Use logical operators
Use logical operators to verify if multiple conditions are true or false. The result of a logical operation is a BOOL value.
If the comparison is | The result is |
true | 1 |
false | 0 |
Use these logical operators.
For this comparison | Use this operator | Optimal data type |
logical AND | &, AND | BOOL |
logical OR | OR | BOOL |
logical exclusive OR | XOR | BOOL |
logical complement | NOT | BOOL |
The table provides examples of using logical operators.
Use this format | Example | |
For this situation | Use | |
BOOLtag | If photoeye is a BOOL tag and your specification says: "If photoeye_1 is on then..." | IF photoeye THEN... |
NOT BOOLtag | If photoeye is a BOOL tag and your specification says: "If photoeye is off then..." | IF NOT photoeye THEN... |
expression1 & expression2 | If photoeye is a BOOL tag, temp is a DINT tag, and your specification says: "If photoeye is on and temp is less than 100 then..." | IF photoeye & (temp<100) THEN... |
expression1 OR expression2 | If photoeye is a BOOL tag, temp is a DINT tag, and your specification says: "If photoeye is on or temp is less than 100 then...". | IF photoeye OR (temp<100) THEN... |
expression1 XOR expression2 | If photoeye1 and photoeye2 are BOOL tags and your specification says: "If: photoeye1 is on while photoeye2 is off or photoeye1 is off while photoeye2 is on then..." | IF photoeye1 XOR photoeye2 THEN... |
BOOLtag := expression1 & expression2 | If photoeye1 and photoeye2 are BOOL tags, open is a BOOL tag, and your specification says: "If photoeye1 and photoeye2 are both on, set open to true" | open := photoeye1 & photoeye2; |
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