How To Program A PLC

The ABS instruction takes the absolute value of the Source and places the result in the Destination.

Available Languages
-    Ladder Diagram

-    Function Block

-    Structured Text

dest := ABS(source);

Operands
-    Ladder Diagram

Operand	Type	Format	Description
Source*	SINT INT DINT REAL	Immediate tag	value from which to take the absolute value
Destination	SINT INT DINT REAL	tag	tag to store the result

*Data Conversion: SINT and INT tags are sign-extended.
   
-    Function Block

Operand	Type	Format	Description
ABS tag	FBD_MATH_ADVANCED	structure	ABS structure

-    Structured Text
Use ABS as a function. This expression computes the absolute value of source and stores the result in dest.

dest := ABS(source);

FBD_MATH Structure

Input Parameter	Data Type	Description
EnableIn	BOOL	Enable input. If cleared, the instruction does not execute and outputs are not updated. Default is set.
Source	REAL	Value of which to take the absolute value. Valid = any float

Output Parameter	Data Type	Description
EnableOut	BOOL	Enable output.
Dest	REAL	Result of the math instruction. Arithmetic status flags are set for this output.

Example
Place the absolute value of value_1 into value_1_absolute. In this example, the absolute value of negative four is positive four.

-    Ladder Diagram

-    Function Block

-    Structured Text

value_1_absolute := ABS(value_1);

File name: PLC-24_IS_CMI-ABS.pdf
File size: 412.69 KB

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