XOR4

FUNCTION "XOR4" : BOOL
TITLE = 4 way XOR - OON
{ S7_Optimized_Access := 'TRUE' }
AUTHOR : MSKRAM
VERSION : 0.1
//One and Only One
   VAR_INPUT
      IN1 : BOOL;
      IN2 : BOOL;
      IN3 : BOOL;
      IN4 : BOOL;
   END_VAR

   VAR_OUTPUT
      MoreThanOne : BOOL;   // More than one active inputs
      ActiveInputs : USInt;   // Number of active inputs
   END_VAR

   VAR_TEMP
      usiCount : USInt;
   END_VAR


BEGIN
    #usiCount := 0;

    IF #IN1 THEN #usiCount += 1; END_IF;
    IF #IN2 THEN #usiCount += 1; END_IF;
    IF #IN3 THEN #usiCount += 1; END_IF;
    IF #IN4 THEN #usiCount += 1; END_IF;

    #ActiveInputs := #usiCount;
    #MoreThanOne := #usiCount > 1;
    #XOR4 := (#usiCount = 1);

END_FUNCTION