Elevator control system is needed to control all of the functions of the elevator such as controlling the opening and closing of doors of the elevator at different floor and the safety switches. 

All of the controls are based on the input that is received from the operator as well as from the sensors at every floor.

The uses of PLC helps the elevator control system to become better, faster, stronger and better quality elevators than traditional elevator control systems.

Traditional elevator control system works on the relay logic which has a high failure rate which can causes the electrical contact to burn out easily because of the numerous contacts and complexity of the wiring circuit. 

For controlling the elevator by using PLC, the addition of sensors as input into the PLC is taken. Requirements that are needed such as sensors like IR sensors, oxygen sensor, load cell and so on.

IR sensors are used for detecting objects to prevent the door close when there is a person or any object in between of the door. Load cell is used to measure the weight of the objects in the elevator. Oxygen sensor is the additional feature which is used to give signals when there is an insufficient oxygen occurs. It will takes the objects in the elevator to the nearest floor and open the door automatically. 

PLC provides advantages such as helping to increase comfort level by providing automatic door opening and closing. It is more flexible as easy to reprogram the PLC if in the future we wish any advanced functions with negligible changes.

However, it is more costly as compared to microcontroller based control.

https://www.ijireeice.com/upload/2017/april-17/IJIREEICE%2026.pdf

Manufacturing cement involves mixing various raw materials in a kiln. The quality of these raw materials and their proportions significantly impact the quality of the final product. To ensure the use of the right quality and quantities of raw materials, the accuracy of data regarding such process variables is of the essence.

 

A distributed control system comprised of PLC in its user mode and a configuration software are used in the industry’s production and management processes. The PLC in particular, controls ball milling, coal kiln and shaft kiln.

 

PLC is also used in the coal-fired boiler fan change-over system in hospitals, corrugation machine control system and silo feeding as well as Injection Moulding Control Systems in The Plastic Industry.

 

Control system of The Plastic Injection Machine formed by electric relays and switching valves has many shortcomings, such as complexity wiring, low control accuracy, inconvenience maintenance and lack of flexibility, using the simulation assessment of the actual application method, this paper designs the injection molding machine control systems based on PLC controller, the new control system is composed by PLC, inverter, sensors and other components, with the help of PID control, which according to the given screw barrel temperature deviation value and measured value, automatically adjust and stabilize of the entire control system.

Simulation experimental results show this new control system can achieve better performance is effective, which will decrease energy consumption of the stabilization system; the research achievements have certain theoretical and practical value to the design of injection molding machine control system.

Based on PLC controller, we use PID control to achieve asked achieve control purpose. When injection molding machine starts running, PLC monitoring device first initialize the various production tasks: including temperature setting, the value of the piece is cleared, dwell time setting is cleared, etc,, then PLC controller sends control at a certain timing signal-controlled hydraulic actuator solemoid valves and start the AC ppower regulator AC power regulator to full power output to the heating load, and allow rapid temperature stabilized at the set value, then began to produce the hydraulic drive mechanism the operation steps.

PLCs are being used to help make wind turbines more efficient and experience less downtime. It’s crucial that wind turbines have accurate information regarding wind conditions to operate safely, as wind data is vital to record turbulence and protect the turbine. PLCs convert signals from the wind speed and direction sensors to better control the wind turbines. The data transmitted from the PLCs are also used for statistical analysis to predict failures before they occur.

2. The Smart Factory

The manufacturing process has become a lot more efficient thanks to the Internet of Things (IoT), intelligent automation, advanced robotics and other Smart Factory initiatives. Despite the rapid changes in technology, PLCs continue to play a vital role in manufacturing and act as a central processor for all real time decisions. For instance, a PLC sends robust data, including sensor performance and other data, that can be integrated with cloud computing to show a more holistic picture, i.e. a collection of “big data.” Analysis tools can then help plant managers and others to better leverage resources, batch scheduling of jobs, logistics, supplier timing and other functions that are critical to create more efficient manufacturing processes.

3. Virtual modeling

Plant managers require virtual modelling systems in order to create an accurate floor plan. In doing so, manufacturers can improve their operations across their entire value chain, from design and engineering to sales, production, and service. PLCs can be used in virtual modelling to simulate how a new piece of equipment will perform when installed. That way, manufacturers can make the right adjustments for a successful implementation without resorting to costly changes.

