Key Takeaways
- A PLC is an industrial computer that reads inputs from sensors and switches, executes control logic and drives outputs such as motors, valves and relays.
- Arduino PLCs bring PLC functionality to the open-source Arduino platform, removing the cost of proprietary software licensing.
- Key benefits include lower costs, community support, flexibility, code transparency, rapid prototyping and less vendor lock-in.
- L-com’s M-DUINO PLCs offer up to 58 analog and digital inputs and outputs and communicate via Ethernet, RS-485 or RS-232.
- Arduino PLCs suit process control, plant automation, agriculture, building automation and educational use.
Programmable logic controllers, or PLCs, are a key component in the automation hierarchy, bridging the gap between sensors and actuators to enable reliable control of industrial processes – but what is an Arduino PLC? Arduino is a popular open-source electronics platform that is often used for prototyping and DIY projects, so using an Arduino PLC with open-source programming allows you to control your industrial automation while saving you money.
Most programmable logic controllers from traditional automation companies require proprietary software licensing for programming. However, open-source programming is disrupting the industry by bringing low-cost solutions to automation controls. Always on the cutting edge, L-com recently began offering a line of Arduino-based PLCs.
Below we provide background on the main functions of PLCs and explain the general benefits of Arduino-based models and a few features of our new line.
Functions of Programmable Logic Controllers (PLCs)
A PLC is a specialized industrial computer used in industrial automation and control systems to automate processes and machinery. PLCs find applications in a wide range of industries, including manufacturing, chemical processing, power generation, water treatment, and more. They play a crucial role in controlling and monitoring industrial processes by executing logic-based tasks. Here are some of their key characteristics and functions in industrial automation:
- Logic Control: PLCs are designed to execute logical operations based on the input received from sensors and other devices. They implement control algorithms to make decisions and control the operation of machines and processes.
- Input/Output Handling: PLCs interface with a variety of input devices, such as sensors and switches, to gather information about the state of the system. They also connect to output devices − such as motors, valves, and relays − to control the physical processes. Learn more about common input devices in our article on IoT pressure, differential pressure and proximity sensors.
- Programmability: PLCs are programmable devices, allowing engineers and programmers to create custom control programs. These programs are typically developed using ladder logic, a graphical programming language that resembles electrical relay logic diagrams.
- Real-Time Operation: PLCs operate in real-time, meaning they respond to input signals and execute control logic within a specified time frame. This ensures timely and accurate control of industrial processes.
- Modularity and Expandability: PLC systems are often modular, allowing users to expand and customize them based on the complexity of the automation task. Additional input/output modules, communication modules, and other accessories can be added as needed.
- Robustness and Reliability: PLCs are designed to withstand harsh industrial environments, including temperature variations, humidity, and electrical noise. They are built for high reliability and longevity in demanding applications.
- Communication Capabilities: PLCs often support communication protocols that enable them to exchange data with other control devices, supervisory systems, and enterprise-level software. This facilitates integration within larger automation systems. See how Industrial Ethernet connects PLCs, sensors and HMIs on the plant floor.
- Monitoring and Diagnostics: PLCs provide features for monitoring the status of inputs and outputs, as well as diagnostic tools to identify issues in the system. This helps in troubleshooting and maintenance.
Traditional PLCs deliver all of these functions, but usually through proprietary hardware and licensed software. Arduino-based PLCs offer the same core capabilities with an open-source approach, and that brings some distinct advantages.
Benefits of the Arduino PLC
Using an Arduino-based programmable logic controller with open-source programming offers several advantages over proprietary software licensing:
- Cost-Effectiveness: Open-source software is typically free to use, allowing users to develop, modify, and distribute programs without incurring licensing costs. This can be particularly beneficial for small-scale projects or applications with budget constraints.
- Community Support and Collaboration: Open-source projects often have active and engaged communities. Users can collaborate, share knowledge, and help develop libraries, tools, and documentation. This community support can be valuable for troubleshooting.
