Chapter 8 Logic Instructions
8-81
FC
ABS finds the absolute value of an integer or a real number.
Parameters
Meaning
Description Valid range
In
Number to
process
Input Number to process
Depends on the data type of
the variable that the input
parameter is connected to.
Out Absolute value Output
Absolute value of In
Depends on the data type of
the variable that the output
parameter is connected to.
Boolean
Bit string Integer
Real
number
Time, date
String
BOOL
BYTE
WORD
DWORD
LWORD
USINT
UINT
UDINT
ULINT
SINT
INT
DINT
LINT
REAL
LREAL
TIME
DATE
TOD
DT
STRING
In
● ● ● ● ● ● ● ● ● ● ● ● ● ●
Out
● ● ● ● ● ● ● ● ● ● ● ● ● ●
Note:
The symbol ● indicates that the parameter is allowed to connect to the variable or constant of the data
type.
Function Explanation
ABS finds the absolute value of the input parameter In.
The result is output to Out. That is, Out = | In |.
The input variable and output variable are allowed to be of different data types in this instruction.
When the data types of input and output variables are different, the range of the data type of the
output variable must include the valid ranges of data types of all input variables. Otherwise, there
will be an error during the compiling of the software.
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.
Programming Example
The data types of variables ABS _In and Out1 are both INT and the value of ABS _In is -10. The
value of Out1 is 10 when ABS _EN changes to TRUE. The value of Out1 is 20 as ABS_In is 20.