You may use floating point types when defining the variables in an ST program. The floating point types specify the range of values that is permitted for a variable.
There are two types of floating point:
| Floating Point Type | Bits | Range |
|---|---|---|
|
REAL (Real numbers) |
32 |
±10±38 |
|
LREAL (Long real numbers) |
64 |
±10±308 |
NOTE: REAL values have a precision of 1 in 223. LREAL values have a precision of 1 in 252.
When you add floating point values to your Logic programs, you need to use a suitable type of floating point value. You should consider the possible range of numbers, then use the table above to determine which type of floating point value can cover the expected range.