Comprehensive Guide to HMI Screens: Types, How to Choose, Usage, Advantages, and Disadvantages

Dear automation enthusiast!

Welcome to the fascinating world of Human Machine Interface (HMI) screens! These remarkable devices play a vital role in modern industrial systems, serving as the interface between humans and machines. Their intuitive and user-friendly designs empower operators to interact efficiently with complex machinery, ultimately boosting productivity.

In this blog post, we will delve into the realm of HMI screens to help you understand the various types available and guide you in selecting the most suitable one for your industrial application. As technology advances, the options in HMI screens have expanded, making it essential to stay informed about their associated advantages and disadvantages.

So, gear up, embrace the magic of technology, and let's embark on this enchanting journey through the world of HMI screens. Remember, in this mystical realm, knowledge is the key to unlocking the power of automation. Let's wizard our way through, one line of code and one touchscreen tap at a time! 😄✨🧙‍♂️✨

 

How does HMI operate?

The principles of how HMI screens work on the hardware side involve the following key components and processes:

1. Display: The HMI screen features a visual display, which can be an LCD (Liquid Crystal Display), OLED (Organic Light Emitting Diode), or similar technology. This display serves as the user interface, presenting information, graphics, and controls to the user.
2. Touch Sensors: HMI screens are equipped with touch-sensitive panels, often based on technologies like capacitive touch or resistive touch. When the user touches or interacts with the screen, these sensors detect the input and convert it into electrical signals.
3. Microcontroller: Inside the HMI screen, there is a microcontroller or processor responsible for managing the touch sensors and handling user inputs. It processes the signals from the touch sensors and interprets the type of interaction (tap, swipe, etc.).
4. Display Controller: The display controller manages the screen output, controlling what information and graphics are shown on the display based on user inputs and the application's logic.
5. Communication Interface: In more advanced HMI screens, there might be communication interfaces (e.g., RS-232, Ethernet, USB) to connect with other devices or systems, enabling data exchange and control functions.
6. Power Supply: HMI screens require power to operate, and they are usually connected to a power source or powered by batteries.

When a user interacts with the HMI screen, the touch sensors detect the input, and the microcontroller processes this data. The microcontroller then translates the user's actions into specific commands or data, which are sent to the machine or system the HMI is connected to. These commands can trigger various actions, like starting or stopping a process, changing settings, or displaying relevant information.

In summary, HMI screens work by using touch sensors to detect user inputs on a display. The microcontroller processes the input data and communicates with other devices or systems to execute the desired actions based on the user's interactions. This enables users to interact with machines and systems in a user-friendly and intuitive manner.

Types of HMI Screens:

1. Touch Screen HMIs: Touch screen HMIs are one of the most popular types used in various industries. They offer a user-friendly interface, allowing operators to interact directly with the displayed elements by tapping, swiping, or dragging. These screens often come in resistive and capacitive variants, each with its advantages and disadvantages.
• Resistive Touch Screens: These are cost-effective and work with both gloved and ungloved hands. However, they are less durable than capacitive screens and may require occasional calibration.
• Capacitive Touch Screens: Known for their responsiveness and durability, capacitive screens offer a smoother user experience. However, they are sensitive to touch, which may lead to accidental inputs.
2. Keypad HMIs: Keypad HMIs consist of physical buttons and keys that allow operators to input specific commands or access predefined functions. They are ideal for applications where touch screen interaction may not be practical, such as in harsh environments or with heavy-gloved hands.
• Membrane Keypads: These are cost-effective and offer good protection against moisture and dust. However, they can wear out over time and may lack tactile feedback.
• Mechanical Keypads: More durable than membrane keypads, mechanical keypads provide tactile feedback, enhancing user experience. Nonetheless, they are bulkier and may be more expensive.

 

How to Choose the Right HMI Screen?

 Selecting the most suitable HMI screen for your application involves careful consideration of various factors:

1. Application Requirements: Analyze the specific needs of your industrial process. Consider factors such as the type of industry, the nature of the process, and the criticality of the operations. For example, if you are working in a food processing plant with high sanitary requirements, you might need an HMI screen with a stainless-steel enclosure and IP69K protection to withstand frequent washdowns and ensure hygienic conditions. On the other hand, if your application involves heavy machinery in a rugged environment, you'll need an HMI screen designed to withstand extreme temperatures, shocks, and vibrations.

