What is an HMI?

September 17, 2020

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Key Takeaways

A Human-Machine Interface (HMI) empowers operators with real-time asset health data. Let’s take a look at how an HMI streamlines operations and enables a proactive approach to maintenance.

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What is a Human-Machine Interface (HMI)?

A Human-Machine Interface is any user interface or dashboard where operators can interact with a machine, system, or device. In industrial settings, an HMI can also be referred to as the operator interface, man-machine interface (MMI), or operator terminal. Operators and control system engineers rely on HMIs for remote monitoring and control of industrial machines, processes, and manufacturing. For example, water utilities use HMIs to help manage assets that cover a wide geographical area. They can be as simple as a touchscreen display on a machine or as advanced as a multi-touch control panel with mobile compatibility.

While traditional HMIs have provided the primary link between an operator and equipment, because they are localized, they only provide point-to-point access between a single operator and the machine. Any time an operator wants to check a value or update a setting, they must be physically present on-site. This setup also makes sitewide firmware updates cumbersome. Each HMI needs to be updated one at a time manually, which could be time consuming.

In contrast, modern HMIs rely on web-based access and leverage cloud-based platforms. This removes the requirement for an operator to be physically on-site with the equipment. Users can access these HMIs remotely through any device with a web browser. Operators can access real-time data on tank levels, flow rates, pipe pressure, pump power, and run status, all from their smartphone. This minimizes on-site visits, shortens response time to potential issues, and helps organizations avoid costly service interruptions. Cloud-based updates also ensure that the HMI firmware is always current, eliminating the need for manual on-site updates.

How does an HMI work?

An HMI is a key component of Supervisory Control and Data Acquisition (SCADA) systems, a comprehensive platform designed to gather, visualize, and analyze real-time asset and environmental data. SCADA systems and HMIs work together to drive industrial automation and performance improvements across your organization.

To understand how HMIs function, it’s important to first take a brief look at how SCADA systems work. Traditional SCADA systems used proprietary data acquisition methods with closed architectures. These SCADA systems could not communicate across different vendor platforms, and limited access to data due to protocol requirements. Most modern SCADA systems now consist of open system architectures with integrated communications and support for multiple protocols. 

A modern, cloud-based SCADA system uses sensors to collect data on readings such as temperature, vibration, and pressure. These real-time readings are sent to a PLC over a cellular or Wi-Fi connection. After receiving sensor measurements, PLCs will send digital data to the cloud for analysis and reporting in the HMI/dashboard. Operators can remotely view asset data and control set points on industrial equipment. At the touch of a screen, they can set start/stop times, build customizable graphs, view historical trends, and check on alerts.

Common use cases of HMI

You’ll find HMIs used to gain historical and real-time insights in nearly every industrial organization. Here are a few typical HMI applications and the benefits they bring:

  • Gaining visibility and control over water management. According to the United States Environmental Protection Agency (EPA), there are an estimated 240,000 water main breaks and 75,000 sewer overflows each year. From rural areas to big cities, every community relies on water and wastewater treatment companies for a clean, safe, and consistent water supply. Maintaining this critical infrastructure requires continuous monitoring using early detection systems to avoid asset failure. Water companies like Central Texas Water Supply use their HMI dashboard to remotely manage alarms for control pumps, water tanks, and valves.

  • Building out remote monitoring services. Equipment as a service (EaaS) involves original equipment manufacturers (OEMs) and pure play rental companies who manufacture, sell, rent, and service industrial machines to a wide range of organizations. HMI and SCADA systems can help EaaS providers provide enhanced service through remote monitoring and even expand their remote monitoring capabilities to the organizations that rent their equipment, distinguishing them from competitors. For example, Pine Environmental partnered with Samsara in order to offer their customers the ability to configure alerts, resolve potential hazards, and print custom data reports for mission critical activities.

  • Tracking manufacturing processes. For any manufacturing plant, unplanned downtime and high defect rates signal bad news: unhappy customers, lost production time, and expensive repairs. Market research firm Vanson Bourne estimates that unplanned equipment downtime can cost industrial companies as much as $250,000/hour. HMI devices can mitigate downtime by providing real-time analytics and custom alarm management. Operators can record reasons for downtime, establish production targets, and control run times all using an HMI dashboard. This provides actionable insights on specific incidents to ensure proactive maintenance and maximum efficiency.

What are the differences between HMI and SCADA?

While HMI and SCADA work together to drive autonomous operations, they have distinct capabilities:

  • Human-Machine Interfaces refer to any industrial dashboard that allows an operator to communicate with a system or device by showcasing real-time information and controls. Functioning within a SCADA platform, HMI dashboards are the control panels that give users deep visibility into machine health and operations.

