The PLCs are specific computers that are essential for most industries that rely on them for manufacturing processes. It features relay control panels that you have to understand before you enter the industry as an expert.
The best thing that you can do is to consider Allen Bradley RSLogix 5000 training because that is the best way to control the automation and increase your career prospects. We will show you what you can expect by entering the practice:
What Is Programmable Logic, Controller?
PLC, or Programmable Logic Controller, is a digital computer that we can use for automation for various processes both electro and mechanical ones.
These particular controllers can easily withstand harsh conditions and situations because they feature shields from dust, heat, cold and moisture. Therefore, you will get a computer that will increase the overall performance of your industry system.
You should have in mind that programs come from a PC and computer, and later developers download it to PLC by using cable. These programs enter in non-volatile memory of the programmable logic controller. When you create a transition between relay control panels to PLC, the relay logic enter the scene and users feed the program based on the real-time system.
The most famous and used programming language for PLCs is Ladder Logic, and you should continue reading to learn more about it.
History Of PLCs
It all started back in the 20th century when the automotive industry wanted to find an alternative to re-wiring control panel, which used too much time and money. Before the PLC entered the scene, manufacturers used lots of cam timers, relays, and closed-loop controllers.
Therefore, electricians had to re-wire the entire machine on a daily basis which was highly expensive and time-consuming. Soon afterward in 1968, electronic device replaced hard-wired relay systems. The first manufacturer was GM Hydramatic. You can click here to find out more on GM Hydromatic.
The first one is 084 PLC, and it was the project that Dick Morley, father of PLCs, started. One of the largest users of PLCs is the automotive industries.
- CPU – Every PLC controller must contain a CPU that will keep checking it to avoid any technical errors. CPU perform functions such as arithmetic operations, logic operations, computer interface and many more.
- Memory – CPU includes system (ROM) that will store the data inside the operating system. At the same time, RAM will store information of the status of output and input devices, counters, the values of times and other internal devices.
- Input/Output – Output has control over various devices that you connect with PLCs such as pumps, motors, solenoids, and lights. You will get input/output ports installed based on RISC (Reduced Instruction Set Computer). On the other hand, the input will keep track of field devices such as switches and sensors.
- Power Supply – Some PLCs feature separate power supply so that you can use it without thinking of potential breakage and damage. You should have in mind that most of them work at 24 VDC or 220 VAC.
- Programming Device – This particular device is vital to PLC programming because developers use it to feed the program into the memory of CPU. The program will supply the programming device and later enter into PLCs memory, for additional convenience.
Buses are paths in which digital signal will flow internally to reach the programmable logic controller. We can differentiate four system buses:
- First one is a data bus that uses CPU with the idea to transfer data among a wide array of elements.
- Control bus will transfer signals that will relate an action so that you can control it internally
- Address bus can send the location’s addresses that will access the data
- System bus will help input/output ports and units to communicate with each other.
How To Work On PLC?
It is vital to understand how programmable logic controller functions. In most cases, everything happens in three steps:
- Input Scan – You will notice that the machine will scan the state of input externally. This includes push buttons, switches, limit switches, proximity sensors, pressure switches among many others. In the best case scenario, you will have transformers and avoid using relays.
- Program Scan – The developer has to add and load the program that will carry the function you wish to achieve without any additional problem.
- Output Scan – We have mentioned above that input sources have control over output ports. They can easily energize and de-energize them. On the other hand, outputs are valves, solenoids, actuator, motors, and pumps. Of course, everything depends on the model of PLC, but they can be triacs, transistors, and relays.
One of the essential applications of PLCs is a conveyor system. Therefore, you should follow specific requirements so that you can use it with ease:
- It features a programmable logic controller that will help you to start and stop motors in the conveyor belt.
- At the same time, the conveyor system includes three segmented belts, where each segment comprises a motor that will run it and make it work.
- The best way to detect the position of a plate is by checking a proximity switch at the segment’s end.
- You should always turn the first conveyor segment ON.
- The proximity switch will detect the plate with the idea to turn ON the second segment that you wish to follow.
- As soon as proximity switch detects the plate of the second conveyor, the third segment will be turned on automatically.
- When plate gets out the detection range, the second one will stop for about 20 seconds.
Dick Morley is the father of PLCs, and you can create a thorough understanding on what he wanted to achieve by visiting this particular website: https://en.wikipedia.org/wiki/Dick_Morley
Benefits Of PLCs:
- You can easily program it to follow and understands everything you wish to control
- They can survive noise, vibrations, temperature, and humidity
- Most of them include input and output for interfacing and communication between systems
Downsides Of PLCs:
- It is difficult to understand, which is why most people go to training to learn more about it
- It requires a skillful workforce to control it and reduce errors