Four signs it's time to replace your HMI unit

09/18/2015
by Qualitrol Support Team

Your Human Machine Interface (HMI) units are crucial to running your business. They enable successful and easy operation of your machines and they replace more complicated units with hundreds of buttons and switches in your manufacturing plants. The frequent use of these interfaces make them susceptible to breaks, screen failures, and other problems.

It’s essential to use your interface correctly because over time, the unit can show signs of heavy use and become unreliable. How do you know when it’s time to replace your HMI unit?

1. Screen is not properly lit

If your screen isn’t properly lit, is difficult to see, or if the graphics are not properly displayed, this could mean your backlights or inverter circuit are faulty or the display may need to be replaced. In some HMIs, the lights that are responsible for lighting the display get so hot that they melt the fiber optic cables and cause the screen to dim or be “patchy” in places. When this happens, the screen essentially loses its functionality and is no longer safe to use, as improper selections could be made. This could cause your machines to malfunction, your equipment to be damaged, or even put your operator at risk of injury.

2. Touch screen is no longer responsive

When your touchscreen doesn’t let you make selections anymore, you know it’s time to replace your HMI unit. You may have to press really hard or try several times to make a selection. When this happens, it could be the result of excessive use, poor connection, or loss of calibration, but regardless of the reason, your touchscreen is defective. The performance of your touchscreen could be affected by buildup of things like dirt, grease, or other substances. Misalignment of the touchscreen could affect your accuracy when making selections as well.

3. Faulty cable connectors

When there’s a damaged connection between your PLC and HMI, the communication port or cable could be problematic. When communication can’t be established between the two, it’s possible that the driver chips for your communication ports are no longer working, which can create problems. Intermittent communication could cause incomplete data transfers and could generate a fault on your PLC and HMI. When your connection can’t be established, it’s time to replace or repair your HMI.

4. Damaged or broken screen

When your HMI is improperly used, such as using items to make selections rather than fingers, it can damage the whole unit. This includes the display, screen overlay, touchscreen, or keypad membrane. All of these things will negatively impact the performance of the HMI unit. A damaged or broken screen will inevitably affect input, and should be replaced. If you’ve got an HMI that’s giving you any of these problems, you don’t need to buy a new one. Qualitrol’s certified technicians are qualified to fix any of these issues. We exclusively work with our certified techs to repair your units and get them back to you. We replace backlights, displays, and touchscreens, and we can repair touchscreen controllers. We can repair or replace almost all internal components and test your HMI to ensure it works perfectly when you get it back. Trust Qualitrol when it’s time to repair your HMI unit.