Source: https://www.plctechnician.com/news-blog/Important-Uses-of-PLCs-in-Manufacturing

Industrial Automation uses control devices and systems like robotics and computers to automate industrial machinery and their operations which eliminates the need for human operators. Industrial automation saves time, eliminates human errors, cuts costs and improves performance. Once we program PLCs, they perform events in sequence, triggered by the stimuli called inputs. The inputs are received through time delays or counted occurrences. To keep pace with the increasing demands of industrial standards, PLCs are designed to withstand extreme vibration, heat, humidity, temperatures and noise.

PLCs are of great use in various industries such as automobile industry, steel industry, chemical industry, energy sectors and so on. Based on the technologies followed in industries, the application of PLCs varies. Let us discuss a few industries where PLCs help in automation and control.

Paper Industry
In the paper industry, PLCs are used in various applications including machine control and monitoring. For example, PLC controls and automates the speed of the machine that prints books or offset web pages.

In the travel industry, such as in airports, PLCs are used to operate lifts and monitor safety control systems.

PLCs have been used in the glass industry for decades to control material ratios and to process production of large sheets of glass. PLC is used in both analog and digital mode in the glass industry. Analog mode is used for data recording and digital mode for position and digital quality control.

PLCs are used in injection molding, corrugation machine control applications, silo feeding and coal-fire boiler systems in hospitals.

The important part of quality cement manufacturing involves mixing of correct raw materials in proper proportions. The end product greatly depends on this process of mixing and processing. The distributed control systems using PLC controls ball milling, shaft kiln and coal kiln. The PLC ensures accuracy of data to measure right quantity and quality of raw materials in cement manufacturing.

SOURCE : https://study.com/academy/lesson/programmable-logic-controllers-plc-in-industrial-networks-definition-applications-examples.html

It is difficult to picture our modern world without traffic signals. Those three colored streetlights are used and understood by people all around the world. This simple but ingenious application of the PLC has a long history in major cities and small towns all around the world, since their first application traffic control in 1926 in London, England. These traffic lights, that we take for granted every day are monitored and controlled by PLC hardware and software, running dependably and without fuss 24/7/365 days a year.

Have you ever noticed when you travel at rush hours on a busy street, it is an entirely different experience than at low traffic periods? If a pedestrian pressed the button to cross at an intersection, how does that affect flow of the vehicles? Do traffic lights actually “see” an emergency vehicle and allow it to blaze through an intersection? Using emergency vehicle transponders, sensors, and PLC circuits to control the traffic lights, traffic flow is coordinated and managed to allow for more timely and direct rescue services.

2) The Automatic Car Wash

In any busy metropolis where car traffic is present, there are many gas stations accompanied by automatic or “touch-less” car wash stations. As you take a trip inside the touch-free carwash, you will find the water mixed with cleaning solutions, blasting the surface of the vehicle and spinning wipers for scrubbing. Every process is calculated and carefully controlled, from how many litres/gallons of soap is used, to the length of time those tall rotating wipers spin. These time and work saving services are completely automated by PLCs, with little human interaction other than a press of button at the entrance.

3) The Elevator
The elevator industry is on the rise; pun intended. In every multifloor building, an elevator is present, no matter how short or tall. Recall those times when the elevator door opens and you step inside to find that it was headed in the wrong direction? Has this ever made you wonder who or what is controlling it to do so? To give you a clue, there is a defined program running in a PLC that detects the different floors requesting the elevator and directing the elevators in their required direction. These programs are sets of ladder logic instructions that are loaded into the PLC controlling the lift. The controllers are usually not located in the elevator itself but at a specific location on the roof of the building or in a nearby control room. I once naively believed that summoning an elevator to my floor was performed on a first come, first serve basis but this is not the case, if the elevator is already in motion. Most elevators are programmed and controlled by PLCs to take the most optimized route through any pending button calls and make their directional decisions based on that.

SOURCE : https://www.gbctechtraining.com/blog/PLC-Applications-in-our-Everyday-Lives

In the Travel Industry, PLC has been used to monitor the safety control system and to operate lifts and escalators.

PRCs controllers have been in use in the glass industry for decades. They are used largely to control the material ratio as well as to process flat glasses. The technology has been advancing over the years and this has created an increased demand for the PLC control mode for use in the glass industry.

