Ladder Logic Plc Programming Languages

Ladder diagram ld programming.

Ladder logic plc programming languages.

Generally the ladder diagram is most popular all over the world including. Part 3 of iec 61131 deals with basic software architecture and programming languages of the control program within plc. This iec standard allows some ground rules that standardize plc s and their languages. Ladder logic is a graphical based industrial programming language used to program and configure programmable logic controllers or plc s.

The most commonly used plc programming language is the ladder logic diagram. Ladder logic is widely used to program plcs where sequential control of a process or manufacturing operation is required ladder logic is useful for simple but critical control systems or for reworking old hardwired relay circuits. And it is one of the oldest programming languages for plc. As programmable logic controllers became more sophisticated it has also been used in very complex automation systems.

Once compiled and downloaded to a plc the ladder program is scanned like a book. Before programmable logic controllers manufacturing plants employed relay based circuitry to energize different loads based on how the relays were wired together. 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. Ladder programs consist of rungs that house instructions.

The reason for its popularity is that relay logic diagrams were closely resembled by the ladder logic diagrams. There are 5 languages that are all a part of the iec international electrotechnical commission section 61131 3 standard. 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. When the plc was invented designers found a way to use the existing knowledge of the relay control system designers for programming the plc.

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. Ladder logic is one of the top 5 most popular types of plc programming languages used in manufacturing environments. One of the best visual programming languages is a plc programming language called ladder logic or ladder diagram ld. It is used with programmable logic controllers.