If

Determines whether the contents of numExpression are logically true, then returns the value of numThen or optNumElse accordingly.

Function	Group	Execution	Windows	Embedded	Thin Client
If	Logical	Synchronous	Supported	Supported	Supported

Syntax

If( numExpression, numThen, optNumElse )

numExpression: Tag or expression used as the condition in the function.
numThen: Tag or expression used if the condition is logically true.
optNumElse: Optional tag or expression used if the condition is logically false.

Returned value

`numThen`	If the `numExpression` is logically true.
`optNumElse`	If the `numExpression` is logically false.
No value returned	If the `numExpression` is logically false and there is no `optNumElse` in the function.

Notes

The numExpression parameter can be a combination of logic statements (AND, OR, and NOT). For example, If(TagA>TagB AND TagA=10,1,0).

The numThen parameter can be another function, including the If() function. Therefore, you can use If() functions in cascade. For example, if(TagA>TagB,If(TagA<TagC,1, 2),3).

Examples

Tag Name	Expression
Tag	`If( 5 > 4,10, 6 )` // Returned value = 10
Tag	`If( 5 < 2, 0, 2 )` // Returned value = 0
Tag	`If( 3 = 9, 67 )` // No Returned value. (Tag retains previous value.)