IEC 61131-3 Scripts

Introduction

Using Fernhill SCADA, you can configure a SCADA system without any requirement to write scripts or code. For example the Configuration Tool allows you to do all of these actions without requiring you to write scripts or code:

Configure tags to represent plant and equipment.
Configure graphics and trends using simple mouse clicks.
Associate tags with graphics and trends using drag and drop.

However you may want to extend Fernhill SCADA beyond its core features. You can use IEC 61131-3 Structured Text (ST) to do this.

Areas where IEC 61131-3 Structured Text (ST) is used to to extend Fernhill SCADA include:

Run an Operator Action, which could be:
- When a user interacts with a Graphic Page, or
- When a user clicks a button on the Operator Toolbar.
Perform a calculation in a Data Binding to transform raw data before it is displayed on a Graphic Page.
Perform a calculation in a Text Report.
Define the action of a Program Tag, which could be used to:
- Define custom event driven scanning.
- Transfer data from a database to a PLC.
- Reflect data between PLCs.
- Apply custom data transformations.
- Execute an SQL statement on the Fernhill SCADA database using a SQLCommand Function Block.
Define the calculation of a Calculated Data Tag.

Authoring Structured Text

You can create structured text programs using:

Structured Text Statements.
Language common elements.
Operator Action Functions - if you are writing a user interface script.

Further Information

Expressions

To learn about the expressions that can be used in calculated tags.

Program

To learn about declaring Programs.

Glossary

For the meaning of terms used in Fernhill SCADA.