Comparison of PLC and Arduino

What is a PLC?
A Programmable Logic Controller (PLC) is an industrial computer with different inputs and outputs that uses custom programming to control and monitor industrial equipment. PLCs are used in the water and wastewater treatment, manufacturing, and food and beverage industries.

PLC Components

• Central Processing Unit (CPU): The brains of the PLC, the CPU executes the control program. It's an electrical gadget with memory, I/O ports, and a processor.
• Input/output (I/O) modules: I/O modules are used to connect the PLC to the process. These modules could be analog or digital. Measurements of physical quantities, such as the level of a liquid, are converted into electrical impulses by analog modules. Digital modules monitor the condition of a switch or sensor and convert it to a binary signal.
• Memory: The control software and other data, including the input and output statuses, are stored in the memory. The memory could be volatile (which loses its contents when the power is turned off) or non-volatile (which retains its contents even when the power is turned off), depending on the sort.
• Power supply: The PLC controller and the I/O modules are both powered by this source. It converts AC power from the mains into DC power that the PLC can use.
• Programming tool: The programming tool is used to program the PLC controller. It could be a portable programmer, a laptop, or a programming terminal.
• HMI (human-machine interface): Through the HMI, one can communicate with the PLC controller. It might be a touchscreen display, a keypad, or a light bar.
• Communication modules: These modules are used to connect the PLC controller to other devices, such as networks and computers. This enables the PLC controller to be remotely programmed, monitored, and controlled.

What is an Arduino?
An Arduino is an open-source platform that helps circuit designers create electronic creations. It consists of both software and hardware. The Arduino hardware is composed of programmable circuit boards called microcontrollers. Developers use the Arduino software, an IDE (integrated development environment), to write and upload code to the microcontroller.

Arduino Components

• Microcontroller: The brains of an Arduino board are found in its microcontroller. This device runs the Arduino software on a small computer.
• I/O (input/output) pins: The Arduino board can be connected to external devices via these pins. They can control output devices like motors and LEDs and read sensor data.
• Power source: The power source provides electricity to the Arduino board. Either a USB cord or an external power supply will work.
• Language for programming: The programming language used in Arduino is a streamlined variant of C/C++. It is easy to use and learn, making it a good choice for beginners.
• Development environment: The Arduino development environment is a software tool that is used to write and upload Arduino applications. Linux, macOS, and Windows can all be used with it.
• Libraries: Arduino libraries are collections of code that make it easier to write programs for the platform. Libraries are accessible for a variety of purposes, including reading sensor data, controlling motors, and establishing an internet connection.

Video related to PLC vs Arduino

How does a PLC system work?
From connected sensors or input devices, the PLC collects data, processes it, and then starts outputs based on preprogrammed parameters.
Based on inputs and outputs, a PLC can record and monitor run-time data, such as machine productivity or operating temperature. Along with doing other things, it can also initiate and terminate programs automatically and set off alarms in case a machine breaks down. Programmable logic controllers are an incredibly adaptable and dependable control solution that may be used in almost any kind of application.

How does an Arduino work?

1. Link the Arduino board to your PC. For this, a USB cord comes in handy.
2. Install the Arduino software. The Arduino software is available for Windows, macOS, and Linux.
3. Start a new drawing. An Arduino sketch is a program.
4. Set up your PC. The Arduino programming language can be used to create your software.
5. The Arduino board will receive an upload of your software. By using the Arduino software, this is possible.
6. Examine your course. Once your software is uploaded to the Arduino board, you can test it by connecting sensors and output devices.

What is a PLC used for?

• Machine control: PLCs are used to regulate the operation of robots, assembly lines, and packing gear. For example, a PLC could control the speed of a conveyor belt or the workflow of an assembly line.
• Process control: To control the flow of materials such as liquids, gases, and powders, PLCs are utilized. A PLC could be used, for example, to control the temperature of a chemical reactor or the pressure in a hydraulic system.
• Safety control: PLCs are used to operate safety-critical systems, like those that halt potentially harmful equipment operation. A PLC could be used, for example, to turn off a machine if a door is opened while it is operating.
• Data collection: Sensor data can be collected via PLCs and transferred to a computer for processing. For example, a process control system could employ a PLC to collect data on a liquid's temperature, pressure, and flow rate.
• Communication: PLCs may communicate with other PLCs, PCs, and HMIs, among other devices. For example, a PLC could be used to receive commands from a human operator or transfer sensor data to a computer for analysis.

