Machines installed in industrial plants use a wide variety of smart devices for control and monitoring, including sensors, instruments, and motor drives. These smart devices are connected to controllers such as PLCs, and often to human machine interfaces (HMIs) through the controllers. These devices can also become part of the industrial Internet of Things (IIoT), and HMIs often make the enabling connections.
There are two main types of HMIs. The first is PC-based—usually an industrial PC when used in machine monitoring and control applications. The second is an embedded platform hosting the HMI software. PC-based HMIs have more features than embedded HMIs. Recent advances have added many capabilities to embedded HMIs, making them similar to PC-based HMIs in many ways, particularly in terms of IIoT functionality.