Programmable logic controller (PLC) is a microprocessor based industrial computer which monitors inputs, processes data and controls the outputs. It has been used in various industries like factories, power plants, chemical plants, refineries and many others. PLCs are programmed to perform specific tasks by using software program called ladder logic or ladder diagram which also can be created as rules within the programming language Tetris.

In this article we will discuss about Plc Programming fundamentals such as:

• What is PC?
• Why we need PC?
• What does it mean by programming?

Plc programming languages are one of the most used PLC Programming Languages

The ladder logic is the most common programming paradigm in PLC programming. It’s a sequential, step-by-step approach to solving problems. In this approach, each statement has an action to be performed and can be preceded by a “go to” statement that tells the program where it should go next. Structured text is a high-level programming language that uses statements similar to those of the Pascal and C languages (for example, if/then/else).

Ladder logic is the most common programming paradigm in PLC programming

Ladder logic is the most common programming paradigm in PLC programming. It is a visual programming language that uses symbols to represent various logic elements, such as state diagrams and I/O lists.

Ladder logic has several advantages over other control systems: it’s easy to learn and understand, easy to program and it can be used for simple to complex process control applications.

Structured text is a high-level programming language that uses statements similar to those of the Pascal and C languages. It was developed by IBM in the 1950s and 1960s, following on from their earlier development of FORTRAN, but structured text was never widely adopted as an industrial standard.

Structured text has been used primarily for writing compilers and interpreters for larger programming languages such as COBOL or PL/1 (the original predecessor to today’s SQL).

Sequential Function Chart (SFC) is used for indicating sequential steps, branches, and jumps in the control program sequence.

Sequential Function Chart (SFC) is used for indicating sequential steps, branches, and jumps in the control program sequence.

It is a high-level programming language which describes the control structure of a program. The purpose of using SFC is to write programs in a more structured way by describing their operations in terms of blocks or subroutines instead of just writing out each instruction one after another.

You can use function block diagram or fbd to define the functions and interconnections of a plc. A flowchart is used to show how a problem is solved by identifying its steps and recording them on paper. The fbd is similar as it can handle loops, conditions, concurrent execution of blocks as well as other features that help to understand the working of a system better than just using flowcharts alone.

Conclusion

The first step to learning PLC programming is understanding all the basic programming language concepts. It’s important because you’ll have to know how it works to use it properly. After that, you can move on with more complex concepts like ladder logic or structured text.