01 Overview of Control Systems - Final Script PDF

Client: EMC Course Introduction to PLCs Module #: 01 Module: Overview of Control Systems Duration: 30 minutes (estimated based on reading level and speaking time) Script Date: October 11, 2024 Script Version: Final Draft Link to Lesson: https:/...

Client: EMC Course Introduction to PLCs Module #: 01 Module: Overview of Control Systems Duration: 30 minutes (estimated based on reading level and speaking time) Script Date: October 11, 2024 Script Version: Final Draft Link to Lesson: https://360.articulate.com/review/content/74fdd5dc-771a-4fa3-82ee-c92cba46918b/review Cover Duration: 30-minutes You'll discover the main types of manufacturing processes and the control systems used in them. You will also be introduced to some of the background of PLC development, the advantages of a PLC, and begin to look at what they do. Click on the Start button above when you are ready to begin. If you need help with this content or would like more information, contact us at 866-323-4362 or [email protected]. [START] 01_Overview of Control Systems - Final Script 1 Introduction What You’ll Learn In the next 30-minutes, we're going to cover the main types of manufacturing processes and the control systems used in them. You will also be introduced to some of the background of PLC development, the advantages of a PLC, and begin to look at what they do. Scroll down to learn more. About This Module This module can be viewed on any device. Some content will be best viewed landscape when on a phone or tablet, like the interaction below. Click or tap on the icons to learn more about how this module operates. When done, scroll down to continue. (note) If you need help with this content or would like more information, contact us at 866-323-4362 or [email protected]. Ready to begin the first lesson? [LET’s GO!] 01_Overview of Control Systems – Final Script 2 Control Systems and PLCs What is a Control System? Manufacturing requires controlling temperature, movement, flow, light or some other physical property to create a changed product. A Control System is the combination of the devices that achieve the control of these physical properties. Let’s take a closer look. A Control System can be as simple as the devices your toaster uses to control toasting your bread. The brain of industrial control systems are Programmable Logic Controllers (PLCs). What is a PLC? A PLC is a purpose-built industrial computer that has electrical signaling hardware to interact with real world devices. They have their own programing languages developed to create rapid development and modification of logic that controls automated equipment. How a PLC is different from a computer? While Programmable Logic Controllers (PLCs) and computers have many similarities, the primary difference is that PLCs are specifically designed for automating industrial processes. Look at the table below to discover how PLCs compare to computers. What is being compared? PLCs Computers Designed for control automation in General-purpose devices used for a wide FUNCTION industrial settings, managing processes range of tasks: Data processing, and machinery. communication, and entertainment. Real-time operating systems designed Flexibility to support additional OPERATING SYSTEMS for deterministic and predictable programs, with variable times to execution. complete multiple tasks. Designed specifically for running custom Application programming requires APPLICATION PROGRAMMING developed applications in a few PLC additional software available in a wide specific languages. variety of languages. Use industrial networks that prioritize Use general networks that prioritize NETWORKING timely error free connections. data speed and volume. There are very few devices that allow INPUT AND OUTPUT CONNECTIONS Wide variety of modular interfaces to computers to interact directly with the WITH REAL WORLD DEVICES directly gather and send stable signals. real world. DATA STORAGE Minimal data storage compared to Often have 1000’s of times the storage 01_Overview of Control Systems – Final Script 3  computers, typically only MBs capacity. GB (Gigabytes) or TB (Megabytes). (Terabytes). Can operate in extreme temperatures Designed to operate within a moderate OPERATING CONDITIONS and are less susceptible to electrical temperature range and are quite interference. susceptible to electrical interference. Have no moving parts like fans and hard Are consumer products that can be RELIABILITY drives. They can operate reliably for expected to be obsolete or worn out in decades. only a few years. Up Next Before we explore how a Programmable Logic Controller works, let’s first look at different types of manufacturing processes and the types of control systems used. [CONTINUE] 01_Overview of Control Systems – Final Script 4 Types of manufacturing processes Two Types of Manufacturing There are two types of manufacturing: discrete and process manufacturing. It's important to first understand different types of manufacturing processes as they require different types of control systems. Let’s take a look. (video) Thumbnail: Two Types of Manufacturing Process Caption: Watch this video