY;
	uliReturn: ULINT;
	uliReturn_0: ULINT;
	uliReturn_1: ULINT;
	wReturn: WORD;
	wReturn_0: WORD;
	wReturn_1: WORD;
	wstrReturn: WSTRING;
	wstrReturn_0: WSTRING;
	dtReturn2: DATE_AND_TIME;
END_VAR

Implementation

FUNCTION_BLOCK FB_ConvertStrings
VAR_INPUT
END_VAR
VAR_OUTPUT
END_VAR
VAR
        xReturn_0: BOOL;
        xReturn_1: BOOL;
        dateReturn: DATE;
        dtReturn: DATE_AND_TIME;
        iReturn: INT;
        lrReturn: LREAL;
        lrReturn_0: LREAL;
        lwReturn: LWORD;
        lwReturn_0: LWORD;
        lwReturn_1: LWORD;
        ltReturn: LTIME;
        ltReturn_0: LTIME;
        ltReturn_1: LTIME;
        ltReturn_2: LTIME;
        rReturn: REAL;
        rReturn_0: REAL;
        timReturn: TIME;
        timReturn0: TIME;
        timReturn1: TIME;
        timReturn2: TIME;
        todReturn: TIME_OF_DAY;
        todReturn0: TIME_OF_DAY;
        todReturn1: TIME_OF_DAY;
        todReturn2: TIME_OF_DAY;
        uliReturn: ULINT;
        uliReturn_0: ULINT;
        uliReturn_1: ULINT;
        wReturn: WORD;
        wReturn_0: WORD;
        wReturn_1: WORD;
        wstrReturn: WSTRING;
        wstrReturn_0: WSTRING;
END_VAR
xReturn_0 := STRING_TO_BOOL('FALSE');
xReturn_1 := STRING_TO_BOOL('TRUE');
dateReturn := STRING_TO_DATE('DATE#2019-9-9');
dtReturn := STRING_TO_DT('DT#2019-9-9-1:1:1.1');
iReturn := STRING_TO_INT('123abc');
lrReturn := STRING_TO_LREAL('4.94E-323');
lrReturn_0 := STRING_TO_LREAL('1.7E+308');
lwReturn := STRING_TO_LWORD('16#FFFF_FFFF_FFFF_FFFF');
lwReturn_0 := STRING_TO_LWORD('16#0123456789ABCDEF');
lwReturn_1 := STRING_TO_LWORD('16#0123456789ABCDEF');
ltReturn := STRING_TO_LTIME('LTIME#213503d23h34m33s709ms551us615ns');
ltReturn_0 := STRING_TO_LTIME('LTIME#0ns');
ltReturn_1 := STRING_TO_LTIME('LTIME#1ms');
ltReturn_2 := STRING_TO_LTIME('LTIME#2s');
rReturn := STRING_TO_REAL('6.543e21');
rReturn_0 := STRING_TO_REAL('1.234');
timReturn := STRING_TO_TIME('T#5d4h3m2s');
timReturn0 := STRING_TO_TIME('TIME#1s');
timReturn1 := STRING_TO_TIME('1s');
timReturn2 := STRING_TO_TIME('TIME#5s');
todReturn := STRING_TO_TOD('TOD#12:0:0.1');
todReturn0 := STRING_TO_TOD('TOD#0:0:0.0');
todReturn1 := STRING_TO_TOD('20:15');
todReturn2 := STRING_TO_TOD('TOD#20:15');
uliReturn := STRING_TO_ULINT('18446744073709551615');
uliReturn_0 := STRING_TO_ULINT('1');
uliReturn_1 := STRING_TO_ULINT('0');
wReturn := STRING_TO_WORD('16#FFFF_0000');
wReturn_0 := STRING_TO_WORD('34abc');
wReturn_1 := STRING_TO_WORD('16#34abc');
wstrReturn := STRING_TO_WSTRING('Hello World!');
wstrReturn_0 := STRING_TO_WSTRING('123456789');