The production of glass is an elaborate and sophisticated process so the companies involved often use PLCs with the bus technology in its control mode.

Overall, the PLC is applied in both analogue data recording in the glass production, and in digital quality and position control.

In the paper industry, PLCs are used in various processes. These include controlling the machines that produce paper products at high speeds.

For instance, a PLC controls and monitors the production of book pages or newspapers in offset web printing.

Manufacturing cement involves mixing various raw materials in a kiln. The quality of these raw materials and their proportions significantly impact the quality of the final product. To ensure the use of the right quality and quantities of raw materials, the accuracy of data regarding such process variables is of the essence.

A distributed control system comprised of PLC in its user mode and a configuration software are used in the industry’s production and management processes. The PLC in particular, controls ball milling, coal kiln and shaft kiln.

Other examples of PLC programming applications that are in use in various industries today include water tank quenching systems in the aerospace sector, filling machine control system in the food industry, – industrial batch washing machine control and closed loop textile shrinkage systems.

Source : https://www.mobileautomation.com.au/plc-industrial-application/#:~:text=Other%20examples%20of%20PLC%20programming,closed%20loop%20textile%20shrinkage%20systems.

URL
- https://www.slideshare.net/jakahamedali/plc-programming-methods-and-applications
- http://jessicasiboro.blogspot.com/2017/10/industrial-electronics-with-plc.html
- https://www.daenotes.com/electronics/industrial-electronics/PLC-programable-logic-control

URL : https://www.agaraminfotech.com/blogs/2018/plc-integration-in-manufacturing-assembly-line

They were first developed in the automobile industry to provide flexible, ruggedized and easily programmable controllers to replace hard-wired relays, timers and sequencers. Since then they have been widely adopted as high-reliability automation controllers suitable for harsh environments. A PLC is an example of a “hard” real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result.

 

Example or application where PLC can be implemented:

 

Do you recall a time not too long ago when a person might be hit by an automatic door swinging open? Luckily today, there are better PLC controls with better built-in sensor on both sides of the door to prevent such occurrences. There are a many ways for an automatic door to function but in general they operate by way of a detector, for example a beam of light being broken,  causing the system to identify something in front of, or between, the doors.

 

When paying for your purchases at your neighborhood supermarket, the lowly conveyer belt moves your purchases into the reach of a friendly cashier.   Imagine the inconvenience, if a plc was not there helping control the belt, making the process of checking out simple and painless. Bigger conveyer belts can be found in airports where they transport people or put your luggage on carousel until you claim it. There are even giant conveyor belts that transfer construction materials. Conveyor belts are also used in most manufacturing plants due to their convenience and uniform motion.

 

Many people love exploring new heights and pushing themselves towards the thrill of a near death experience, on you guessed it, the PLC controlled roller coaster. Whether or not you scream at the top of your lungs is a different story.
Typically, the PLC  control in roller coasters is for bringing it upwards before the big drop. It is also used for safety measures so that the cars do not reverse in direction. Imagine travelling backwards on the huge dip; it wouldn’t be as thrilling as the gravitational force pulling down.
Almost everywhere you look today, PLCs are playing an important part controlling the technology that supports our hi-tech lifestyles. From traffic lights to roller coasters they provide us with robust and reliable control mechanisms that improve our lives. PLC technicians work to maintain and support these technologies, providing a critical service that keeps us safe and moving through our busy lives. 

 

Source

1. https://engineering.eckovation.com/plc-based-final-year-projects/

2. https://www.gbctechtraining.com/blog/PLC-Applications-in-our-Everyday-Lives

 Example or Application where PLC can be implemented:

PLCs are used in various applications in industries such as the steel industry, automobile industry, chemical industry and the energy sector. The scope of PLCs dramatically increases based on the development of all the various technologies where it is applied.

A distributed control system comprised of PLC in its user mode and a configuration software are used in the industry’s production and management processes. The PLC in particular, controls ball milling, coal kiln and shaft kiln. Other examples of PLC programming applications that are in use in various industries today include water tank quenching systems in the aerospace sector, filling machine control system in the food industry, – industrial batch washing machine control and closed loop textile shrinkage systems.

PLC is also used in the coal-fired boiler fan change-over system in hospitals, corrugation machine control system and silo feeding as well as injection moulding control systems in the plastic industry.

