PLC LANGUAGES

IEC 1131-3 is the International Standard for Programmable Controller Programming Languages. One of the primary benefits of the standard is that it allows multiple languages to be used within the same programmable controller. This allows the program developer to select the language best suited to each particular task.


 The following is a list of programming languages specified by this standard:

• Ladder diagram (LD)

• Structured Text (ST)

• Function Block Diagram (FBD)

FBD is another graphical programming language. The main concept is the data flow that start from inputs and passes in block(s) and generate the output.

• Sequential Function Charts (SFC)

SFC have been developed to accommodate the programming of more advanced systems. These are similar to flowcharts, but much more powerful. This method is much different from flowcharts because it does not have to follow a single path through the flowchart.

• Instruction List (IL)