Welcome to the Guide to Expressions
Welcome to the ClearSCADA Guide to Expressions. This guide explains how to create expressions - combinations of symbols and operators that ClearSCADA evaluates to obtain a single value. Expressions can be used to obtain values for many different aspects of ClearSCADA, including Mimics, Trends, Data Grids, Methods, and Historic calculations.
Intended Audience
This guide is designed for use by engineers who have some programming experience and are responsible for the configuration of expressions in ClearSCADA. The grammar and syntax for expressions are similar to those in other programming languages such as C and Visual Basic.
Document Scope
In this Guide, we explain how to use the expression editors and describe the required syntax for valid expressions in ClearSCADA. This guide is designed for use by engineers that have some programming experience—the grammar and syntax for expressions are similar to those in other programming languages such as C and Visual Basic.
An expression is a combination of symbols and operators that ClearSCADA evaluates to obtain a single value. For example, an expression can be used in the animation for a text box in a Mimic so that the text box displays a different string according to the state of a point. You can use expressions in various parts of ClearSCADA including:
- Mimics
- Trends
- Group Templates (see Define which Property Values Derive from a Group Template )
- Data Grids (see Configuring Data Grids)
- Data Sets (see Configuring Data Sets)
- Methods (see Method Expressions)
- Historic Calculations (see Configuring Historic Calculations)
- Calculation Points (see Configure and Working with Calculation Points).
The main sections in this guide contain details about the syntax and functions for expressions. They also explain how to use the various Expression displays and fields. 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.