2. Display Size and Resolution: Choose an appropriate screen size and resolution that provides clear visualization of information without overwhelming the operator. Consider the viewing distance and the amount of data that needs to be displayed. For instance, in a control room, a larger screen with higher resolution might be suitable for displaying complex data, while in a compact control panel, a smaller screen with lower resolution can be more practical.

3. User Interface (UI) Design: Ensure the HMI screen's software allows for intuitive and efficient UI design, optimizing the operator's experience and productivity. Look for HMI software that offers customizable widgets, drag-and-drop functionalities, and a library of pre-built templates. The interface should be easy to navigate, and the touchscreen should be responsive to touch inputs.

4. Connectivity Options: Consider the communication protocols supported by the HMI screen to ensure seamless integration with your industrial equipment. Common protocols include Modbus, Ethernet/IP, Profibus, and Profinet. Check if the HMI screen can communicate with PLCs, sensors, and other devices used in your application. It is also essential to confirm that the HMI screen can handle data exchange in real-time to provide accurate and up-to-date information to operators.

5. Durability and Robustness: Assess the level of protection against environmental factors such as water, dust, vibrations, and temperature fluctuations, based on your application's demands. The HMI screen should comply with industry standards for protection, such as IP65 or higher for dust and water resistance. Additionally, look for HMI screens with rugged enclosures and hardened touchscreens to withstand harsh conditions.

6. Lifecycle and Support: Look for reputable manufacturers offering long product lifecycles and reliable customer support to avoid unnecessary downtime. Investing in an HMI screen from a well-established manufacturer ensures that you can get spare parts, software updates, and technical assistance throughout the life of your application. Consider the manufacturer's reputation for product reliability and their commitment to providing timely support.

By carefully considering these factors, you can make an informed decision and choose the right HMI screen that not only meets your current requirements but also offers long-term reliability and performance in your industrial application. 

 

Advantages of HMI Screens:

1. Enhanced Operator Efficiency: HMI screens simplify complex processes, reducing the learning curve and enabling operators to perform tasks more efficiently.
2. Real-time Monitoring and Control: HMI screens provide real-time data, allowing operators to monitor the system's performance and make prompt adjustments when necessary.
3. Centralized Control: Multiple functions can be integrated into a single HMI screen, reducing the need for multiple physical controls and minimizing clutter.
4. Data Logging and Analysis: HMI screens often include data logging capabilities, enabling operators to review historical data and analyze trends for process improvement.
5. Remote Access and Diagnostics: Some HMI screens support remote access, allowing operators to monitor and troubleshoot systems from a distance.

Disadvantages of HMI Screens:

1. Initial Investment: Acquiring and implementing HMI screens can involve a significant upfront cost, especially for large-scale installations.
2. Potential Technical Failures: As with any electronic device, HMI screens are susceptible to technical malfunctions, which could impact operations.
3. Security Risks: If not adequately secured, HMI screens could be vulnerable to cyberattacks, potentially compromising sensitive industrial data.
4. Dependency on Technology: Relying heavily on HMI screens may create dependency on technology, making it crucial to have backup procedures in case of failures.

 

Conclusions

Choosing the right HMI screen is pivotal in achieving optimal performance, efficiency, and operator satisfaction in industrial settings. By considering factors like application requirements, display type, and connectivity options, businesses can make well-informed decisions to select the most suitable HMI screen for their needs. Understanding the advantages and disadvantages of HMI screens enables industrial enterprises to strike the right balance between enhanced productivity and potential challenges, paving the way for seamless integration and improved human-machine interaction.

And now, for the grand finale, a joke to tickle your funny bone: 

Why did the HMI screen break up with its user? 

Because the user kept pressing all the wrong buttons, and the poor HMI screen just couldn't take the emotional stress anymore! It's all about user-interface compatibility, folks!

So, gear up, embrace the magic of technology, and let's embark on this enchanting journey through the world of HMI screens. Remember, in this mystical realm, knowledge is the key to unlocking the power of automation. Let's wizard our way through, one line of code and one touchscreen tap at a time! 😄🔮✨

 

One more thing 😉

Unlock the power of industrial innovation with PartsNL's we can offer ready-to-use, affordable used HMI screens! Our sustainable solutions are designed to meet your requirements while minimizing electronic waste. Get in touch via our contact form for more details. Let's transform your projects together!