HMI and operator interface products provide the visual and interactive layer between personnel and industrial control systems. Their architecture typically combines a display, touch or keypad input, embedded processing, communication interfaces, application memory, power circuitry, and a panel-mounted enclosure. Product families can include touchscreen terminals, keypad terminals, operator panels, and integrated display stations. Technical characteristics vary by model and include screen size, resolution, color capability, input method, supply voltage, memory, network protocol, environmental rating, and controller compatibility. Functionally, these interfaces display process values, alarms, trends, machine status, and operating screens while sending operator commands to connected controllers. Replacement selection should match the original HMI family, display format, communication option, power specification, hardware revision, and compatibility with the existing application software.
