The Truncation functions convert real values to integers by rounding to the next integer closest to zero.
You can declare truncation in three different ways:
| Form | Syntax | Description |
|---|---|---|
| Exactly Typed | *_TRUNC_** |
Where * is the type to change from, and ** is the type to change to. For example: REAL_TRUNC_INT( 12.5 ) |
| Overloaded #1 | ANY_TRUNC_** |
Where ** is the type to change to. For example: ANY_TRUNC_INT( 12.5 ) |
| Overloaded #2 | TRUNC_** |
Where ** is the type to change to. For example: TRUNC_INT( 12.5 ) |
The from (*) type can be REAL or LREAL. The to (**) type can be SINT, USINT, INT, UINT, DINT, UDINT, LINT, or ULINT.
Examples of floating point rounding using REAL_TRUNC_INT( X ):
| Floating Point | Rounded Integer Result |
|---|---|
| REAL#3.6 | INT#3 |
| REAL#3.5 | INT#3 |
| REAL#3.4 | INT#3 |
| REAL#2.5 | INT#2 |
| REAL#1.5 | INT#1 |
| REAL#-1.5 | INT#-1 |
| REAL#-2.5 | INT#-2 |
| REAL#-3.4 | INT#-3 |
Table 22.2 - IEC 61131-3 Second Edition.
Table 22.2 - IEC 61131-3 Third Edition.
To learn about the standard elementary data types.
Type CastsTo learn about other methods of converting from real numbers to integers.
For a summary of all conversion functions.
To learn about other common language elements.
For the meaning of terms used in Fernhill SCADA.