to see two types of manufacturing process in action. (01:46) Narration: Discrete Manufacturing is a manufacturing process where individual parts or components can be easily identified, and a start and end process is easily visible. Machining or assembly of products like pens, cars, or toys are examples of discrete manufacturing. Discrete manufacturing uses processes like cutting, pressing, welding, and many more. Process Manufacturing is a continuous manufacturing process where an individual product is not easily identified. Some processes occur entirely inside tanks, pipes and equipment making it difficult to see the start or end of the process and to see what’s happening at stages during it. The beginning stages of oil refining, paper, chemical production, pharmaceuticals, beverages, processed food and cosmetics are examples of process manufacturing. While some process manufacturing operates continuously, often the product is made in large batches. Like baking a cake, process manufacturing follows a recipe to create the product. Process manufacturing utilizes processes that are more variable, like controlling the flow of liquids, maintaining a specific temperature, or mixing specific amounts of raw materials. Most process manufacturing will end with a form of discrete manufacturing as the product is packaged. In most facilities you can expect to see both discrete and process manufacturing. Up Next Different types of manufacturing processes require different types of control systems. In the past different types of controllers were required but today's PLCs co-ordinate all these different processes. Let’s find out how. [CONTINUE] 01_Overview of Control Systems – Final Script 5 Discrete Manufacturing Control Systems What Do Discrete Manufacturing Controls Do? Discrete Manufacturing Controls primarily control devices that are either turned on or off in a repeating sequence. Let's take a closer look. Sequential Control Discrete manufacturing processes that are dealing with individual components primarily use this type of sequential control. In the past this type of sequential logic was controlled without the use of any electronics, but today PLCs are used to control all aspects of these systems. While PLCs are the brains of a control system, it’s made up of many components all working together. Let’s explore one such system. Control System Example This is the control system that operates the filling machine. It has an automatic lid dispenser, can seamer and rinse and dry station. Each has its own sequence of operation that’s controlled by a PLC. As you can see, even a a tiny PLC can control a lot. Select each marker to learn about the elements in this control system. (interactive graphic that shows operator interface connect to a PLCS, filling process, conveyor, valves for pneumatic cylinders, automatic lid dispenser, DC power supply, power supply for precision motors, PLC that controls entire machine operation, can seaming process, can rinser and dryer, seaming motors) (video) Thumbnail: Discrete Manufacturing Caption: Watch this video to see Discrete Manufacturing Controls in action. (00:41) Narration: Here is a beverage filling machine using pneumatic valves that are controlling the cylinders which is causing the motions. You can see that there is a repeating sequence operating the valves. Each step in a sequence like this is event controlled; meaning each step in the process is triggered by a specific event. 01_Overview of Control Systems – Final Script 6 In the beverage filling example when an event such as the fill head being inserted into the cans occurs, the fill valves are triggered to open to fill the cans. The next event is when the cans are filled, triggering the valves to close and the fill head to raise out of the cans. Up Next You can see how a PLC controls individual parts in the manufacturing process. In Process Manufacturing, devices can operate within a range rather than just on and off. Let’s take a closer look at this. [CONTINUE] 01_Overview of Control Systems – Final Script 7 Process Control Systems Variable Conditions In Process Manufacturing, both the sensors and process control devices use values that can vary; these are referred to as variable conditions. Let’s find out more. Process Control Systems assess and respond to variable conditions such as the amount of liquid in a tank or the quantities of materials being mixed. This requires sensors to monitor various values, such as temperature, flow rate, pressure, moisture, weight, volume, and pH. (video) Thumbnail: Variable Process Controls Caption: Watch this video to learn more about Variable Process Controls. (01:11) Narration: Items in the manufacturing process are often controlled in a variable manner. For instance, a valve may be opened to a specific percentage to maintain the level in a tank, a pump may be sped up to increase flow rate, or the amount of electrical energy sent to a heater may be increased or maintained to achieve a desired temperature. PLCs control processes like these using process control logic, which can be written as "if value A decreases below the setpoint, then increase value X proportionally to the deviation from