What is an HMI?

One of the most common components on any large machine is an HMI or 'human machine interface.' These are often touchscreens built into an electrical panel on the side of a machine. You will often see a number of buttons and switches that below it designed for an operator to reset a machine after a safety has been tripped, a setting has been changed, and to stop and start in a controlled manner.

The screen itself will typically have a variety of information. On a box erector it may show the name of the box size it's currently running, as well as the numerical values that the various servos are set at. I always advise taking pictures of a screen before touching it, on the off chance you make a change that makes the machine run in a way that's undesired.

Depending on the machine, the normal operator may have a few options for making changes. Things such as changing recipe or size of the product. Pressing these buttons will change the machine into the state needed for the new incoming product.

Advanced settings are reserved for trained personnel, usually only mechanics, but sometimes managers in other departments. These advance settings are buried in hidden menus that need a password to see and access. The default password is typically in the manual of the machine, but a well-run department will have custom passwords so that access is limited to those who have a deeper understanding of the more nuanced programming.

Thanks to IoT or the 'internet of things' some of these HMIs are accessed through the internet. They typically behave the same way as one located on the machine. The benefit though is that it can be accessed without physically being on location. This can be very helpful for troubleshooting since most HMIs will have a graphical display of the machine. During a problem, such as a jam or overload, it may even show the exact location. Someone on the computer can call over the radio what section of a conveyor has an overloaded motor to a mechanic on site. The mechanic can do what repairs are needed and radio back to check if the HMI is clear.

Get comfortable with working with HMIs. They aren't going anywhere. They will help your work immensely.