XOR block

Short summary

Name	`XOR`
→POU type	→function
Category	IEC-block, Bitstring
Conform to →IEC-standard	no restrictions
Graphical interface
Available since	version 1.0.0 (for Neuron Power Engineer) – initial variant version 3.2.5 (for library `Standard`) – internal matters refactored in order to prevent warnings when compiling

Functionality

The block returns the result of a bitwise EXCLUSIVE-OR operation of all values connected to the inputs.

According to the table 31 of the →IEC-standard, the behavior of the statement XOR(a,b,c,d) corresponds to the behavior of the statement a XOR b XOR c XOR d. These statements are processed from left to right according to the priority of the operators in ST. Thus, first result = a XOR b is evaluated, then result2 = result XOR c and then endResult = result2 XOR d.

Inputs, return value

	Identifier	→Data type	Description
Inputs:	`IN1`	`BOOL`, `BYTE`, `WORD`, `DWORD` or `LWORD` (corresponds to →generic data type `ANY_BIT`)	1st value
	`IN2`	`BOOL`, `BYTE`, `WORD`, `DWORD` or `LWORD` (corresponds to →generic data type `ANY_BIT`)	2nd value
	... (extensible until)
	`IN16`	`BOOL`, `BYTE`, `WORD`, `DWORD` or `LWORD` (corresponds to →generic data type `ANY_BIT`)	16th value
Return value:	–	`BOOL`, `BYTE`, `WORD`, `DWORD` or `LWORD` (corresponds to →generic data type `ANY_BIT`)

Input EN and output ENO are available when →calling the block. See "Execution control: EN, ENO" for information on input EN and output ENO.

See:

"Blocks for safe logic" whether this block is supported for developing safety-relevant applications.
"Highlighting safe logic in the FBD-editor" for the effects when using the block as a block for safe logic.

Example for usage within ST-editor

PROGRAM Test

VAR

        result1, result2, result3, result4 : BOOL;

    END_VAR

    result1 := XOR(IN1 := FALSE, IN2 := FALSE);       (* The variable 'result1' evaluates to 'FALSE'. *)

    result2 := XOR(IN1 := FALSE, IN2 := TRUE );       (* The variable 'result2' evaluates to 'TRUE'.  *)

    result3 := XOR(IN1 := TRUE,  IN2 := FALSE);       (* The variable 'result3' evaluates to 'TRUE'.  *)

    result4 := XOR(IN1 := TRUE,  IN2 := TRUE );       (* The variable 'result4' evaluates to 'FALSE'. *)

END_PROGRAM

When creating your application within the ST-editor, enter a call of a block by typing the text as requested by the syntax or use Content Assist.