You can explicitly call type conversion operators. The type conversion operators described
below are available for typed conversions from one elementary type to another elementary
type, as well as for overloading. Conversions from a "larger" type to a "smaller"
type are also implicitly possible (for example, from INT to BYTE or from DINT to WORD).
Typed conversion: <elementary data type> _TO_ another elementary data type>
Overloaded conversion: TO_ <elementary data type>
Elementary Data Types
<elementary data type> = __UXINT | __XINT | __XWORD | BIT | BOOL | BYTE | DATE | DATE_AND_TIME | DINT | DT | DWORD | INT | LDATE | LDATE_AND_TIME | LDT | LINT | LREAL | LTIME | LTOD | LWORD | REAL | SINT | TIME | TOD | UDINT | UINT | ULINT | USINT | WORD
The keywords T, TIME_OF_DAY and DATE_AND_TIME are alternative forms for the data types TIME, TOD, and DT. T, TIME_OF_DAY and DATE_AND_TIME are not represented as a type conversion command.
The rounding logic for borderline cases depends on the target system or the FPU (Floating Point Unit) of the target system. For example, a value of -1.5 can be converted differently on different controllers.
Catch value ranges overflows across the application to program code-independent from the target system.
If the operand value for a type conversion operator is outside of the value range
of the target data type, then the result output depends on the processor type and
is therefore undefined. This is the case, for example, when a negative operand value
is converted from LREAL to the target data type UINT.
Information can be lost when converting from larger data types to smaller data types.
String manipulation when converting to STRING or WSTRING
String manipulation when converting to STRING or WSTRING
When converting the type to STRING or WSTRING, the typed value is left-aligned as a string and truncated if it is too long. Therefore,
declare the return variable for the type conversion operators <>_TO_STRING and <>_TO_WSTRING long enough that the string has enough space without any manipulation.
⮫ “Conversion: DATE, DT, TOD, LDATE, LDT, LTOD”