HMI software advancement for IIoT optimization

Unified human-machine interface (HMI) software centralizes device management and machine data, enhancing usefulness and increasing connectivity across the enterprise.

By Ramey Miller October 15, 2020


Learning Objectives

  • This new wave of HMI software, running on dedicated devices or PCs, is more attuned with modern smartphones.
  • Collaboration is vital to operational improvement, which unified HMI software supports.
  • HMI software technology must keep pace as everything becomes more interconnected.

Increasingly connected and higher-performing manufacturing plants require corresponding automation advances. While sensors and programmable logic controllers (PLCs) have become smarter over the last decade, not all human-machine interface (HMI) software experienced the same technological boosts. Now, though, the latest generation of HMI software has many advances including:

  • Improved graphical characteristics
  • Onboard productivity applications
  • The ability to connect to a wider variety of devices, and
  • The capability for users to define their own scripts and data pipelines on the HMI’s open platforms.

These advances are optimizing industrial HMIs for use with devices in Industrial Internet of Things (IIoT) applications.

Improved operational technology

Digitalization is no longer a competitive advantage in manufacturing; it is a competitive imperative for profitability, longevity and responsiveness to evolving market trends. Unified HMI software meets these challenges by allowing developers to build sophisticated, responsive, and feature-rich applications suited for the digital age.

This new wave of HMI software, running on dedicated devices or PCs, is more attuned with modern smartphones than with its clunky and antiquated predecessors. Modern unified HMIs ship with preinstalled applications for viewing documents, watching instructional media clips and accessing external web-based systems. Improved multitouch gestures – such as zooming and panning – allow for smooth document navigation and web browsing (Figure 1). Operators can use multitouch swipes to change screens and scroll within lists.

Support for native web technologies like HTML5, scalable vector graphics (SVGs) and JavaScript is increasingly common. This functionality gives developers the ability to customize and animate HMIs, and the move from pixel-based to vector-based graphics improves on-screen aesthetics and machine visualization.

Web server capability allows authorized operators to remotely access HMI applications from any device capable of hosting a web browser – such as a laptop, smartphone or tablet – withoutinstall apps or plugins. This enables opportunities for collaboration between plant-floor staff and engineers in the office, making it easier for teams to troubleshoot issues.

HMI, IIoT collaboration and connectedness

For small machine shops and international enterprises alike, collaboration is vital to operational improvement. To encourage increased collaboration, unified HMI software supports sharing of screens, tags, alarms and production data among multiple devices on the plant floor, which stores all data at a central location (Figure 2). Modern HMI devices also support data transmission over multiple protocols such as message queuing telemetry transport (MQTT) for cloud connections.

Regardless of the plant layout, it is advantageous for manufacturers to consolidate all production data for analysis and process improvement. In the past, each machine type often required its own third-party driver for data transfer to a central location, but unified HMI software overcomes this timeworn obstacle. Built on platforms such as the .NET programming language, unified HMI software system connectivity extends beyond plant-based historians to higher level organizational workflows in manufacturing execution and enterprise resource planning systems.

Developers can leverage the integration of unified HMI software with these workflows to define rules and actions for business processes influenced by triggers from production data. It is also possible to monitor production key performance indicators and include this data in business process reporting. By installing optional apps within a unified HMI software environment, operators can receive production-related mobile alerts and notifications via a parallel app installed on their smartphone, smartwatch, or tablet.

Shared software ecosystem

The key to connectivity across the plant is the unified HMI’s shared software ecosystem. Shared software means one HMI development and runtime environment is used with all visualization devices – control room computers, smartphones, tablets and panel HMIs. All visualization interfaces share a common library of application objects, SVGs and scripts. Because symbols can be reused across device types, it is no longer necessary to spend time and money developing new graphics as plant production expands and additional visualization devices are brought online (Figure 3).

Shared software advantages do not stop at the HMI level. Unified HMI software comes with its own suite of apps, which empower plant owners to modularly select and build out their software infrastructure to suit specific company needs. These apps provide business workflow integration, machine-to-machine (M2M) data exchange, data visualization and analysis, central device management, and other functions.

