Industrial Controls — User Inputs and Outputs
HMIs are industrial UIs that are designed to talk to hardware. As such they offer us ways of entering data into a PLC and displaying data that was received from the PLC. HMI development packages can make this process very simple. In short, most HMI development packages will fall into a low-code or no-code category. Even if you use an advanced SCADA package, you’ll find that the actual coding will be minimal. The only time you’ll write copious amounts of code for your HMI is when you use a traditional programming language such as C# or Java.
With that in mind, most HMI development packages, such as the one in CODESYS, will give you a wide variety of input and output controls to choose from. Also, since there is no coding with the CODESYS HMI development tool, attaching the controls to the PLC code is very straightforward.
Now, with that being said, HMIs are very important pieces of software that can make or break...