In a SCADA system, there are a lot of different parts working together: sensors, PLCs, RTUs, various communication technologies, and more. Most of these are on the machine end of things, monitoring, collecting data, transferring information, and controlling various devices. Of course, you need to have a user-friendly way to monitor and manage all of these moving parts and their functions. The answer to this SCADA problem is the HMI, or Human Machine Interface.
What is an HMI?
An HMI is essentially something that allows a human user to interact with or control a machine. This can be something like a control panel or a series of buttons to push. However, when it comes to a SCADA system, you�re probably going to be interacting with a GUI, or a �graphical user interface,� which will be displayed on the monitor. This kind of HMI doesn�t just let you control what�s going on. It actually provides visuals so that you can easily monitor the various devices and locations associated with your SCADA system.
Today, you will often see HMI software packages designed particularly for SCADA systems. Since you want to make sure you get the most out of these setups, here are a few things you should look for:
- A detailed, easy-to-understand informational display, so you can have a good idea of what is going on in your system, and how you can manage it.
- Support for multiple protocols. If one of your vendors drops support, goes out of business, or stops carrying your favorite products, your system won�t suddenly become obsolete. On that note, you�ll also want a system that can grow with you for about ten or fifteen years.
- Filters for �nuisance alarms,� or nonessential alarms. This is helpful so that your staff 1) doesn�t become desensitized to alarms, and 2) knows that when an alarm is going off, it�s for something that�s actually important.
- A solid backup system. This is in place so that you have backups if your main �master� fails.
Since your HMI is how you, the user, will most often be interacting with your SCADA system, the most important thing is to find one that best suits the needs of your particular organization.
Want more information about HMIs and SCADA systems? Check here for HMI/SCADA training tips.