What are HMIs? Know some basics of HMI or Human Machine Interface

HMI is an acronym for Human Machine Interface. We use HMI in industry to control and monitor equipment. You often encounter a common HMI is an ATM machine.

The screen and buttons allow you to operate the machine to complete withdrawals or deposits. Industrial HMI Now let's talk about industrial HMI. Without HMI, it is difficult to realize automation control in the industry.

HMIs usually come in the form of screens, like computer screens, and sometimes more touch screens. Operators or maintenance personnel can operate and monitor equipment from the HMI. They may include information such as temperature, pressure, process steps and material counts.

They can also show the exact height in the tank and the precise location of the equipment. Data from multiple devices can now be viewed on one screen. Specific implementations are limited to specific software and hardware.

Advantages of Industrial HMI For maintenance personnel, many HMIs can also connect to a PLC and display its data on a screen for troubleshooting. This saves valuable time compared to connecting to a computer or laptop each time. Another benefit of having a modern HMI is that factories and other industrial locations can monitor and control multiple machines or other equipment.

A small manufacturing plant can even monitor the entire plant from one centrally located HMI. For many years, water systems and wastewater treatment facilities have used HMIs in conjunction with PLCs. Ability to remotely monitor locations such as water pumps and equipment within factories.

By now, you probably understand that HMIs are operator panels and monitoring screens. But how does the HMI actually connect to the machine for control and monitoring? Let's see. First, HMIs use specialized software that engineers can program.

Different brands of HMI use different software. On the software, engineers can design what they actually see on the screen, monitor data on the screen, and design "buttons" to realize operational control. For example, an HMI might display a large water tank on the screen, showing the fluid level.

Next to the tank is a water pump to control the liquid level. The HMI can also display start and stop buttons on the screen next to the pump and allow access to that. This button turns the pump on and off.

However, it's not as simple as putting a button on the screen, or a tank with a level on the screen. The HMI programmer must program each indicator and button into a designated register address in the PLC. This brings up another point, that the HMI and PLC need to be compatible.

This means they need to enable interaction. They perform operations according to so-called protocols. Different companies use different protocols.

Common protocols are Modbus, Ethernet/IP and Profibus. These are all industrial communication networks, kind of like the network in your house where you have multiple computers, TVs or other devices connected to each other. As long as the PLC and HMI can interact, the PLC functions can be monitored and controlled using the instruction data programmed in the HMI.