What is an HMI?
A human machine interface also known as a user interface, or HMI is a software application that presents information to an operator about the state of a process and to accept and implement the operator control instructions. In simpler terms, HMI connects a person to a machine, system or device.
Information is then presented in a graphic format (Graphic User Interface or GUI). An HMI is usually part of a Supervisory Control and Data Acquisition (SCADA) system.
(SCADA? These are centralized systems that monitor and control entire sites of large systems spread out over large areas. An HMI is usually linked to the SCADA system’s databases and software programs).
Different types of HMIs
There are three basic types of HMI:
1- The Push Button Replacer
It streamlines the manufacturing processes by centralizing all the functions of each button into one location. It takes the place of LEDs, On/Off buttons and switches. The elimination of these mechanical devices is possible since the HMI can provide a visual representation of all the devices on its LCD screen, while still performing all the other functions.
2- The Data Handler
This type of HMI is perfect for applications that require constant feedback from the system. They often come equipped with large capacity memories. One must ensure that the HMI screen is big enough for things like graphs, production summaries, and visual representations. It includes functions such as recipes, data logging, and alarm handling.
3- The Overseer
An overseer HMI is essential in any application that involves SCADA. The HMI will most likely need to run Windows and have several Ethernet ports.
What Programming Software to Use/Choose?
There are three main categories to choose from:
1- Proprietary Software
This is the software the manufacturer provides which is easy to use and allows for quick development.
2- Hardware-Independent Software
This is third-party software that is developed to program on different types oh HMIs. It gives the developer much more freedom for HMI selection.
3- Open Software
It allows the developer to have complete openness in the design process and should only be selected by an advanced programmer.
Who uses Human Machine Interface?
HMI technology is used by almost all automation industries as well as a wide range of other companies to interact with their machines and optimize their industrial processes.
Applications of Human Machine Interface
Different applications of Human Machine Interface are:
- Utility companies may use HMIs to monitor water distribution and wastewater treatment.
- They are used in bottling processes to control all aspects of the manufacturing line such as speed, error detection/correction, and efficiency.
- In metal manufacturing, an HMI can control how metal is cut and how fast it is cut.
Advantages of Human Machine Interface
The major advantages of HMI are:
- An HMI can reduce the cost of production.
- Improved efficiency and productivity.
- It enables more work to be done in lesser time. This may potentially increase profit margins.
- Due to their ability to save a lot of data, they come in handy since that data can be used later for other purposes, like, troubleshooting future mechanical problems.
- HMI devices are now extraordinarily innovative and capable of higher capacity and more elaborate, interactive functions than ever before. They offer technological advantages such as; eliminating the need for mouse and keyboard, converting hardware to software.