Introduction

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

Representation

Representation of an FBD section:

Objects

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

  • Elementary Functions (EFs),

  • Elementary Function Blocks (EFBs)

  • Derived Function Blocks (DFBs)

  • Procedures

  • Subroutine calls

  • Jumps

  • Links

  • Actual Parameters

  • Text objects to comment on the logic

Properties

FBD sections have a grid behind them. 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).

The program can be entered using the mouse or the keyboard.

Input Aids

The FBD editor offers the following input aids:

  • Toolbars for quick and easy access to the desired objects

  • Syntax and semantics are checked as the program is being written.

    • Incorrect functions and function blocks are displayed in blue

    • Unknown words (e.g. undeclared variables) or unsuitable data types are marked with a red wavy line

    • Brief description of errors in the Quickinfo (Tooltip)

  • Information for variables and pins can be displayed in a Quickinfo (Tooltip)

    • type, name, address and comment of a variable/expression

    • type, name and comment of an FFB pin

  • Tabular display of FFBs

  • Actual parameters can be entered and displayed as symbols or topological addresses

  • Different zoom factors

  • Tracking of links

  • Optimization of link routes

  • Display of inspection windows