Delta Electronics DVP15MC11T Operation Manual page 164


Users can choose different data types for the input parameter in this instruction. But the data type of
the output parameter is restricted to LREAL. An error will occur during the compiling of the software
if the data type of the output parameter is not LREAL.

Precautions for Correct Use

The input variable is not allowed to omit. An error will occur during the compiling of the software if
the input variable is omitted. But the output variable is allowed to omit.

The output value of Out is nonnumeric when the input value of In is a non-positive number as shown
in the following table.
The variable table and program
Variable name
LN_EN
LN_In
Out1

Programming Example

The data types of variables LN_In and Out1 are INT and LREAL respectively. The value of Out1 is
0.0 if the value of LN_In is 1 when LN_EN changes to TRUE. The value of Out1 is
1.00000005734143 as LN_In is 2.718282.

Variable 1
Variable name
LN_EN
LN_In
Out1

Variable 2
Variable name
LN_EN
LN_In
Out1

The program
Data type
BOOL
REAL
LREAL
1
LN
L N_ EN E N ENO
LN_In In O ut
Data type
BOOL
INT
LREAL
Data type
BOOL
REAL
LREAL
1
LN
L N_ EN E N ENO
LN_In In O ut Out 1
Chapter 8 Logic Instructions
Current value
TRUE
-2.0
1.#QNAN
Out 1
Current value
TRUE
1
0.0
Current value
TRUE
2.718282
1.00000005734143
8_
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