PLC Programming

What is What in CoDeSys
Example of a network in the Function Block Diagram
For further information on the FBD editor see Chapter 5.4.1.
2.2.5 The Continuous Function Chart Editor (CFC)...
The continuous function chart editor does not operate like the function block diagram FBD with
networks, but rather with freely placeable elements. This allows feedback, for example.
For further information on the CFC editor see Chapter 5.4.4.
Example of a network in the continuous function chart editor
2.2.6 Ladder Diagram (LD)...
The Ladder Diagram is also a graphics oriented programming language which approaches the
structure of an electric circuit.
On the one hand, the Ladder Diagram is suitable for constructing logical switches, on the other hand
one can also create networks as in FBD. Therefore the LD is very useful for controlling the call of
other POUs.
The Ladder Diagram consists of a series of networks. A network is limited on the left and right sides
by a left and right vertical current line. In the middle is a circuit diagram made up of contacts, coils,
and connecting lines.
Each network consists on the left side of a series of contacts which pass on from left to right the
condition "ON" or "OFF" which correspond to the Boolean values TRUE and FALSE. To each contact
belongs a Boolean variable. If this variable is TRUE, then the condition is passed from left to right
along the connecting line. Otherwise the right connection receives the value OFF.
Example of a network in a Ladder Diagram made up of contacts and coils
For further information on the LD editor see Chapter 5.4.2.
CoDeSys V2.3 2-21