HMIs & Operator Displays
HMI is the acronym for Human Machine Interface which, simply put, is an interface between a user and a machine. HMI is a term specific to manufacturing and process control systems. An HMI provides a visual representation of the status of a control system with real-time data acquisition.
HMI's can also act as the centralized control unit for manufacturing lines as they are usually equipped with non-volatile memory containing data recipes, can execute event logging and event triggering, and can provide video feed for status monitoring. For a manufacturing line to be integrated with an HMI, it must first be connected to a Programmable Logic Controller (PLC) or Motion Controller. It is the PLC/Motion Controller that takes the information from the machine sensors and converts it into Boolean algebra to communicate with the HMI.
The greatest advantage of an HMI is its user-friendliness and ability to personalize its graphical interface. An HMI can fully support complex applications with multiple screens and several routines running concurrently. Every HMI comes with different features; some may play sound, play video, or even have remote access control. The selection of an HMI should be optimized for a customer's specific application taking into consideration the capabilities of the typical user, as well as the environmental conditions such as noise, lighting, dust, vision, etc.