• Scripts Page

• The Scripts page has six areas.

• Script Editor box: Shows the script you are writing.

• Script State: Select to send the state of the script to a Wonderware Historian Server historian, the ArchestrA historian.

• Basics area: Provides a location in which you set the expression, triggering conditions, and other settings that run the script in the run-time environment. This area includes:

• Declarations area: Provides a place to add variable declaration statements, such as DIM MyArray[1] as FLOAT;. These declared variables live from the startup to the shutdown of the object and can be used to hold values that persist from one execution of the script to the next. They apply only to the script in which they are declared.

• Aliases area: Lets you create and modify aliases that apply to the script you are working on. Aliases are logically descriptive names for typically long ArchestrA reference strings that you can use in the script to make the script more readable.

• Configure Execution Order: Sets the execution order of multiple scripts (inherited and local) associated with this object.

• Inherited scripts name list: Shows all scripts associated with the object's parent. The columns indicate which kind of trigger the script uses: Startup, On Scan, Execute, Off Scan and Shutdown.

• Scripts list: Shows all scripts currently associated with the object. The columns indicate which kind of trigger the script uses: Startup, On Scan, Execute, Off Scan and Shutdown. Click the Add button to add a new script.

• Script Execution Types

• A script is added to an Object (template or instance) using the ArchestrA IDE. The script related information is edited via the script editor. The editor exposes five script types:

• Startup: Called when the object is loaded into memory (deployment, platform or engine start). This script method is intended to be used to instantiate COM objects and .NET objects. Depending on load and other factors, it may be possible that sets to object attributes from this script method may fail. Attributes that reside off-object are not available to this script method. Therefore it is not recommended to use this script method for any scripting beyond its intended use.
• OnScan: Called the first time an AppEngine calls this object to execute after the object scan state is changed to OnScan. This script method is intended to be used to initiate local object attribute values, or to provide more flexibility in the creation of .NET or COM objects. Attributes that are off- engine are not available to this script method. It is not recommended to use this script method for any scripting beyond its intended use.
• Execute: Called every time the AppEngine performs a scan and the object is OnScan. The execute script method is the workhorse of the scripting methods. This is the place that runtime scripting should be done to ensure that all attributes and values are available to the script. This script method in analogous to the InTouch scripts with the following conditional trigger types:
• On True: Executes if the expression validates from a false on one scan to a true on the next scan.
• On False: Executes if the expression validates from a true on one scan to a false on the next scan.
• While True: Executes scan to scan as long as the expression validates as true at the beginning of the scan.
• While False: Executes scan to scan as long as the expression validates as false at the beginning of the scan.
• Periodic: Executes whenever the elapsed time evaluates as true.
• Data Change: Executes when there is a change in data from one scan to the next.
• Quality changes: When the DataChange Trigger type is selected, the Quality changes checkbox enables. Select this box to trigger the script to run when the Quality of the Expression value changes. In this configuration the script will run whether or not the Expression value changes.
• Deadband: When the DataChange Trigger type is selected, Deadband specifies the amount the expression value must change before the script is executed.
• OffScan: Called when the object is taken OffScan. Primarily used to clean up the object and account for any needs that should be addressed as a result of the object no longer executing.
• Shutdown: Called when the object is about to be taken out of memory, usually as a result of the AppEngine stopping. Primarily used to destroy COM objects and .NET objects and clean up memory.

• QuickScript.NET Operations that Require 1 Operand

• QuickScript.NET Operations that Require 2 Operands

• QuickScript.NET Precedence of Operators

• The following list shows the order of precedence for evaluation of operators. The first operator in the list is evaluated first, the second operator is evaluated second, and so on. Operators in the same line in the list have equivalent precedence. Operators are listed from highest precedence to lowest precedence.

• QuickScript.NET Control Structures

1. QuickScript.NET provides four primary control structures in the scripting environment:
2. IF ... THEN ... ELSEIF ... ELSE ... ENDIF
3. FOR ... TO ... STEP ... NEXT Loop
4. FOR EACH ... IN ... NEXT
5. WHILE Loop

1.  IF … THEN … ELSEIF … ELSE … ENDIF Loop

The IF-THEN-ELSE-ENDIF statement is used to conditionally execute various instructions based on the state of an expression. The syntax is as follows:

IF <boolean_expression> THEN
[statements] [ { ELSEIF
[statements] } ] [ ELSE
[statements] ]
ENDIF;

        2.  FOR … TO … STEP … NEXT Loop