What is an Arduino used for?

• Home automation: You can automate the lights, appliances, and other fixtures in your house using an Arduino. For example, a smart thermostat that adjusts the temperature based on your schedule or the weather can be constructed with Arduino.
• Robotics: Arduino is a popular choice for projects involving automation. It may be used to control many kinds and sizes of robots. For example, a robot that can pick objects up and navigate a maze can be built using Arduino.
• Internet of Things (IoT): You may create online-connected IoT devices with Arduino. For example, you might use Arduino to build a sensor that monitors the temperature in your house and uploads the data to the cloud.
• Education: Arduino is a popular teaching tool for electronics and programming. It's rather easy to learn and use, and there are plenty of tools to help you get started.
• Art and design: Arduino may be used to create interactive art and design projects. For example, you could use Arduino to create a light sculpture that reacts to music or a wearable gadget that records your movements.

Advantages and disadvantages of PLC and Arduino
Advantages of PLC

• Numerous distinct control applications
• Completing the papers was not difficult.
• Programming security to be adaptable enough to changes in production
• PLC is affordable, secure, and has a large number of contacts.
• Solving difficulties by programming and reprogramming
• There are existing input and output interfaces on the controller.
• A programmable logic controller is versatile because it can effortlessly operate several devices.
• A comparatively basic programming language can be used to simply program PLCs.

Disadvantages of PLC

• Certain PLCs start up when the power is restored, which could cause an accident.
• It is challenging to replace or modify items.
• More security precautions are required, including
• Certain PLC applications that perform a single task are inefficient.
• confined spaces High temperatures and vibrations can harm the PLC's electronic components.
• PLC is based on thermal characteristics and is made of semiconductors.
• When PLC is employed, a problem arises; the hold-up period is usually lengthy and unpredictable.

Advantages of Arduino

• Cheap: The cost of Arduino boards is acceptable. If you're very good, you could even build an Arduino module yourself or purchase one assembled for less than $50.
• Flexible enclosure design: The Arduino system is built around a bare integrated circuit board. Modular enclosure architecture. It is possible to mount almost every component of the machinery or process being controlled directly to it. The Arduino controller's housing or enclosure can be constructed from the device it is controlling, or it can be manufactured specifically for it.
• Small and Compact Size: Arduino devices can be placed in almost any available space because of their incredibly low space needs. Additionally, the no-case design exhibits enhanced heat dissipation.
• Open architecture: It utilizes the design of an Integrated Development Environment (IDE), wherein programming facilities and tools—more precisely, the debugging tool, test, and code builder—are combined into a single interface.
• Extremely mobile and portable: Because of their programmable enclosure and incredibly small form factor, Arduino-based gadgets may be able to achieve the highest levels of mobility and portability. One great example of this trait is a miniature robot that can move from one location to another. These robots can maneuver in tight spaces because of their sleek, compact bodies. The majority of these robots are Arduino-based.
• Common accessories and connectivity tools: Accessories are standard home goods. A few of these components are power and communication cables. While pre-made, ready-to-use accessories are readily available, these everyday objects will surely come in handy when ingenuity and personalization are needed.

Disadvantages of Arduino

• Memory: The Arduino board does not have enough memory to store variables and programs. External RAM upgrades are also not possible for it. External memory can be used with the ATmega32 and ATmega128 but their I/O functionalities cannot be used.
• Speed: Compared to most platforms, the Arduino CPU clock rate is much lower, ranging from 8 to 20 MHz. Numerous instructions can be executed during a single clock cycle, meaning that a significant amount of CPU activity needs to be controlled in the intervals between pulses.
• Electrical power: When working with Arduino hardware, voltage settings must be considered because certain components have 3.3V I/O and others are tolerant of 5V. Connecting a 5V transistor-transistor logic circuit to a 3.3V device could harm your Arduino since it would interfere with the hardware.

Conclusion
Process automation can be achieved with both PLCs and Arduinos, which are capable equipment. A project's specific needs will determine which solution is best for it.
If you're looking for a simple-to-use device with a multitude of programming options, Arduino is a great choice. A PLC is a better choice if you're looking for a tool that can handle more complex projects and has greater power.