Introduction

The FBD editor is used for graphical function block programming according to IEC 61131-3.

Representation of an FBD Section

Representation:

Objects

The objects of the FBD programming language (Function Block Diagram) help to divide a section into a number of:

• EFs and EFBs (Elementary Functions and Elementary Function Blocks),

• DFBs (Derived Function Blocks),

• Procedures and

• Control Elements.

These objects, combined under the name FFBs, can be linked with each other by:

• Links or

• Actual Parameters.

Comments regarding the section logic can be provided using text objects (see Text Object).

Section Size

One FBD section consists of a window containing a single page.

This page has a grid background. A grid unit consists of 10 coordinates. A grid unit is the smallest possible space between 2 objects in an FBD section.

The FBD programming language is not cell oriented but the objects are still aligned with the grid coordinates.

An FBD section can be configured in number of cells (horizontal grid coordinates and vertical grid coordinates).

IEC Conformity

For a description of the extent to which the FBD programming language conforms to IEC, see IEC Conformity.