HMI or Human Machine Interfaces are used in the manufacturing industry to control and monitor machines. A very common example would be an ATM, whose screen and pushbuttons allow you to interact and control the machine so that you can receive or deposit money.
In Industrial Automation, HMIs most commonly come in the form of screens that allow an operator to monitor and interact with the machines on the factory floor. It may convey important information such as pressure, temperature, and process steps all in one centralized location, making it easy for maintenance personnel to track and monitor the machine. The information shared on the HMI to the operator is only limited by the hardware and software used.
For maintenance personal HMIs are utilized by connecting to PLC logic so the processes and information can be displayed onscreen for troubleshooting purposes. This helps to save valuable time, so the operator doesn’t have to connect a laptop or computer to the machine to find out what is going on every time a problem occurs. Another benefit is that large plants and other industrial sites can monitor and control multiple remote machines or other equipment with even a small manufacturing facility being able to monitor the entire plant from one centrally located HMI.
The HMI itself is comprised of an operation panel and a monitoring screen. HMIs use special software that allows engineers to properly program them for the specific task they need to undertake. This software is often proprietary and specific to the company that manufactured the HMI meaning, only the manufacturer’s software can be used to interface or program that manufacturer’s specific HMI. This further means that any subsequent PLC logic that is used in conjunction with the HMI needs to be compatible, or use the same proprietary software from the manufacturer, in order to be able to talk to each other and work efficiently.
The software allows the design engineer to decide exactly how the operator and machine will interface by determining exactly what specific machine information will be displayed on the screen and how the operator will be able to interact with that information on the screen in order to interact with it. In industry terms, the PLC and HMI need to run on the same protocol such as Modubs, Ethernet/IP, and Profibus (i.e different types of industrial networks). These protocols therefore act as the foundation of the network that connects the PLC to the HMI and other ancillary devices so they can talk together.
Now that you have a better understanding of HMIs and their role in running, controlling, and monitoring industrial automation equipment and machines, check out MISUMI’s new offering of HMI products from such reputable brands as Mitsubishi Electric, Maple Systems, and Proface here.