Delta Electronics DVP15MC11T Operation Manual page 162


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 -π/2 if the input value of In is -∞. The output value of Out is π/2 if the input

value of In is +∞.

Programming Example

The data types of variables ATAN_In and Out1 are REAL and LREAL respectively. The value of
Out1 is 0.785398163397448 if the value of ATAN_In is 1.0 when ATAN_EN changes to TRUE. The
value of Out1 is -0.785398163397448 as ATAN_In is -1.0.

Variable 1
Variable name
ATAN_EN
ATAN_In
Out1

Variable 2
Variable name
ATAN_EN
ATAN_In
Out1

The program
Data type
BOOL
REAL
LREAL
Data type
BOOL
REAL
LREAL
1
ATAN
ATAN_EN EN E NO
ATAN_In I n O ut Ou t1
Chapter 8 Logic Instructions
Current value
TRUE
1.0
0.785398163397448
Current value
TRUE
-1.0
-0.785398163397448
8_
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