The IEC operator is used for converting the REAL data type into the DINT data type. CODESYS takes only the integer part of the number.
In CODESYS V2.3 Gateway Server, the TRUNC operator converts REAL into INT. If you import a V2.3 project, then CODESYS automatically replaces TRUNC with TRUNC_INT.
If CODESYS cannot represent the input value by a DINT or INT, then the result of this function is undefined. The behavior of such input values
is platform-dependent.
NOTICE
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.
Examples
Result in diVar: 1
ST
diVar := TRUNC(1.9); (* Result: 1 *) diVar := TRUNC(-1.4); (* Result: -1 *)