The programmable logic controllers at Mobile Automation includes a huge variety from various top industry manufacturers such as Allen-Bradley and Omron. All these can be put to various applications in key departments of your business to standardise the production process and increase your return on investment.

 

URL
https://www.allaboutcircuits.com/technical-articles/what-is-a-plc-introduction-to-programmable-logic-controllers/
https://www.mobileautomation.com.au/plc-industrial-application/#:~:text=Other%20examples%20of%20PLC%20programming,closed%20loop%20textile%20shrinkage%20systems.

 

 

Here are some examples of everyday mechanical systems that are controlled by PLCs:

 

It’s difficult to picture our modern world without traffic signals. Those three colored streetlights are used and understood by people all around the world. This simple but ingenious application of the PLC has a long history in major cities and small towns all around the world, since their first application traffic control in 1926 in London, England. These traffic lights, that we take for granted every day are monitored and controlled by PLC hardware and software, running dependably and without fuss 24/7/365 days a year

 

In any busy metropolis where car traffic is present, there are many gas stations accompanied by automatic or “touch-less” car wash stations. As you take a trip inside the touch-free carwash, you will find the water mixed with cleaning solutions, blasting the surface of the vehicle and spinning wipers for scrubbing. Every process is calculated and carefully controlled, from how many litres/gallons of soap is used, to the length of time those tall rotating wipers spin. These time and work saving services are completely automated by PLCs, with little human interaction other than a press of button at the entrance.

 

PLC that detects the different floors requesting the elevator and directing the elevators in their required direction. These programs are sets of ladder logic instructions that are loaded into the PLC controlling the lift. The controllers are usually not located in the elevator itself but at a specific location on the roof of the building or in a nearby control room. I once naively believed that summoning an elevator to my floor was performed on a first come, first serve basis but this is not the case, if the elevator is already in motion. Most elevators are programmed and controlled by PLCs to take the most optimized route through any pending button calls and make their directional decisions based on that.

PLC controls with better built-in sensor on both sides of the door to prevent such occurrences. There are a many ways for an automatic door to function but in general they operate by way of a detector, for example a beam of light being broken,  causing the system to identify something in front of, or between, the doors.

 https://www.gbctechtraining.com/blog/PLC-Applications-in-our-Everyday-Lives

 

 

PLC programming requires certain knowledge and skills. PLC programming is just a part of the entire task of automating a machine. A professional has to create an automation design and specify which components supply PLC together with the inputs and outputs it will control.

        If using a PLC in any applications, we just change the software component              for each application only. But, with other microcontroller system, we should   
        to change the hardware components with different applications.

PLC programming even withstands harsh environments and controls just like automatic machinery. Then, it also turns outputs on and off but this depends on the internal program and conditions. It is needed in the business world for who want to learn about this kind of programming.

PLCs share many features of the personal computer you have at home. They both have a power supply, a CPU (Central Processing Unit), inputs and outputs (I/O), memory, and operating software (although it’s a different operating software). The biggest differences are that a PLC can perform discrete and continuous functions that a PC cannot do, and a PLC is much better suited to rough industrial environments. A PLC can be thought of as a ‘ruggedized’ digital computer that manages the electromechanical processes of an industrial environment.

PLCs play a crucial role in the field of automation, using forming part of a larger SCADA system. A PLC can be programmed according to the operational requirement of the process. In the manufacturing industry, there will be a need for reprogramming due to the change in the nature of production. To overcome this difficulty, PLC-based control system were introduced. 

good example or application where PLC can be implemented :

Paper Industry

- As we know, paper mills are factories that produce many products at a time. such as paper, it requires thin and evenly cut pieces. Human labor cannot produce paper in such a short period of time. Machines that use plc will work to deliver a neat and accurate cut in a short amount of time. For example, at a time when the factory will produce half a million volumes of paper to be packaged, workers will use the PLC method to ensure that the paper is produced properly.

URL:
https://www.electrical4u.com/programmable-logic-controllers/

 

The PLC will then activate whatever output the program says to run. An output can be anything that does work such as a motor, solenoid, heater, or a light. In an automated process, that output will typically programmed as an input to the PLC and combined with other input devices or programming to keep the process running. With this programming, it can act like a chain reaction with one output device starting before the next is allowed to run. This is also called sequential starting. 

