Programming Languages
Structured Text
Structured Text is a helpful tool. Especially programmers coming from the PC world will enjoy
this tool. If they program carefully and think about the way of working by PLC, they will be glad
with this editor.
The Structured Text editor is compatible to the IEC 61131-3, all requirements are fulfilled.
An example of Structured Text programming is given in chapter 16.
3.3.2
Graphic Editors
Ladder Diagram
A Ladder Diagram consists of input contacts (makers and breakers), output coils, function
blocks and functions. These elements are connected with horizontal and vertical lines to create
circuits. The circuits always begins at the bus bar (power bar) on the left.
Functions and function blocks are displayed as blocks in the diagram. In addition to the normal
input and output parameters, some blocks also have a Boolean input (EN = ENable) and output
(ENO = ENable Out). The status at the input always corresponds to that at the output.
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Example of a MELSEC Network
Example for Structured Text
Example for Ladder diagram
Programming
MITSUBISHI ELECTRIC