Also known as a MMI. A MMI is a software application that present information to an operator or user about the state of a process, and to accept and implement the operators control instructions. Typically information is displayed in a graphic format (Graphical User Interface or GUI). An HMI is often a part of a SCADA (Supervisory Control and Data Acquisition) system. Learn more about SUBNET’s MMI software product SubSTATION Explorer.