Automation has to have many aspects working together in order to function properly. An automated process will continue its cycle until it receives a stop signal. That can come from a physical input such as a stop button or sensor, or something programmed like a timer. Automation is an automatic process, typically controlled by computers and sensors. There is usually very little human intervention. Input devices, such as sensors and switches, will work with a controller or PLC to activate output devices like motors or other machinery. The PLC will advance as it was programmed. 

link: https://realpars.com/what-is-process-automation/

 is a means of monitoring and controlling a process. The PLC is a specialized computer that is used for the overall control and operation of processes.  It uses a programmable memory to store instructions and execute specific functions that include on/off control, timing, counting, sequencing, arithmetic and data handling.

It is designed to operate in an industrial environment and its original purpose was to replace hardwired relays.  With the development of modern electronics the PLC has increased in reliability and flexibility all at a lower cost and has become a workhorse in the oil and gas industry today.

In this course the participants will learn about PLC hardware and how each piece of the PLC contributes to its overall operation and reliability.  Discussions will cover the different numbering systems which form the basis of digital control logic as well as the various types of programming and options available in building a control program.  The course will close with coverage of how to properly install, maintain and troubleshoot the PLC.  Safety is included and will be stressed throughout this course.

With the advantages of economy and reliability, pipeline transportation has become the most important mode of oil and gas transportation in our country, which plays an important role in the development of national economy. However, the length (thousands of kilometers, hundreds of valve chamber), the transmission intensity, the complex terrain, and easily affected by climate change, which is a great challenge for oil and gas pipeline process operation, management and monitoring. 

The PLC control system in oil and gas pipeline is to monitor the parameters of oil and gas pipeline transportation by means of all kinds of automatic monitoring instruments and control equipment, to manage and to adjust field equipment. The purpose is to deliver the oil and gas products to the user in the most economical way and the fastest way under the safe condition. In addition, the automation system can also reduce the degree of labor, save costs and improve the level of the environment.

link : https://www.nexttraining.net/course/2351#:~:text=Programmable%20Logic%20Controller%20(PLC),monitoring%20and%20controlling%20a%20process.&text=With%20the%20development%20of%20modern,oil%20and%20gas%20industry%20today.

This is one of the important application of PLC in the bottle filling industry where we want our the bottles, which move on the conveyor belt, to be automatically detected in the proper position and fill the desired liquid. The machine will implement a control program that detects the position of a bottle via a limit switch then waits for 0.5 secs, and then fills the bottle until a photodetector detects the filled condition of the bottle. After the bottle is filled, the buzzer sounds and the control program will again wait for 0.7 secs. before moving to the next bottle.

https://automationforum.in/t/continuous-bottle-filling-system-using-plc/3937

PLC operation is very easy. The decision-making process is based on the "ladder logic" written by the user. To use the program properly, the PLC must communicate with a variety of monitored and controlled field devices. It then shows the actual state of the field device with whatever program it directs it to perform, and updates the output device accordingly. 
-The input switch is pressed. 
-Enter module "1" in the data input table. 
-The ladder logic program sees "1" and causes "1".
-The output data table generated output module energizes the relevant point. 

-Power output device.

Components of PLC

PLC have grown throughout the industry application industry as they provide them with the ability to create controllers: programming facilities, wiring facilities, installations, and transformations. All PLC have the same basic components. These components work together to find out the information in the PLC from the field, the information provided, and the information back to various fields. Without the main components, the PLC will fail to function properly. The PLC includes a variety of measurements, all other components such as: 

-Power supply 

-Module input 

-Output module 

-Processor (CPU) 

-Shelf or mounting rack 

-Programming unit (software).

Link 

 

In a simple word, PLC (Programmable Logic Controller) is one of the component that used and needed for industrial automation. These controller can automate a specific process, machine function, or even an entire production works. The PLC receives information from connected sensor/ input devices to process the data and then send out the output based on pre-programmed parameters. And all of these steps happen in one scan cycle and that’s how PLC works.

Components of PLC

PLC have grown throughout the industry application industry as they provide them  The PLC includes a variety of measurements, all other components such asPower supply, Module input, Output module, Processor (CPU), Shelf or mounting rack, Programming unit (software).

Wastewater treatment is the one of the application where the PLC is used for. Wastewater treatment is a process used to convert wastewater which is a water no longer suitable for most of the recent use into an infant that can be either retained to a water cycle with minimum environment. This process is consist of many unit operation such as inlet screening. PLC can be used to improve the waterwaste treatment with its own programming to control and measure the liquid level of the tank.

