Programming options
5.3 Powerful and easy-to-use instruction set
Easy Book
Manual, 05/2009, A5E02486774-01
57
5.3
Powerful and easy-to-use instruction set
5.3.1
Easy-to-use programming languages
You have the option of choosing either the LAD (ladder logic) or FBD (Function Block
Diagram) programming language.
LAD is a graphical programming language. The representation is based on circuit diagrams.
To create the logic for complex operations, you can insert branches to create the logic for
parallel circuits. Parallel branches are opened downwards or are connected directly to the
power rail. You terminate the branches upwards. LAD also provides "box" instructions for a
variety of functions, such as math, timer, counter, and move.
The elements of a circuit
diagram (such as normally
closed contacts, normally
open contacts, and coils)
are linked to form networks.
Consider the following rules when creating a LAD network:
●
Every LAD network must terminate with a coil or a box instruction. Do not terminate a
network with either a Compare instruction or an Edge-detection (Positive-edge or
Negative-edge) instruction.
●
You cannot create a branch that could result in a power flow in the reverse direction.
+
*
(
)
&
'
=
%
$
●
You cannot create a branch that would cause a short circuit.
&
=
%
$