Expression Editor elements

• Select Property pane

  The Select Property pane displays a hierarchical view of the properties that you can insert into expressions. For historized items, only properties that are streams are available in the Select Property pane. You can expand each node to reveal its available properties, which the icon indicates. Double-click a property in the Select Property pane to insert it into the edit box where you place the insertion point.

• Parameters pane

  The Parameters pane displays parameters that Production Management makes available to insert into expressions. Different parameters are available depending on the item for which you build the expression. When you double-click a parameter, AVEVA™ Production Management inserts it into the expression where you place the insertion point.

• Expression tab

  The Expression tab contains the Expression Edit box to display and edit the expression, the Expression toolbar to insert C# operators into an expression, and a Compile check box to select to have AVEVA™ Production Management compile the expression.

• Expression Edit box

  The Expression Edit box displays the expression for edit. It is a C# code editor with code coloring to edit a single line of C# code. You can type the expression directly into the edit box, or you can insert properties from the Select Property pane, insert parameters from the Parameters pane, and insert operators from the Expression toolbar to build the expression.

• Expression toolbar

  Use the Expression toolbar to insert C# operators into the expression that you build in the Expression Edit box. AVEVA™ Production Management inserts an operator where you place the insertion point.

• Filter check box

  The Filter checkbox enables you to filter out bad or uncertain data in expressions. This enables your reports and graphs to represent data that is of good quality only. Any bad or uncertain data encountered is replaced by the last known good value.

  

  The default value for this check box is to not filter. Select the Filter check box in every expression that you want filtered.

  Quality of Data	in stream viewer
  Good	Green
  Bad	Red
  Uncertain	Yellow

• Compile check box

  Select the Compile check box to make the expression available for AVEVA™ Production Management to compile. If you do not want the expression available for AVEVA™ Production Management to evaluate, clear the Compile check box.

• Dependencies tab

  This tab contains the Dependencies List box that displays the dependencies for the expression and the Remove Button to remove selected dependencies. The icon indicates a dependency.

• Dependencies List box

  The Dependencies List box displays the dependencies for the expression, and it can contain any number of dependencies. Multiple dependencies behave like a logical OR list; that is, each dependency can trigger AVEVA™ Production Management to evaluate the expression.

  Double-click a property in the Select Property pane to add a reference to it in the Dependencies List box. You cannot edit dependencies in the list box.

• Remove button

  Click Remove to delete selected dependencies from the Dependencies List box.

Related topics

• About expressions

• Build an expression

• Working with data