 

 https://www.youtube.com/watch?v=Rtp0fiUiRK4&t=213s

For example : the glass industry
PRCs controllers have been in use in the glass industry for decades. They are used largely to control the material ratio as well as to process flat glasses. The technology has been advancing over the years and this has created an increased demand for the PLC control mode for use in the glass industry.The production of glass is an elaborate and sophisticated process so the companies involved often use PLCs with the bus technology in its control mode. Overall, the PLC is applied in both analogue data recording in the glass production, and in digital quality and position control.
link
https://www.google.com/search?q=the+use+and+field+of+plc&rlz=1C1SQJL_zh-CNMY838MY838&oq=&aqs=chrome.0.69i59l4.1696599996j0j7&sourceid=chrome&ie=UTF-8

Programmable logic controller atau nama singkatannya PLC adalah digital computer diperkenal pada tahun 1960 an untuk mengawal mesin di kilang dan industri dengan melakukan automation. Sebelum adanya PLC ini sektor kilang menggunakan ribuan relay dan timer untuk mengawal turutan dan logic sebuah mesin. PLC akan disambungkan ke Komputer melalui Ethernet, RS232, RS485 atau RS422. Program PLC menggunakan Ladder Diagram untuk melakukan proses dan aritmatik.

Konsep yang digunakan oleh PLC adalah :- 

PROGRAMMABLE yang berkemampuan dalam hal memori untuk menyimpan program yang telah dibuat dengan mudah untuk diubah -ubah fungsinya dan kegunaan mengikut kesesuaian tugasan.

LOGIC yang memproses input secara arithmetic-logic unit (ALU) dengan melakukan operasi membandingkan , menjumlahkan ,menolak, membahagi ,AND,OR dan lain lain lagi.

CONTROLLER yang berfungsi untuk mengawal dan mengatur proses sehingga menghasilkan output yang dikehendaki . 

Antara contoh atau aplikasi yang baik dimana PLC boleh digunakan adalah 

1)     SISTEM KAWALAN LAMPU ISYARAT dimana Konsep system lampu isyarat adalah mudah dimana lampu isyarat menyala mengikut turutan dari lampu merah ke lampu hijau dan lampu oren dalam jangka masa yang telah ditetapkan. Sistem lampu isyarat masa kini menjadi lebih kompleks kerana pertambahan persimpangan, penggunaan sensor bagi mengesan kehadiran kenderaan dan kewujudan lampu isyarat yang lebih pintar.

 

2)     SISTEM PENCUCI KERETA AUTOMATIK dimana mesin diaktifkan pada permulaan litar, apabila sel beban mengesan berat yang serupa dengan kenderaan. Mesin ini mengaktifkan motor yang mengawal penghantar dan mula menghitung pewarna sabun, pencuci dan pengeringan.

Untuk sabun, pengawal logik yang boleh diprogramkan bertindak pada pam dos sabun. Setelah masa selesai, pam basuh diaktifkan. Pada masa yang sama, relay yang mengawal ketiga motor setiap sikat diaktifkan untuk menggosok kereta dengan sabun setelah selesai  pemasa ketiga (pengeringan) diaktifkan, kipas mula aktif. penghantar membawa kereta ke hujung laluan; apabila ia dikesan oleh suis had, keseluruhan proses ditutup. Butang hidup / mati manual telah dipasang untuk menghentikan atau menghidupkannya, bila diperlukan.

 
https://books.google.com.my/books?id=jdzs3ocXBhIC&pg=PA2&lpg=PA2&dq=plc+mesin+mencuci+kereta&source=bl&ots=EvRayg-66V&sig=ACfU3U3VkKpLDB3K7hQ3TE-cwSC4YtDewA&hl=en&sa=X&ved=2ahUKEwjl38bt9fTpAhW38XMBHacNASIQ6AEwDHoECAwQAQ#v=onepage&q=plc&f=false

   
 https://www.industrialshields.com/case-study-automatic-car-wash-with-arduino-plc-based

PLC programming is used in industrial applications.  They are often used to control equipment used in manufacturing.

Some of the industries that use PLC programming are:

D20182086557

Group:A
A programmable logic controller (PLC) is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. Figure 1 shows a graphical depiction of typical PLCs.