Central device management – also known as group policy management – is a familiar concept for mobile devices, but it is less common among industrial HMIs. Unified HMI software introduces this capability to enable version control, security patching and app management on HMI devices across the enterprise based on administrator-defined device group rules and assignment. This ensures devices are only used for authorized purposes and protected against security vulnerabilities.

For users, a shared software ecosystem means a similar look and feel across all visualization and control interfaces, including mobile devices. This leads to enhanced operator familiarity and better decision making because less effort is required to understand multiple interfaces, which frees up time to focus on operational improvements. A parallel and intuitive interface across devices also lends itself to less user frustration.

Openness for modern plants

On top of consistency throughout its own software ecosystem, unified HMI software gives users the ability to import custom controls and files. Developers can import objects created with third-party tools into the unified HMI software for deployment in runtime applications (Figure 4). The software’s openness also allows for exchange of large amounts of information with databases and other systems through the use of common .NET and C++ frameworks.

Users also can create open application programming interfaces (APIs) for integration with business and production workflows. Machine builders and end users alike can inject their custom programming into the unified HMI software’s DNA as open APIs. For example, developers can create comparison reports and debugging traces to catch errors in application code or device configurations before they manifest, reducing commissioning time and mitigating machine malfunction risks.

Application openness delivers the accessibility required to analyze data generated throughout the plant, without creating unnecessary inefficiencies or downtime. Runtime openness provides third-party apps with direct access to HMI runtime tags and custom web controls for increased equipment and workflow flexibility.

Offline data collection tools are natively included for submitting data to a designated server. This allows for exchange of large amounts of information with database systems – as well as sharing screens, tags, event archives, and historical alarms.

Security at the core

Gone are the days when security was an afterthought. With breaches picking up in frequency across industry, machine builders and plant owners must treat software security seriously. Unified HMI software comes with several built-in measures for securing against unauthorized machine access.

Unified HMI devices contain separate control panel and runtime layers built on top of the operating system (OS). A system administrator can allow each authenticated user access to one or both layers and also can configure user authorization for OS access. Default applications, user apps and APIs reside on the control panel layer while the runtime layer handles the familiar HMI application for production system control.

An administrator may enable and disable physical ports – USB, Ethernet, and buses – as well as SNMP and transfer protocols. Using central device management, an administrator can create rules for allowing or disallowing certain applications for each device group and manage security patches across all connected devices in the enterprise.

Unlike older HMI software, no third-party central management software is necessary because the same unified HMI software for programming and runtime includes all required tools for central device management. This software also enables device and data integration with other applications. Communication among all devices running unified HMI software is encrypted and HMIs can be configured for automatic system backup to prevent data loss.

These and other features can be used to improve operations. For example, a machine builder was struggling to keep up with growing demands from its stakeholders for greater functionality and usability. The manufacturer recently ceased use of legacy HMI products and installed unified HMI software on its machines to deliver greater performance and flexibility.

This empowered the manufacturer to import its own software and applications for maintenance support, and the many native communication protocols made it possible for users to centrally manage their new device alongside existing machines.

HMIs for the future

As an increasing number of smart devices and enterprise-connected software systems are implemented in industrial plants around the world, HMI software technology must keep pace. Unified HMI software delivers modern graphical interface qualities, while enabling connectivity with a multitude of external devices and software systems.

By implementing these advances and continuing to evolve, manufacturers can maintain a competitive edge, increase production output, and improve efficiency.

Ramey Miller, HMI edge/product marketing manager, Siemens Industry Inc. Edited by Chris Vavra, associate editor, Control Engineering, CFE Media and Technology,


Keywords: HMI, human-machine interface, Industrial Internet of Things


What challenges and considerations do you think are most important when it comes to HMI software?

Author Bio: Ramey Miller is the HMI/Edge product marketing manager for Siemens Industry in the United States. He holds a bachelor’s degree in computer and electrical engineering from Purdue University. Ramey has over 15 years of industrial automation experience, and has been with Siemens for three years.