Gone are the days of HMIs merely consolidating switches, pushbuttons, meters, and operator warning lights. Today’s HMIs now control machines and even whole production lines with functions to analyze and optimize operations.
Some serve as the processor for I/O signals providing feedback on speeds, temperatures, torque, tension, and more to optimize processes. Here, HMIs provide global insights based on myriad edge devices — those motor-feedback devices, transducers, sensors, and other smart components (such as smart motors or smart bearings) fitted with electronics to communicate current states. Other variations put HMI functionality right on the motion and other automation devices themselves. In fact, HMIs assume many of the tasks associated with legacy distributed control systems or DCSs. Refer to Design World’s literature on controllers (motion, PLC, PC, and PAC) for more on this.
As the effect of Moore’s Law shows influence on the advancement of electronic-display technology, today’s HMIs also assume all processing for the presentation of human-readable information about machines and automated operations. In fact, the task of processing data for human-readable readouts is something industry now takes for granted. Communications with machine controllers are also standard; many hardware iterations have yielded to software for executing communications-related tasks. Low-cost and free drivers abound. Here, the main decision design engineers may face is choosing between integrated options or ever-more-common Ethernet, fieldbus, or simple and cost-effective serial communications.
Open-source modules and easily configurable HMIs let designers use programming software for quick setup and customization. Templates allow configuration for collection of networked-machines’ data — and then navigation layouts to allow HMI end users (on the plant floor or elsewhere) to access all of those data streams in a logical way.
In fact, HMIs are core components in the industrial IoT, IT/OT convergence, and overall integration of plant operations with enterprise-level management. They can give machine operators detailed information on one running machine cycle; send workers and plant supervisors statistical analysis of throughput; replace printed paper charts on facility bulletin boards; and grant plant managers remote access to global data from smartphones and mobile devices. In fact, many HMIs filter data upfront for its ultimate destination and authorized audience.