With the ecxeption of REAL or LREAL-Constants (in this case, always LREAL is used) the smallest possible data type is used when calculating with IEC constants.
If you want to use a different data type, you can use typed literals to do this without
having to declare the constant explicitly. Provide the constant with a prefix that
defines the type.
Syntax
<type> # <literal>
<type> specifies the desired data type. Possible inputs are BOOL, SINT, USINT, BYTE, INT, UINT, WORD, DINT, UDINT, DWORD, REAL and LREAL. You must capitalize the type.
<literal> specifies the constant. The input must go to the below <type> specified data types match.
Example
diVar := DINT#34;
If CODESYS cannot convert the constant into the target type without data loss, then an error message is issued.
You can use typed constants wherever you can use normal constants.