  • Supervisory Control and Data Acquisition is the overarching monitoring and control system that is designed to collect, visualize, analyze, and act on real-time data from industrial equipment. While traditional SCADA platforms are complex and difficult to deploy across multiple sites, cloud-based SCADA is winning over industrial organizations with its ease of use and simplified system architecture. SCADA solutions are not complete without the HMI to visualize data for end-users.

5 benefits of modern HMIs

By digitizing real-time data into a user and mobile-friendly screen, modern HMIs eliminate the need for constant walk-arounds and manual documentation. This saves operators time, leaves less room for human error, and allows for a more complete picture of any organization’s operations.

Modern HMI platforms can maximize efficiency and reduce operating costs in five key ways:

1. Build custom dashboards on a user-friendly interface 

Modern HMI platforms with drag-and-drop features allow any number of users to create functional and actionable visualizations tailored to their unique use case. For example, water operators can build dashboards that include granular data on pumps and tank levels. District managers can also utilize high level visualizations to optimize plant performance. Customizable dashboards provide flexibility in the way users receive, view, and interpret operational data.   Traditional HMIs, on the other hand, limit user access to important data by restricting visibility to one operator at a time. This lack of readily available data makes it difficult for off-site managers and operators to quickly diagnose machine issues and manage processes. When considering a modern HMI/SCADA solution, ease of use and personalization should be at the top of the checklist for maximum ROI on HMIs.

2. Access real-time insights and control operations from anywhere through modern cloud-based HMIs

Operators spend much of their time on the go, and their dashboards should move with them. Cloud-based HMIs offer the ability to view and manage every asset from any location, on any device. With operational data at their fingertips, operators don’t have to worry about traveling to a facility to find the cause of an alarm. 

For multi-site managers, cloud HMIs bring peace of mind. At-a-glance dashboards mean less time making on-site visits and more freedom to focus on improving KPIs. Secure cloud storage frees management from having to install on-premise servers as well. This significantly reduces the time and capital cost it takes to roll out an HMI/SCADA solution.

3. Leverage historical data for smart business decisions

HMIs with a built-in historian give important context for operations and technology managers to set and track key performance indicators (KPIs). By allowing users to create custom formulas to track and compare performance metrics in real-time, an HMI with built-in historian capabilities and analytics can help extend asset life, identify early indicators of machine failure, and help organizations prioritize spending.

Deschutes Brewery implemented Samsara’s next-generation HMI/SCADA system to determine whether the necessity of a big investment: spending $750,000 on a second chiller for their main brewery. Real-time power monitoring data streamed directly to Deschutes’ HMI dashboard helped the team understand their current chiller’s health. Vibration readings showed that the existing asset was stable. And by using data to optimize run times and loads, Deschutes was able to prioritize their budget for other more pressing projects. 

4. Improve response time and ensure reliable service

When employee and customer safety are on the line, proactive equipment maintenance is mission critical. Utility companies and Equipment as a Service providers often spend countless hours manually diagnosing issues and checking asset health indicators to ensure everything is in working order.

A modern HMI’s industrial alarm and notification management takes the guesswork out of equipment diagnostics. Operators can set actionable alarms based on custom parameters for every piece of equipment. When operators are alerted of an alarm, the HMI can also provide contextual data to use as an immediate diagnostic tool for the asset in question. This valuable insight enables users to identify false alarms, which prevents unnecessary site visits, and deploy the right response when there is a real issue at hand.

By giving operators advanced warning on potential equipment or process issues, an HMI makes it easier for an organization to adopt a preventative approach to maintenance.

5. Streamline compliance and reporting

From printing production reports to gathering data for compliance, process managers are often flooded with paperwork. It is painstaking to manually keep track of multiple metrics across remote, scattered assets.

Using an intuitive HMI dashboard, managers can consolidate relevant data into a custom report for quick and easy export. Cloud-based HMIs pull real-time data from operations, allowing compilation of minute-by-minute information over any time period.

The future of industrial operations with modern HMIs

Modern HMI technology streamlines the most complex operations by visualizing live process and machine data and making it remotely accessible.

Samsara’s next-generation HMI/SCADA platform combines cloud storage technology with modern hardware for maximum visibility. It’s ready to meet the needs of the most complex operations and fit for rapid deployment. Industrial customers can leverage drag-and-drop dashboards to gain clear visibility into their operations, identify asset failure before it happens, and ensure their services are always up and running.

Interested in trying Samsara’s HMI/SCADA solution? Request a free trial today.


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