LN (Natural Logarithm)
| Function name | LN_010 |
|---|---|
| Function version | 1.0 |
| Function state | stable |
| Compatibility with IEC61131-3 | compatible |
Graphic symbol :
Input / Output :
| Name | Belonging Group | Access | Types of data | Description |
|---|---|---|---|---|
| EN | Left Power Flow | IEC1131-3 enable input | ||
| A | Normal | R , RW | F , B , W , L , S | Input variable A |
| Q | Normal | W , RW | F , B , W , L , S | Result of the operation Q = ln (A) |
| ENO | Right Power Flow | IEC1131-3 enable output |
Description :
The Logarithm in natural base calculates the logarithm in natural base of the value in A and place the result in Q. The eventual overflow in the result is ignored.
The logarithm in natural base of number less or equal to zero is not an error, but calculates Q equal to 256 for Q of type flag, byte, word and long; for Q of type float Q is –3,404823466e+038