VBScript Reference Manual for InduSoft Web Studio

InduSoft Web Studio VBScript Reference Manual
Logical Operators
Logical Operators are used to perform logical operations on expressions, and can also be used as bitwise
operators.
Operators Function Example Returns
And Logical And a AND b True only if a and b are both true
Eqv Logical Equivalent a Eqv b True if a and b are the same
Imp Logical Implication a Imp b False only if a is true and b is false otherwise true
Not Logical Not a Not b True if a is false; False if a is true
Or, | Logical Or a OR b True if a or b is true, or both are true
Xor Logical Exclusive Or a Xor b True if a or b is true, but not both
A word of caution about the NOT operator. The NOT operator inverts
boolean “True” and “False” values as expected. However, the NOT
operator can also operate on other data subtypes and IWS data types. The
chart to the right shows the result of the NOT operation on integer (or Real)
values.
Is Operator
The Is operator is used to compare one object variable to another to determine if they reference the
same object. In addition, the Nothing keyword can be used to determine whether a variable contains a
valid object reference..
$ Operator
NOT of
Expression
Expression
True False
False True
3 -4
2 -3
1 -2
0 -1
-1 0
-2 1
-3 2
The $ operator is a very special operator which has been added by InduSoft. The $ operator allows
VBScript to access IWS tags and built-in functions. IWS tags can be used in expressions similar to
VBScript variables. Remember that IWS variable types can be different that VBScript data subtypes.
When the $ operator is used, Intellisense (part of VBScript) will display all current IWS tags and built-in
functions in a scroll-down menu. The developer can choose from any of these, or add new tags by
typing a unique name. If a new tag name is entered, IWS will then prompt the developer for tag type
specifications.
Example: $Temp1 = 100 ‘ Sets IWS tag Temp1 to a value 100
MsgBox $temp1 ‘ Prints the value of IWS tag Temp1
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