- Flexibility and Customization: Open-source programming gives users the flexibility to customize the software according to their specific needs. This is especially useful in industrial automation where customization may be required to address unique requirements.
- Transparency: Open-source software allows users to inspect the source code, providing transparency into how the system works. This transparency can enhance trust, enable better understanding of the system behavior, and facilitate troubleshooting.
- Rapid Prototyping and Development: Open-source programming environments often have a quicker development cycle. Users can rapidly prototype and iterate on their programs, accelerating development and reducing time-to-market for automation projects.
- Platform Independence: Open-source programming environments are often cross-platform, meaning they can run on different operating systems. This gives users the flexibility to choose the hardware and operating system that best suits their needs.
- Long-Term Availability: Open-source projects are less susceptible to issues related to vendor lock-in. Even if the original developers discontinue the project, the community may continue its development and maintenance, ensuring long-term availability and support.
- Integration with Other Open-Source Tools: Arduino-based PLCs with open-source programming can be integrated with other open-source tools and platforms, enhancing interoperability and expanding the range of available features.
As with any networked controller, Arduino PLCs should be deployed with security in mind; our guide to the top cybersecurity risks in industrial automation covers what to watch for.
So what do these benefits look like in practice? Here’s what L-com’s Arduino-based line offers.
L-com’s New Arduino-Based PLCs and Power Supplies
L-com offers a new line of M-DUINO PLCs that use open-source Arduino programming. They feature up to 58 analog and digital inputs and outputs. They accept I/O or sensors and power as inputs and deliver outputs to actuators and human machine interfaces (HMIs) based on computer programs (modified C++ language). In addition, we offer three new power supplies that convert AC to DC to run PLCs and other devices.
Key Features:
- Cost-Effective – Program PLCs using free open-source software
- User-Friendly – Easy to install and operate via Ethernet, long-distance multi-point RS-485, or short-distance point-to-point RS-232
- Expandable – PLCs feature up to 58 ins/outs to accommodate future expansion
- Versatile – Great for process control, plant automation, traffic systems, food and beverage, agriculture, and automated offices and homes
- Power Options – Our new power supplies include 12 VDC and 24 VDC options with power output ranging from 30 watts to 240 watts
- Protected Power – DIN-rail-mountable power supplies have overvoltage and overcurrent protection
L-com’s newly released Arduino PLC product line, as well as our line of compatible power supplies, are in stock now and available for immediate shipment. All orders on in-stock products placed before 6 p.m. CST weekdays will ship the same day.
Still have questions? Here are the ones we hear most often.
FAQs About Arduino PLCs
Q1: What is an Arduino PLC?
A: An Arduino PLC is an industrial controller built on Arduino-compatible hardware and programmed with open-source Arduino software. It combines the low cost and flexibility of Arduino with industrial features such as protected inputs and outputs, industrial power ranges and communication ports like Ethernet, RS-485 and RS-232.
Q2: What is the difference between an Arduino and a PLC?
A: A standard Arduino is a general-purpose microcontroller board designed for prototyping and hobby projects. A PLC is a ruggedized controller built for reliable, real-time control in harsh industrial environments. An Arduino PLC combines the two, pairing open-source programming with industrial-grade hardware.
Q3: What programming language does an Arduino PLC use?
A: Arduino PLCs are programmed in the Arduino language, which is based on C/C++, typically using the free Arduino IDE. Traditional PLCs, by contrast, are usually programmed with ladder logic in proprietary software.
Q4: Can Arduino PLCs be used in industrial applications?
A: Yes. Industrial-grade Arduino PLCs are designed for applications such as process control, plant automation and agriculture. Standard Arduino boards, however, are not built to withstand the electrical noise, temperature changes and vibration found in industrial settings.
Summary
Using an Arduino PLC offers the benefits of affordability and flexibility, making it an ideal choice for automation networks and educational purposes. It allows for easy customization and integration with various sensors and actuators, providing a versatile platform for prototyping and development. Additionally, the open-source nature of Arduino ensures extensive community support and resources for troubleshooting and innovation.