Technical Reference Manual - InduSoft

Overview of VBScript
operator. It does not compare objects or their values; it checks only to determine if two object references refer
to the same object.
Logical Operator NOT
The logical operator NOT behaves differently in VBScript than it does in the built-in scripting language.
NOT Operator in VBScript
In VBScript, the NOT operator inverts the bits of a given numeric value, producing its complement number
according to the "two's complement" system of signed numbers that is used by computers. The table below
illustrates the behavior of the NOT operator in VBScript for the syntax…
result = NOT expression
If expression is…
Then result is…
−3 2
−2 1
−1 0
0 −1
1 −2
2 −3
3 −4
Note: By default, when you attempt to write any numeric value other than 0 to a Boolean tag, the
tag automatically assumes a value of 1. Therefore, if VBScript's NOT operator is applied to a Boolean
tag with a value of 1, then the value of the tag does not change; the operator returns a value of −2,
but the tag cannot accept this value so it again assumes a value of 1.
You can configure IWS to treat Boolean tags like Boolean variables in VBScript, so that the NOT
operator in VBScript will work as expected. For more information, please see Boolean Tags and
Boolean Variables.
NOT Operator in Built-in Language
In contrast, the NOT operator in the Built-in Scripting Language toggles the given numeric value as if it
is a natural boolean. The table below illustrates the behavior of the NOT operator in the Built-in Scripting
Language for the syntax…
result = NOT expression
If expression is…
Then result is…
0 1
≠0 0
Using Conditional Statements
You can control the flow of your script with conditional statements and looping statements. Using conditional
statements, you can write VBScript code that makes decisions and repeats actions. The following conditional
statements are available in VBScript:
• If…Then…Else statement
• Select Case statement
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