User Interface vs Human Machine Interface: What's the Difference?
If you keep up with our blog here at Nelson-Miller, you are probably well aware of the general concept of human machine interfaces (HMI). Consisting of an interface that allows the communication between a human operator and machine, HMIs are used in just about every industry and sector under the sun, including telecommunications, manufacturing, retail, food service, medical and aerospace (just to name a few). But how exactly does HMI differ from a user interface (UI)?
Computer Systems and Electronic Devices
While there are always exceptions to this rule, user interfaces are typically used to describe the interface of a computer, computer system, or similar electronic device. This is in stark contrast to human machine interfaces, which are typically used to describe the interface of a machine or industrial device. Again, there are exceptions to this rule, but you'll usually find UIs being used in computers and electronic devices.
Locality to a Single Machine
Another distinguishing characteristic that separates human machine interfaces from user interfaces is locality. Human machine interfaces are usually local to a single machine or piece of equipment. The HMI may still be connected to a larger network for the purpose of reading data, but the actual interface usually only controls a single machine or piece of equipment. User interfaces, on the other hand, may control several different computers or electronic devices.
Interface Design
The actual design of a human machine interface usually consists of mechanical components and membrane keypads, whereas user interfaces are designed with an emphasis on digital controls. For instance, a user interface may support digital touchscreen commands via a computer. A human machine interface may feature a membrane keypad that's connected to a machine display.