the setpoint; if value A increases above the setpoint, then decrease X proportionally to the deviation from the setpoint." Beyond dealing with just the percentage of deviation from a setpoint, the level of precision of this type of control can be increased by adding Integral control which means duration of change, and Derivative control which is the rate of change. This is called PID control, which stands for percentage, integral, and derivative. Did you know? Cruise control is an example of PID Process Control. When your car starts to climb a hill, it slows down below the 80 kph setpoint, the control system responds by increasing the amount of fuel to maintain the car at 80 kph. When descending the hill gravity will make the car go faster, and the fuel will be reduced to try to maintain the 80 kph setpoint. Process Manufacturing also uses sequential logic but in a slightly different manner than Discrete Manufacturing. (video) Thumbnail: Sequential Logic in Action 01_Overview of Control Systems – Final Script 8 Caption: Watch this short video to see Sequential Logic in action. (01:23) Narration: Sequential logic is commonly used in process controls. In this example, we need to make salt brine for canning vegetables. First, the mixing tank needs to be filled with 1000 L of water, and then heated up and maintained at 98.5 degrees Celsius with PID control. When the temperature has reached the setpoint, the next step is to mix in 100 kg of salt. The salt is pumped in at a continuous rate of 100 kg per minute. After 1 minute the 100 kg of salt has been mixed in and the water is now 10% salt brine. The next step in the sequence is to open a discharge valve to the vegetable canner at a rate of 100 L/per minute. Now that some of the brine is being removed, more water and salt will have to be added to maintain the 10% salt brine. The water fill valve adjusts to add 100 L/minute of water and the salt flow reduces to 10 kg/minute of salt. With cold water and salt being added, the temperature control PID will now increase the heat to maintain the proper temperature. At this point the sequence is complete, and the process can now continuously output enough hot salt brine for 200 cans of vegetables every minute. Up Next Supervisory Control And Data Acquisition (SCADA) provides real-time control and oversight of manufacturing processes. Let’s take a closer look at this. [CONTINUE] 01_Overview of Control Systems – Final Script 9 Supervisory Control and Data Acquisition What is SCADA? SCADA, or Supervisory Control and Data Acquisition, is a critical system used in manufacturing processes to monitor, control, and automate various industrial operations. Let’s learn more. (flash cards) Supervisory Control This involves monitoring and controlling multiple PLCs that control equipment. It allows for co-ordination of the activities of multiple PLC’s that control equipment. Data Acquisition This involves continuously reading information from the PLC’s and sensors. This data is displayed on the SCADA screens. Many of these data values are then transferred to a database on the facilities computer network. (video) Thumbnail: How Supervisory Control Works Caption: Watch this short video to see how supervisory control works. (00:45) Narration: In the previous example of making a salt brine for canning food, if the temperature dropped too low or there was a shortage of salt, the canning process would need to stop. Similarly, if the food product ran out or there were problems with the canning or cooking equipment, the salt brine system would need to stop adding water and salt. In some cases, an operator may be able to override these conditions. For instance, if they only needed 500 L of brine to finish canning the food, an operator could override the system to empty the tank without adding any more water. These values are monitored and controlled and can be viewed at multiple locations. This data is often stored for comparison or compliance records. Controlling and Collecting Data SCADA systems, originally developed to perform tasks beyond the capability of early PLCs, range from expansive central command centers monitoring vast facilities across multiple screens (as shown in the image below) to compact single- screen setups situated close to the processes they manage, controlling and gathering data from various equipment. Today, both PLCs and computers are used together as parts of a SCADA system, taking advantage of the strengths of both devices. Expand each of the items below to learn more. (accordion) 01_Overview of Control Systems – Final Script 10 PLC Using a PLC for the supervisory control function of a SCADA system leverages the consistent real-time operation and communications of a PLC. The SCADA PLC can then perform automated supervisory control between pieces of equipment. For example: In the video above, the overrides performed by an operator could have PLC code to allow this to be performed automatically, keeping multiple pieces of equipment operating together continuously. Computer Computers can better store and process large amounts of data and can perform the data acquisition SCADA function while also hosting the monitoring