Role of Human Machine Interfaces (HMI) in Industrial Automation

Human Machine Interfaces (HMI) are used in industrial automation to display key metrics and controls to regulate an automated process. They communicate with PLCS, SCADA, and other automated systems. HMIs can be found in more than industrial settings, but the industrial setting is the most common.

Are you trying to understand how industrial automation works? Perhaps you are trying to prepare yourself to speak with an automation contractor about human machine interfaces (HMIs). 

Keep reading to learn more about the role of Human Machine Interfaces in industrial automation! When you finish, learn more about the pros and cons of industrial automation.

This Access Industrial Automation blog post aims to help you understand what HMIs do, what types of HMIs there are, and how to choose an HMI. We’ll also answer frequently asked questions.

If you need a broader overview of technologies used in automation, keep reading here.

What Human Machine Interfaces (HMI) Do

Human Machine Interfaces (HMI) allow operators to interact with an automated system by communicating desired controls to the rest of the automated system. Operators can use an HMI to stop or start a process, adjust functions, and view and manage alarms.

Here’s a more comprehensive list of the role that human machine interfaces play in industrial automation.

  • Stop and start processes
  • Display data in a visual manner
  • Monitor and communicate production times
  • Track trends and tags
  • Key Performance Indicators
  • Monitor and regulate inputs and outputs 
  • View and manage alarms
  • Connect with PLCs, SCADA, and other automation elements

Difference Between Human Machine Interfaces (HMI) and Supervisory Control and Data Acquisition (SCADA)

Supervisory Control and Data Acquisition Systems (SCADA) are different from human machine interfaces (HMI). SCADA has more capacity for data acquisition and control of the entire system. High-performance HMIs focus on only the specific information and controls needed at the access point.

SCADA refers to a larger operating system. Many say that SCADA includes all of the software and hardware of an automated system. Using that broad definition, the HMIs would be a piece of the larger picture.

Types of Human Machine Interfaces (HMIs) in Industrial Automation

A human machine interface can be any piece of technology that displays relevant information and controls for an operator in industrial automation. While HMIs can be computers and monitors, they can also be touch screens, built-in screens with controls, tablets, mobile devices, or more.

  • Built-in screens on machines: These may be touch screens, or they may be a simple display with controls along the perimeter or side.
  • Tablets: Tablets are an increasingly common method that industrial plants use. The appropriate operator uses a tablet with the necessary functions to stop, start, and adjust processes.
  • Computers and monitors: An operator may use a computer and monitor to perform their duties and interface with the machines.
  • Touch screens: Touch screens may be built into the machinery, or they may be portable like a tablet. The integration of visual information and controls makes touch screens a desirable option for HMIs.
  • Mobile devices: Mobile devices are an HMI option growing in popularity because of their remote capabilities. Mobile devices can stop, start, and adjust processes conveniently from almost anywhere.
  • Edge-of-Network HMIs: Edge-of-Network HMIs are gaining traction in the industrial automation sphere because operators can access controls and data in the field on the edges of the network.
  • Cloud HMIs: Cloud HMIs allow data to be accessed an analyzed from the cloud without disrupting local control of the automated processes.

What’s Next in Human Machine Interface Technology

Human Machine Interface (HMI) technology is progressing to include virtual and augmented reality components. The possibilities for interfacing with machines is limitless. Since HMIs include so many different technologies, the concept is never going to disappear.

Choosing a Human Machine Interface (HMI)

Choosing a Human Machine Interface (HMI) is a decision that can be made with an automation contractor. A contractor will help you determine if you want or breed remote access, how to optimize the performance of HMIs, and other considerations like how harsh the industrial setting is.

High Performance Human Machine Interfaces (HMIs)

High performance Human Machine Interfaces (HMIs) streamline the display and control options on any given HMI. This focus on only the most necessary and critical function simplifies the process to make it more efficient. 

The design features on high performance HMIs remove unimportant features, images, and graphics. This enhances the operators’ decision-making abilities with less distraction and information overload.


Human Machine Interfaces allow human operators to communicate with the machines in industrial automation. HMIs can be built-in or as mobile as a phone or tablet. HMIs can have streamlined functions and designs or more sophisticated features. 

To consult with an automation contractor in central California, contact AI Automation online or by calling 209-577-1491. We gladly serve Fresno, Modesto, Stockton, and the surrounding communities.

Learn more about Remote Terminal Units (RTU) on our blog.

Want even more information about the automation process? Learn more about the importance of systems integration.

Frequently Asked Questions

Are HMIs necessary for industrial automation?

Human Machine Interfaces (HMIs) are necessary for human operators to stop, start, or adjust automated processes. HMIs are a key component of industrial automation and can allow for local or remote control of the machines.

What is an interface between humans and machines?

One example of an interface between humans and machines is a thermostat. The thermostat in a home or building allows a human to stop, start, or adjust the heating and cooling settings of the HVAC system.

What’s the role of HMIs in SCADA?

Human Machine Interfaces (HMIs) are operating points in the automated system, which is usually overseen on a larger level by Supervisory Control and Data Acquisition (SCADA) Systems. SCADA collects more data and implements more control over the system as a whole than an individual HMI.

Leave a Reply

Your email address will not be published. Required fields are marked *