Advantages of PLCs
There are six major advantages of using PLCs over relay systems as follows: 

· Flexibility

· Ease of troubleshooting

· Space efficiency

· Low cost

· Testing

· Visual operation

Components of a PLC
All PLCs have the same basic components. These components work together to bring information into the PLC from the field, evaluate that information, and send information back out to various field. Without any of these major components, the PLC will fail to function properly.

The basic components include a power supply, central processing unit (CPU or processor), co-processor modules, input and output modules (I/O), and a peripheral device.

Link:

One good example or application where PLC can be implemented is which is also commonly used in civil applications such as in washing machines and for controlling traffic signals and elevators. They are used in many industries to monitor and control production processes and building systems.

As the next example is Paper industry.

Paper printing .In the paper industry, PLCs are used in various processes. These include controlling the machines that produce paper products at high speeds.For instance, a PLC controls and monitors the production of book pages or newspapers in offset web printing.

https://www.mobileautomation.com.au/plc-industrial-application/#:~:text=Other%20examples%20of%20PLC%20programming,closed%20loop%20textile%20shrinkage%20systems.

PLC operation is quiet easy as the decision-making process is solely based on the "ladder logic" written by the user. To use the program properly, the PLC must communicate with a variety of controlled and monitored field devices. It then shows the genuined state of the field device with whatever program it directs it to perform, and updates the output device accordingly. 
-The input switch is pressed. 
-Enter module "1" in the data input table. 
-The ladder logic program sees "1" and causes "1".
-The output data table generated output module energizes the relevant point. 

-Power output device.

PLC have been used  frequently in the industry application industry as they provide them with the ability to create controllers: programming facilities, wiring facilities, transformations and installations. All PLC have the similar basic components. These components cooperate to learn the information in the PLC from the information provided, the field, and the information back to various fields. Without the main components, the PLC cannot function properly as usual. 

The PLC includes a variety of measurements, all other components such as: 

-Power supply 

-Module input 

-Output module 

-Processor (CPU) 

-Shelf or mounting rack 

-Programming unit (software).

PLC in Glass Industry
PLC's controller have been in use in the glass industry for decades. They are used in largely to control the material ratio as well as to process flat glasses. The technology has been advancing over the years and this has created an increased demand for the PLC control mode for use in the glass industry.

The production of glass is an elaborate and sophisticated process so the companies involved often use PLC's with the bus technology in its control mode.

Link
https://www.mobileautomation.com.au/plc-industrial-application/#:~:text=Other%20examples%20of%20PLC%20programming,closed%20loop%20textile%20shrinkage%20systems.

Sistem PLC ialah satu sistem elektronik/ peranti operasi digital yang digunakan di dalam persekitaran industri, yang mana menggunakan ingatan yang boleh diatur cara untuk menyimpan arahan-arahan yang digunakan untuk melakkukan sesuatu fungsi seperti logik, jujukan, pemasa, pengiraan, dan arithmetik untuk mengawal sesuatu proses atau mesin berdasarkan input dan output yang disambung kepada modul sama ada digital atau analog. Dalam erti kata lainnya ia merupakan satu komputer digital yang direka khusus untuk kawalan untuk mengawal sesebuah alat atau mesin atau proses dan banyak digunakan didalam industri.

Terdapat banyak kegunaan sistem  PLC dalam industri ini antaranya adalah :

·         Industri kaca

·         Industri pembuatan kertas

·         Industri pembikinan simen dan banyak lagi

Antara contoh lain penggunaan sistem atau aplikasi PLC dalam industri ialah, elevator automatik atau escalator yang mana elevator yang secara automatik akan ON semasa ada orang yang akan menaikinya. Kemudian akan secara automatik akan OFF jika dalam tempoh waktu tertentu elevator ini tidak mengesan keberadaan orang yang akan menaikinya. 

Motor penggerak elevator ini memiliki keupayaan daya tegangan bolak-balik (Ac) dari PLN yang sangat penting dalam pelaksanaan kerja elevator, motor penggerak ini mempunyai kemampuan putaran antara 50 putaran per minit sehingga 210 putaran per minit. Dengan kapasiti tegangan motor yang disesuaikan dengan kapasiti beban. Motor penggerak ini dilengkapi dengan rem magnet ( magnetic brake ) yang berfungsi menahan motor ketika beban telah sampai pada lantai yang dituju, pergerakan cepat atau lambatnya elevator diatur oleh PLC (Programable Logic Control). Motor penggerak dalam menarik dan menurunkan elevator menggunakan tali baja ( rope ) yang melingkar pada puli mesin ( sheave ).

