The 5 most popular types of PLC Programming Languages are:

1. Ladder Diagram (LD)
2. Sequential Function Charts (SFC)
3. Function Block Diagram (FBD)
4. Structured Text (ST)
5. Instruction List (IL)

👉Ladder diagram is the universal programming language of  PLC. It has a short abbreviation as LD and also known as Ladder Logic. It is used with programmable logic controllers. And it is one of the oldest programming languages for PLC.


👉 Instruction List (IL)

Instruction List (IL) is another type of PLC programming language. It uses the mnemonic code. So the syntax of this programming language is easy to remember.


Advantages of IL:

•    It has a high execution speed.
•    It takes less memory as compared to other programming languages.

👉 Structured Text (ST)

Structured Text PLC language is shortly denoted by the ‘ST’ and ‘STX‘. It uses high-level programming language syntax.

The syntax of ST is similar to the syntax of a high-level programming language with loops, variables, conditions, and operators.

Advantages of ST:

•    ST is very easier to understand for both novice and experienced programmers.

•    Because of its standard coding format, it is easy to edit and modify program written in ST language.

👉 Function Block Diagram (FBD)

Function block diagram (FBD) is a popular and easy way to write a program like a Ladder Diagram.

FBD is represented as a box that consists of a number of lines of code for putting different programming functions.

It is a graphical language for programming logic controller. So, it makes your job easy to describe a system.



👉Sequential Function Charts (SFC)

Sequential function charts (SFC) is also a graphical programming language. It is not a textbase. It has become a popular method of accurately specifying sequential control requirements.
The main function of SFC is only the active parts of the code are executed. Due to this, it makes easier to troubleshoot and to change the code if problems occur.
These languages are accepted internationally. Among all of them, mostly the Ladder diagram (LD) programming language is used in the industry.