• Home
• Function/Function Block Reference
• IEC 61131-3 Functions and Function Blocks
• Numerical and Arithmetic
• LOG

LOG

Type	Function
Description	Calculates the logarithm to the base of 10 of the operand connected to IN1.
Parameters	Input IN1 Data type: ANY_REAL Description: Input value. Output OUT Data type: ANY_REAL Description: Output value.
Error behavior	Error behavior The following table shows the errors which may occur while executing the function and the value returned by the function in the corresponding error case. As described, the value returned by the function in the error case depends on the value of the input (for example, if the input value is not a legal number (NaN), the function returns NaN). Error case Output value 0 Inf- Input value < 0 or Input value = Inf- NaN NaN NaN Inf+ Inf+
Additional information	EN/ENO behavior The POU is only executed if TRUE is applied to the EN input. If EN = FALSE, the POU is not executed and ENO = FALSE indicates the inactivity. If any of the errors listed under "Error behavior" occurs while executing the function, ENO is set to FALSE. Further Info See the topic "General information on execution control with EN/ENO" for further details.