What is HMI, Common Uses, Trends, and the Future of HMI
HMI Defined
A Human-Machine Interface (HMI) is a user interface or dashboard that connects a person to a machine, system, or device. While the term can technically apply to any screen allowing user interaction with a device, HMI is most commonly used in the context of industrial processes.
HMIs are similar to Graphical User Interfaces (GUIs) but are not synonymous; GUIs are often utilized within HMIs for visualization capabilities.
In industrial settings, HMIs can be used to:
- Visually display data
- Track production time, trends, and tags
- Oversee KPIs
- Monitor machine inputs and outputs
For example, just as you might interact with your air-conditioning system to check and control the temperature in your house, a plant-floor operator might use an HMI to check and control the temperature of an industrial water tank or to see if a particular pump in the facility is currently running.
Basic HMI examples include built-in screens on machines, computer monitors, and tablets. Regardless of their format or the term used to refer to them, their purpose is to provide insight into mechanical performance and progress.
Who Uses HMI?
HMI technology is utilized by almost all industrial organizations, as well as a wide range of other companies, to interact with their machines and optimize their industrial processes.
Industries using HMI include:
- Energy
- Food and beverage
- Manufacturing
- Oil and gas
- Power
- Recycling
- Transportation
- Water and wastewater
And many more
The most common roles that interact with HMIs are operators, system integrators, and engineers, particularly control system engineers. HMIs are essential resources for these professionals, who use them to review and monitor processes, diagnose problems, and visualize data.
Common Uses of HMI
HMIs communicate with Programmable Logic Controllers (PLCs) and input/output sensors to gather and display information for users. HMI screens can be used for a single function, like monitoring and tracking, or for more sophisticated operations, like switching machines off or increasing production speed, depending on how they are implemented.
HMIs optimize industrial processes by digitizing and centralizing data for users. By leveraging HMI, operators can view important information displayed in graphs, charts, or digital dashboards, manage alarms, and connect with SCADA, ERP, and MES systems, all through one console.
Previously, operators would need to walk the floor constantly to review mechanical progress and record it on a piece of paper or a whiteboard. By allowing PLCs to communicate real-time information directly to an HMI display, HMI technology eliminates the need for this outdated practice, reducing many costly problems caused by lack of information or human error.
What is the Difference Between HMI and SCADA?
Supervisory Control and Data Acquisition (SCADA) and HMI are closely related and often mentioned together since they are both part of a larger industrial control system. However, they offer different functionalities. HMIs focus on visually conveying information to help users supervise an industrial process, while SCADA systems have a greater capacity for data collection and control-system operation. Unlike SCADA systems, HMIs do not collect and record information or connect to databases. Instead, HMI provides an effective communication tool that functions as part of or alongside a SCADA system.
Developing Trends in HMI Technology
Over the past decade, changing operational and business needs have driven interesting developments in HMI technology. It is now common to see evolved forms of HMI, including high-performance HMIs, touch screens, and mobile devices, alongside more traditional models. These modernized interfaces are creating more opportunities for equipment interaction and analysis.
High-Performance HMIs
Operators and users are increasingly moving toward high-performance HMI, a design method that ensures fast, effective interaction. This approach highlights the most necessary or critical indicators on the interface, helping the viewer to see and respond to problems more efficiently and make better-informed decisions. Indicators on high-performance HMIs are simple, clean, and purposely cleared of any extraneous graphics or controls. Other design elements, like color, size, and placement, are used with discretion to optimize the user experience.
Touch Screens and Mobile Devices
Touch screens and mobile devices are modern advancements in HMI technology that have emerged with the advent of smartphones. Instead of using buttons and switches, modern HMIs allow operators to tap or touch the physical screen to access controls. Touch screens are particularly significant when paired with mobile HMI, which can be deployed through web-based HMI/SCADA or via applications. Mobile HMI provides operators with instant access to HMI information and enables remote monitoring.
Remote Monitoring
Mobile-friendly remote monitoring offers greater flexibility and accessibility for both operators and managers. This feature allows, for instance, an offsite control system engineer to confirm the temperature of a warehouse on a portable device, eliminating the need for onsite supervision after working hours. Soon, checking on a factory floor process while being miles away from the facility will become routine.
Edge-of-Network and Cloud HMIs
Edge-of-network HMIs are in high demand because they enable operators to access data and visualization from field devices. Additionally, it is increasingly common to send data from local HMIs to the cloud for remote access and analysis, while maintaining local control capabilities.
Peering into the Future of HMI
Looking ahead, leading engineers are exploring ways to implement Augmented Reality (AR) and Virtual Reality (VR) to visualize manufacturing functions. As data becomes increasingly crucial in manufacturing, the future of HMI is promising, with virtually limitless potential for growth.
