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 TRUNC automatically replaced by 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.
Examples
ST
diVar := TRUNC(1.9); (* Result: 1 *) diVar := TRUNC(-1.4); (* Result: -1 *)