Example 172. FB_ConvertWstrings in ST

Declaration

FUNCTION_BLOCK FB_ConvertWstrings
VAR_INPUT
END_VAR
VAR_OUTPUT
END_VAR
VAR
	xReturn_0: BOOL;
	xReturn_1: BOOL;
	dateReturn: DATE;
	dtReturn: DATE_AND_TIME;
	iReturn: INT;
	lrReturn: LREAL;
	lrReturn_0: LREAL;
	lwReturn: LWORD;
	lwReturn_0: LWORD;
	lwReturn_1: LWORD;
	ltReturn: LTIME;
	ltReturn_0: LTIME;
	ltReturn_1: LTIME;
	ltReturn_2: LTIME;
	rReturn: REAL;
	rReturn_0: REAL;
	timReturn: TIME;
	timReturn0: TIME;
	timReturn1: TIME;
	timReturn2: TIME;
	todReturn: TIME_OF_DAY;
	todReturn0: TIME_OF_DAY;
	todReturn1: TIME_OF_DAY;
	todReturn2: TIME_OF_DAY;
	uliReturn: ULINT;
	uliReturn_0: ULINT;
	uliReturn_1: ULINT;
	wReturn: WORD;
	wReturn_0: WORD;
	wReturn_1: WORD;
	wstrReturn: WSTRING;
	wstrReturn_0: WSTRING;
END_VAR

Implementation in ST

FUNCTION_BLOCK FB_ConvertWstrings
VAR
        xReturn_0: BOOL;
        xReturn_1: BOOL;
        dateReturn: DATE;
        dtReturn: DATE_AND_TIME;
        iReturn: INT;
        lrReturn: LREAL;
        lrReturn_0: LREAL;
        lwReturn: LWORD;
        lwReturn_0: LWORD;
        lwReturn_1: LWORD;
        ltReturn: LTIME;
        ltReturn_0: LTIME;
        ltReturn_1: LTIME;
        ltReturn_2: LTIME;
        rReturn: REAL;
        rReturn_0: REAL;
        timReturn: TIME;
        timReturn0: TIME;
        timReturn1: TIME;
        timReturn2: TIME;
        todReturn: TIME_OF_DAY;
        todReturn0: TIME_OF_DAY;
        todReturn1: TIME_OF_DAY;
        todReturn2: TIME_OF_DAY;
        uliReturn: ULINT;
        uliReturn_0: ULINT;
        uliReturn_1: ULINT;
        wReturn: WORD;
        wReturn_0: WORD;
        wReturn_1: WORD;
        wstrReturn: WSTRING;
        wstrReturn_0: WSTRING;
END_VAR

xReturn_0 := WSTRING_TO_BOOL("FALSE");
xReturn_1 := WSTRING_TO_BOOL("TRUE");
dateReturn := WSTRING_TO_DATE("DATE#2019-9-9");
dtReturn := WSTRING_TO_DT("DT#2019-9-9-1:1:1.1");
iReturn := WSTRING_TO_INT("123abc");
lrReturn := WSTRING_TO_LREAL("4.94E-323");
lrReturn_0 := WSTRING_TO_LREAL("1.7E+308");
lwReturn := WSTRING_TO_LWORD("16#FFFF_FFFF_FFFF_FFFF");
lwReturn_0 := WSTRING_TO_LWORD("16#0123456789ABCDEF");
lwReturn_1 := WSTRING_TO_LWORD("16#0123456789ABCDEF");
ltReturn := WSTRING_TO_LTIME("LTIME#213503d23h34m33s709ms551us615ns");
ltReturn_0 := WSTRING_TO_LTIME("LTIME#0ns");
ltReturn_1 := WSTRING_TO_LTIME("LTIME#1ms");
ltReturn_2 := WSTRING_TO_LTIME("LTIME#2s");
rReturn := WSTRING_TO_REAL("6.543e21");
rReturn_0 := WSTRING_TO_REAL("1.234");
timReturn := WSTRING_TO_TIME("T#5d4h3m2s");
timReturn0 := WSTRING_TO_TIME("TIME#1s");
timReturn1 := WSTRING_TO_TIME("1s");
timReturn2 := WSTRING_TO_TIME("TIME#5s");
todReturn := WSTRING_TO_TOD("TOD#12:0:0.1");
todReturn0 := WSTRING_TO_TOD("TOD#0:0:0.0");
todReturn1 := WSTRING_TO_TOD("20:15");
todReturn2 := WSTRING_TO_TOD("TOD#20:15");
uliReturn := WSTRING_TO_ULINT("18446744073709551615");
uliReturn_0 := WSTRING_TO_ULINT("1");
uliReturn_1 := WSTRING_TO_ULINT("0");
wReturn := WSTRING_TO_WORD("16#FFFF_0000");
wReturn_0 := WSTRING_TO_WORD("34abc");
wReturn_1 := WSTRING_TO_WORD("16#34abc");

Example 173. FBD implementation language