NOTE: Tags do not apply to Template expressions, instead you use Template Parameters.
As you create your own expressions, you will need to reference the values that are stored in the database, methods for items, SCADAPack ES registers, and so on.
Before you enter a reference in an expression, you should familiarize yourself with Relative and Absolute References. When you understand the difference between a relative reference and an absolute reference, you can begin to enter references in your expressions.
When you include a reference in an expression, the referenced value is used to determine the result. For example, an expression that uses the IIF function could contain a reference to a point's CurrentState property—the point's current state value affects the outcome of the expression.
For many types of reference, you can use the browse button of the relevant Expression editor to enter a tag or you can enter the reference manually. However, some types of reference can only be entered manually.
If you want to alter a reference or you want to enter a reference manually, you have to use the correct syntax. The syntax varies according to the type of reference being made. The topics in this section explain how to enter the various different types of reference. For more information, see the topics that are listed in the gray footer section at the bottom of this topic. Select the relevant entry to display the topic that you require.
For information on entering a color, see RGB.
Before you enter a tag, you need to know where your expression will be evaluated. Expressions that are evaluated at the server can only include references to database items that are stored on the same server. For more information, see Evaluation of Expressions.