Sumber dari: 

1.       https://personalymda.wordpress.com/2011/06/15/programable-logic-controller/

2.       http://weeluntan.blogspot.com/2015/12/pengenalan-sistem-programmable-logic.html

3.       https://docplayer.info/45703813-Lift-elevator-escalator.html

4.       https://www.mobileautomation.com.au/plc-industrial-application/#:~:text=Other%20examples%20of%20PLC%20programming,closed%20loop%20textile%20shrinkage%20systems.

Secara ringkas, PLC (Programmable Logic Controller) adalah komputer dengan satu mikropemproses tetapi tidak mempunyai papan kekunci, monitor atau tetikus. PLC adalah sistem komputer kawalan industri yang secara berterusan memantau keadaan peranti input, memproses input ini menggunakan program khusus, outputnya digunakan untuk mengawal keadaan peranti output. Reka bentuk PLC sedemikian rupa sehingga dapat menahan operasi industri yang keras dan PLC dengan tepat dapat disebut sebagai jenis komputer khas untuk sistem kawalan industri. PLC dalam pembinaannya kukuh dan mempunyai ciri khas seperti kawalan yang boleh dipercayai, perkakasan yang mudah digunakan, kawalan berurutan, pembilang dan pemasa.

 

Berikut adalah beberapa contoh sistem mekanikal seharian yang dikendalikan oleh PLC:

 

1.       Automasi Industri menggunakan alat kawalan dan sistem seperti robotik dan komputer untuk mengautomasikan mesin industri dan operasi mereka yang menghilangkan keperluan untuk pengendali manusia. Automasi industri menjimatkan masa, menghilangkan kesalahan manusia, mengurangkan kos dan meningkatkan prestasi. Setelah kami memprogram PLC, mereka melakukan acara secara berurutan, dipicu oleh rangsangan yang disebut input. Input diterima melalui kelewatan masa atau kejadian yang dikira. Untuk mengikuti tuntutan standard industri yang semakin meningkat, PLC dirancang untuk menahan getaran, panas, kelembapan, suhu dan kebisingan yang melampau.

 

PLC sangat berguna dalam pelbagai industri seperti industri automobil, industri keluli, industri kimia, sektor tenaga dan sebagainya. Berdasarkan teknologi yang diikuti dalam industri, penerapan PLC bervariasi. Mari kita bincangkan beberapa industri di mana PLC membantu dalam automasi dan kawalan.

 

2.       Industri Kertas

 

Dalam industri kertas, PLC digunakan dalam pelbagai aplikasi termasuk kawalan dan pemantauan mesin. Contohnya, PLC mengawal dan mengautomasikan kelajuan mesin yang mencetak buku atau mengimbangi halaman web.

3.       Industri pelancongan

Dalam industri pelancongan, seperti di lapangan terbang, PLC digunakan untuk mengendalikan lif dan memantau sistem kawalan keselamatan.

 

4.       Industri Kaca

PLC telah digunakan dalam industri kaca selama beberapa dekad untuk mengawal nisbah bahan dan untuk memproses pengeluaran kepingan kaca besar. PLC digunakan dalam mod analog dan digital dalam industri kaca. Mod analog digunakan untuk rakaman data dan mod digital untuk kedudukan dan kawalan kualiti digital.

 

5.       Industri Pembuatan Simen

Bahagian penting dalam pembuatan simen berkualiti melibatkan pencampuran bahan mentah yang betul dalam perkadaran yang betul. Produk akhir sangat bergantung kepada proses pencampuran dan pemprosesan ini. Sistem kawalan yang diedarkan menggunakan PLC mengawal penggilingan bola, tanur poros dan tanur arang batu. PLC memastikan ketepatan data untuk mengukur kuantiti dan kualiti bahan mentah yang betul dalam pembuatan simen.

 

 

 

 

 

 

Link : 

1. https://www.gbctechtraining.com/blog/PLC-Applications-in-our-Everyday-Lives

2. https://study.com/academy/lesson/programmable-logic-controllers-plc-in-industrial-networks-definition-applications-examples.html