Read any report on the future of plant operations and manufacturing, and there is only one consensus: automation will disrupt virtually every area and process, including equipment communications, maintenance and repair, and production.
To date, the only area of manufacturing that seems unaffected by the automation takeover is programmable logic controllers, or PLCs. there's a reason why the global market for PLCs is at $16 billion per year and growing at 9.2% per year. Their robust design, low cost and simplicity in the face of complex integration have made them an essential part of manufacturing.
Without PLCs, many organizations would not be able to support the implementation of new control technologies. For now, PLCs remain an integral part of the digital transformation promised by Industry 4.0.
What is a PLC designed to do?
PLC stands for "Programmable Logic Controller" and is both a combination of units and a theoretical model for controlling input and output modules.PLC must include four basic components to be a complete system:
- CPU Module: This is the central processor and the memory required to store information and perform tasks. All data calculations and processing is done by receiving inputs and generating outputs.
- Power Supply: All the modules of a PLC depend on the power supply.PLCs are designed to receive AC power and convert it to DC power.
- Programming Devices: PLCs require programming software that introduces control logic into the system. The user can then create, transfer and make changes temporarily within the PLC software.
- Input/Output Modules: These units are an important part of the PLC system. Input and output modules collect data from sensors and actuators, feed it into the PLC system, and then generate readable information. These modules can be digital or analog.
The fact that the unit or system is programmable is a major improvement over the previous handling of task control. This is also a source of competitive advantage for PLCs: technicians do not have to change hardwiring when switching between tasks or applications. Instead, they can simply reprogram the device.
A PLC consists of a processor that performs control operations based on data supplied by input and output modules. The control logic that manages the PLC system is first developed and then transferred to the PLC system.
The easiest way to visualize a PLC is to imagine a computer with a microprocessor but without a keyboard, mouse, or monitor. Its wide range of industrial uses often means that this physically robust system can withstand very harsh environments.
Functional features of a PLC can include timers and counters, measuring devices, and sensors for parameters such as vibration, pressure, temperature, and flow. Although some industries have unique tasks and applications, PLCs typically perform the following functions:
- Relay switching
- Counting, calculation and comparison of analog values
- Modification of the control logic in the shortest possible time
- Fast response to changes in process parameters (response can be programmed)
- Monitoring and control over time to increase overall control system reliability (manual intervention required)
- Increasingly simple and effective troubleshooting over time
- Seamless integration with HMI (Human Machine Interface) computers
When built correctly, companies can utilize PLCs and use them in a wide range of applications across multiple industries. What you may not realize is that we have come to rely on PLCs for the most mundane, everyday technologies to function properly. Bakeries, washing machines, elevators and even traffic signals are among the many civilian applications that require PLC control and data collection to regulate tasks.
Why do manufacturing companies use PLCs?
In 2019 (and beyond), PLCs will continue to shine due to their inherent simplicity and flexibility. They're powerful enough to adapt to a wide range of environments and tasks, yet simple enough that even technicians with no programming or scripting knowledge can master them quickly.
Certain specific features of PLCs make them the first choice for industries that rely on these systems. Oil and gas, water utilities, food and beverage manufacturing, and public works use are just a few examples of industries that rely on the opportunities offered by PLCs.
1) PLCs are easy to program
When someone touts the flexibility of PLC systems as a benefit, they are talking about how these systems can be programmed by individuals with the sloppiest level of knowledge.
This means that technicians can use them just as easily as consumers. You can also expand a PLC system by programming it to follow a set of instructions if certain conditions are true.
With a wide range of uses across industries, each company's employees will have their own skill sets. When using PLCs, the simplicity of programming control logic into your system means you don't need someone versed in the nuances of computer language to rewrite a program when a task or application changes.
2) PLCs can provide a unified programming environment
PLCs are the preferred method of controlling, measuring and performing tasks in complex manufacturing and industrial applications because they work well with other systems.PLCs work well with PCs, PACs (programmable automation controllers), motion control devices and HMIs.
However, to be effective, a unified environment needs to be well planned and should not be too difficult for the user to operate. However, PLCs located in larger programming environments allow users with a basic level of knowledge to access multiple functions that can communicate with each other, provide data to each other, and perform complex tasks.
3) PLC collects reliable data
The number of inputs you set on the PLC system is determined by the user. This means that there is no limit to the number of data sources and the amount of data that can flow in. Measuring devices, sensors and motion controls can acquire multiple parameters, so it is up to the user to decide how this data is collected and how the outputs are displayed.
4) PLCs can be used for predictive maintenance
Because today's PLCs are equipped with more memory and processing power, they can be programmed to perform complex and demanding tasks. One of these tasks is predictive maintenance. The power of predictive maintenance, especially at the start of Industry 4.0, cannot be overemphasized.
In the connected factory, which is one of the features of the fourth industrial revolution, one machine can be connected and responsible for the operation of several other processes. As a result, predictive maintenance can significantly increase efficiency and reduce the frequency of downtime and catastrophic events.
Predictive maintenance starts with preventive maintenance. If a specific piece of equipment reaches a predetermined threshold, a sensor turns off, telling technicians that the equipment needs to be serviced or replaced. Enough of these reports are then collected as data points themselves to communicate to the system what factors predict wear and tear or impending problems. the PLC will interact with the SCADA to display maintenance schedules or allow for flexibility in configuring new maintenance rules.
Conclusion
PLCs are now more than ever proving their worth as manufacturing and plant-based industrial companies embrace the digital transformation required for their niche markets. Their fundamental ease of use and simplicity make them a flexible and familiar solution in the face of increasing complexity.
Professionals prefer PLC systems when using other IoT applications or when working with control systems such as SCADA. As a logic control system, PLCs are well suited to Industry 4.0 trends that require data prediction, error state prediction, correlation discovery between two or more independent PLC data streams, and system optimization.
The critical position and role of the PLC also requires it to remain fully functional at all times. Manufacturers and plant companies can adopt best practices to ensure that these core components are always running smoothly.