An HMI is a substantial purchase, so it is important to know exactly what is required of it. An HMI is used for three primary roles: a PUSH button replacer, data handler, and OVERSEER. The push button replacer takes the place of LEDs, On/ Off buttons, switches or any mechanical device that performs a control function. The elimination of these mechanical devices is possible because the HMI can provide a visual representation of all these devices on its LCD screen, while performing all the same functions. The Data Handler is used for applications that REQUIRE constant feedback and monitoring. Often these Data Handlers come equipped with large capacity memories. The last of the HMI three types is referred to as the overseer, because it works with SCADA and MES. These are centralized systems that monitor and control entire sites or complexes of large systems spread out over large AREAS. An HMI is usually linked to the SCADA SYSTEM's databases and software programs, to provide trending, diagnostic data, and management information.

An HMI is a substantial purchase, so it is important to know exactly what is required of it. An HMI is used for three primary roles: a push button replacer, data handler, and overseer. The push button replacer takes the place of LEDs, On/ Off buttons, switches or any mechanical device that performs a control function. The elimination of these mechanical devices is possible because the HMI can provide a visual representation of all these devices on its LCD screen, while performing all the same functions. The Data Handler is used for applications that require constant feedback and monitoring. Often these Data Handlers come equipped with large capacity memories. The last of the HMI three types is referred to as the overseer, because it works with SCADA and MES. These are centralized systems that monitor and control entire sites or complexes of large systems spread out over large areas. An HMI is usually linked to the SCADA system's databases and software programs, to provide trending, diagnostic data, and management information.