screens and securely connecting to the computer network and the internet. In our Internet connected mobile device world, specialized SCADA systems have emerged. These systems connect and gather information from Internet of Things (IOT) devices, the Industrial Internet of Things (IIOT, I2OT or I2OT) devices, as well as PLCs. These systems allow for secure connections between manufacturing equipment and the Internet. Here’s a Question for You. (minor text change to answers) Is it necessary to use multiple PLCs to control all the activities that occur in an industrial production line? Yes No Feedback – It is possible to use a single PLC to control all the activities in an industrial production line. Many PLCs now communicate and send control data directly to other PLCs. They can also send collected data to a database stored on the facility's computer network. In some cases, a single PLC may perform discrete, process, and supervisory control. Up next… Let's see a PLC in Action! [CONTINUE] 01_Overview of Control Systems – Final Script 11 Let's see a PLC in action How a PLC Operates Watch the video below to learn how a PLC operates automated equipment in manufacturing. (video) Thumbnail: How Supervisory Control Works Caption: This video explains how PLCs operate. (01:16) Narration: PLCs have inputs that receive electrical signals from sensors, allowing them to understand the physical world. They also have outputs that send signals to control devices like motors and valves, enabling direct control of real-world machines. Here we have the beverage filling machine we saw earlier entry showing the stage where cans with lids are pushed into the can seaming operation. In this application there are two sensors that we can see on the equipment and in the diagram. The sensors detect when a can and lid are present. There is a pneumatic cylinder that pushes the cans into the can seamer. The PLC is wired to the valves solenoids that control the compressed air to move the cylinder. Let’s watch it operate. In order for the cylinder to push a can forward, the sensors must both be detecting that a can and a lid are present. You can see the inputs on the diagram light up at the same time as the sensors detect. As well, the two outputs to the valve turn on and off as the conditions in the program are met for the next step in the sequence. If something goes wrong, these types of indicators on devices can help to troubleshoot where a problem might be. Here are the Advantages of PLCs Expand each of the items below to learn more. (accordion) Reliability - PLC hardware is designed to operate reliably for decades in hot, electrically noisy environments. Flexibility - Program changes can be made quickly and easily. Advanced functions - PLCs can provide a wide variety of control tasks, from single or repetitive action to complex data manipulation. Communication - PLCs can communicate with operator interfaces, other PLCs or computers. Speed - Quick response capability. Diagnostics - The troubleshooting tools in the PLC software make it easy for the user to trace and correct software and hardware problems. Ease of duplication - Once a program has been written and tested, it can be easily transferred and downloaded to other PLCs. 01_Overview of Control Systems – Final Script 12 Up Next Let’s wrap up with a quick summary of control systems in manufacturing. [CONTINUE] 01_Overview of Control Systems – Final Script 13 The Last Step Summary and Completion Control Systems control and regulate physical property like motion, temperature, flow, and more. In manufacturing, Programmable Logic Controllers (PLCs) are the brains of control systems. Key Takeaways - Discrete Manufacturing - This is a type of manufacturing that uses sequential logic to control on-off devices and you can identify individual parts. - Process Manufacturing - This type of manufacturing uses individual parts that are not typically visible. Process Control precisely operates devices that can vary across a range of output levels. - Discrete and Process Manufacturing - These two types of manufacturing can be found in the same factory, and even within one piece of equipment. - Supervisory Control - Oversees and connects numerous pieces of equipment. A system that also collects data from the equipment to store in the computer network is called SCADA (Supervisory Control And Data Acquisition). - Programmable Logic Controllers (PLCs) - Used to automate industrial processes and can directly control devices in the real world. You’re Almost Done! Click the image below to complete this content. If you are on a mobile device, a play button may appear first. Click the play button then click the image. Once done, a sound will be heard and a completion message will appear. [CLICK TO COMPLETE LESSON] Great work! Click the Exit button in the upper right to close this window, or use the Menu in the upper left to access resources (if available) or review content. 01_Overview of Control Systems – Final Script 14 Resources Downloads and Links If you need help or would like more information, contact us at 866-323-4362 or [email protected]. - PLC Terminology (PDF) 01_Overview of Control Systems – Final Script 15