Programming a programmable logic controller (PLC) is an important start to achieving functional and scalable industrial automation. The flexibility, durability and performance needs of current modern manufacturing result in Omron PLCs being the most popular choice across many industries. Omron's major advantage is it will run several programming languages, meaning engineers and integrators operating any of our PLCs can choose the best fit for their application.
Here are five programming languages supported by Omron PLCs, and the value of each of them in their contexts.
Structured Text (ST)
Structured Text (ST) is a high-level, text-based programming language. It is great for complex control logic, data processing and mathematical control tasks. It is commonly selected by engineers and software developers with need for more operational control than graphical programming languages may offer.
ST has modular structure which keeps code better organized, is better suited for loops, conditional logic, and custom algorithms when compared to other languages. It is not as visually intuitive as graphical languages but offers clarity and precision, thus making it an ideal language for advanced applications.
Ladder Diagram (LD)
Ladder Diagram (LD) is still one of the most common PLC languages, especially for electrical and automation engineers. The appearance of an LD is similar to electric relay logic circuits, in that the ladder uses symbolic “rungs” between two vertical power rails.
LD is straightforward to understand, readable to the eye and is used for a great deal of on/off control, sequential operations, and various logic controls. LD is usually the easiest for technicians to learn to debug; they understand traditional control panels, many of which illustrate controls in various forms of LADDER SYMBOLS
Function Block Diagram (FBD)
Function Block Diagram (FBD) is a graphical language in which the control logic is developed using connected blocks, which represent functions or operations. This visual way of representing data flow is appropriate for partitioning complex control systems into logical blocks.
Omron PLCs utilize FBD in applications that benefit from reusable code or logically grouped functions, and / or displaying operations or functions where a more circuit-like view of the behaviors of the system is helpful. FBD is typically more useful in automation that processes and controls analog signals and PID loops.
Sequential Function Chart (SFC)
Sequential Function Chart (SFC) gives designers another means to develop their operations by breaking down operations into a series of steps or states of being, as seen in our previous logic symbol flowchart. SFC is a great means of laying out operations, for example, in systems where the process sequence is very important, or where the system machine cycles based on events state changes.
SFC provides clarity in terms of what happens in all aspects of a process, so planning for a process and troubleshooting a process are simpler to perform. Omron PLCs provide full support for SFC, to allow you to visualize your workflows and also make sure the automation happens in the correct sequence.
Instruction List (IL)
Instruction List (IL) is a low-level, text-based language that looks an awful lot like some one-offs assembly code. IL has more or less been under the surface with newer standards (like IEC 61131-3), and only a few legacy systems and/or applications may still be able to use IL.
IL may provide the utmost level of control, however, readability is sacrificed. IL is typically used for very specialized, or very resource-demanding tasks, and thus usually, only when direct efficiency, and control of machine resources is the primary consideration, and not always clear.
Selecting Your Omron PLC With The TopAutoDevice
Since Omron PLC's provide great support for nearly all programming languages (specifically IEC61131-3 component languages), it gives you the opportunity to develop your skills either in a hands-on way or as a profession because Omron PLCs will always allow you to apply, with little extra effort, automation solutions to simply do logical control or support nearly any data manipulations.
At TopAutoDevice, we are proud to carry a selection of Omron PLC models formatted for all three of those languages in the selection. You can find the right product for your project, whether large or small, simple or complicated.
You can check out our Omron PLC series, as well as other brands of automation like Siemens, Schneider and Allen-Bradley. If you are looking for a model to start from, we recommend the Omron CP1H or NJ series as they are flexible and have a trusted track record with designers worldwide.
Final Thoughts
The programming language you choose for your PLC will impact how well your automation system runs, and how easily it can be scaled or maintained. With Omron PLCs, and the support of TopAutoDevice, you are capable of building systems that fulfill the technical requirements, and hopefully accommodate future expansion.
