Learning how PLCs work is something that will help you determine whether you should improve your knowledge and expertise.
However, when you are doing everything yourself, it is challenging to know where to start, especially since the amount of information is highly overwhelming for both beginners and engineers.
Generally, programmable logic controllers or PLCs are vital industrial computers that come with modular components. Their main goal is to program and control the automation process required for particular manufacturing production.
In most cases, you can find them in industrial plants and factories. They are usually controlling fans, lights, pumps, motors, or circuit breakers, among other things that require automation for a particular industry.
That is the main reason why you should consider enrolling in the Allen Bradley PLC training so that you can increase the learning curve and improve your current engineering status.
The best way to understand the overall importance of programmable logic controllers is by following why they entered the market in the first place.
A Brief History of PLCs
You need to understand that even before PLCs entered the market, people used various ways to handle automation processes. Generally, during the mid-20th century, automation requires electromechanical relay circuits.
The main problem with this particular application was the number of wires, space, and relays that simple automation required, which meant that the expenses were significant.
At the same time, a straightforward process required thousands of relays, and single-issue could stop production and lead to severe expenses.
You should remember that automation relays had magnetic closing and opening as soon as they get electrical contact from the coil.
They are still essential parts of industrial automation, but their design is entirely different, and they act as added features, which are not necessary for the entire process.
That was the reason for the creation of programmable logic controller in 1968 as the replacement to relay circuits in production industries and other plants.
They used a similar perspective and function as relays so that engineers could easily program them, and technicians use them without learning new information.
You just had to understand the control schematics as well as relay logic, which was necessary for an engineering career. Therefore, every single engineer could operate these machines by using ladder logic that mimicked control circuit schematics.
Remember that ladder diagrams were similar to control circuits, especially since the power flew from left to right with the idea to energize the relay coil, which was the same perspective as before but with more significant efficiency.
If you already know the control circuit schematics, you will quickly learn ladder logic, primarily since it features pushbuttons, switches, as well as proximity sensors from left as well as output sources from the right based on the energy flow.
On the other hand, when compared with relays, it could control complex automation processes. At the same time, it used the convenient and simple-to-use interface, which was much more suitable for the entire industry.
Of course, the first ones had limited speed and memory capabilities, but as time went by, the features improved. So today, you can quickly get the simplified and small programmable logic controller that will handle any automation process that you wish to implement.
As soon as you check here, you will be able to learn everything about programmable logic controllers.
How Do They Operate?
Similarly, as we have mentioned above, programmable logic controllers are small computers that feature components that will help you control the automation processes based on the programming.
Generally, they are both powerful and simple computers that are essential for every single industry in today’s world.
By using simple terms, we can say that PLC gets the inputs, performs the programming logic inside the processor or CPU, and then it gets to output to send the signal based on the logic you implemented beforehand.
For instance, the washing machine or dishwasher features the programmable logic controller inside that handles the entire process.
Generally, they feature inputs and outputs as well as CPU that will use the particular input and convert it back into the output so that you can get the desired function.
When it comes to inputs, the dishwasher features door switch, water sensors as well as buttons that you will use to program it. On the other hand, the outputs include heat elements, water valves, and pumps.
Therefore, when you push a button, you will activate the input, and CPU inside will detect it based on the programming you implemented. The CPU will verify that you pushed the button, that the doors are closed, which means that it will detect all inputs before leading to outputs.
Finally, when the inputs are finished, the valve will open, fill the water, which is the activated output based on the programming or buttons you pushed.
The sensors inside will detect the amount of water inside, which is another input process, and that will lead to closing the valve and stopping the water flow, which is the output.
The next step includes turning on the heating element depending on your programming, which involves the output. At the same time, the input will control the temperature until it reaches the proper mark you implemented while programing it.
As soon as the water reaches the desired temperature, the soap dispenser will open, and the pumps will turn on along the way.
The logic timer will activate by using the CPU and will wait until everything is clean. Then, it will open the valve, place the rinse water inside and wait until it reaches the lowest levels to release the door lock, which will allow you to handle the entire process.
As you can see, the PLC requires programming beforehand, in which it will use the combination of inputs and outputs to handle the process as well as CPU or processor to act as the brain of these processes that will provide you perfect automation.