Ladder Logic Plc Programming Languages

Once compiled and downloaded to a plc the ladder program is scanned like a book.

Ladder logic plc programming languages. The reason for its popularity is that relay logic diagrams were closely resembled by the ladder logic diagrams. Part 3 of iec 61131 deals with basic software architecture and programming languages of the control program within plc. There are 5 languages that are all a part of the iec international electrotechnical commission section 61131 3 standard. Ladder logic is a graphical based industrial programming language used to program and configure programmable logic controllers or plc s.

Ladder diagram ld programming. It is used with programmable logic controllers. This iec standard allows some ground rules that standardize plc s and their languages. One of the best visual programming languages is a plc programming language called ladder logic or ladder diagram ld.

Generally the ladder diagram is most popular all over the world including. Before programmable logic controllers manufacturing plants employed relay based circuitry to energize different loads based on how the relays were wired together. This is a graphical language showing the logical relationships between inputs and outputs as though they were contacts and coils in a hard wired electromechanical relay circuit. The most common language used to program plcs is ladder diagram ld also known as relay ladder logic rll.

When the plc was invented designers found a way to use the existing knowledge of the relay control system designers for programming the plc. Let s take a deeper look into all these popular plc programming languages. Ladder programs consist of rungs that house instructions. Iec 61131 3 is the third part of 10 of the open international standard iec 61131 for programmable logic controllers and was first published in december 1993 by the iec the current third edition was published in february 2013.

In the ladder diagram the programming language use to create the program to control the plc system is known as ladder diagram language or ladder logic language. And it is one of the oldest programming languages for plc. Ladder logic is one of the top 5 most popular types of plc programming languages used in manufacturing environments. The great thing about ladder logic is that it s much more visual than most programming languages so people often find it a lot easier to learn.