A human machine interface (HMI) is a type of user interface that controls a manufacturing machine or equipment. They typically consist of hardware and software components, each of which are equally important in its function. While all HMIs feature this similar design, there are two different types of HMIs: human-to-machine and human-to-human. So, what’s the difference between human-to-machine and human-to-human HMIs?
As the name suggests, human-to-machine HMIs allow a human operator to control a machine, whereas a human-to-human HMI allows a human operator to monitor or control the processes of other human workers. With that said, the de-facto definition of an “human machine interface” specifically refers to the former. Human-to-human HMIs are more of a segment. And as such, they generally aren’t covered when talking about HMIs.
Some people assume that HMIs are the same as user interfaces, but this isn’t necessarily true. An HMI is defined as an interface through which a human operator controls a machine. In comparison, a user interface is a graphical interface through which a human operator or a machine controls a machine. The interface of an HMI could be physical or virtual (or both), whereas the interface of a user interface is almost always graphical. Understanding these concepts will help you grasp the purpose of HMIs.
So, what benefits do HMIs offer? Because they are used in industrial applications, they can prove invaluable in helping companies improve their production processes. With integrated HMIs, industrial companies can identify bottlenecks, improve production times, reduce waste, create a safer working environment and more.
HMIs are often comprised of components like touchscreens and membrane switches. Touchscreens allow users to control the HMI through touch-based commands. Membrane switches serve a similar function but operate using traditional electrical switches. Some HMIs feature only touchscreens, others have only membrane switches, and yet some contain both touchscreens and membrane switches. Regardless of the components used in its construction, however, all HMIs are designed to control a machine or process through a convenient interface.
To recap, human-to-machine HMIs serve as an interface through which a human operator controls a machine. A human-to-human HMI, on the other hand, is an interface through which a human operator monitors or controls the processes of other workers. Generally speaking, human-to-machine HMIs are the only true HMIs. A human-to-human HMI by definition isn’t necessarily an HMI. Hopefully, this gives you a better understanding of HMIs and how they operate.
