The above block-diagram shows a model of Ethernet automation. The same phenomenon is equally applicable for industrial Ethernet with some amendments. Also the above block diagram is point-point link approach only. The same can be extended to layer-2 network for more sophisticated automation.
What's happening in the block diagram? Touch Screen is placed at user end, say in a control room. Attached with it is a touch screen controller which get the coordinates of touch screen and pass over to Ethernet module. Ethernet module consists of a microcontroller, an Ethernet controller and Ethernet link. Microcontroller on the basis of received coordinates will pass the instructions to Ethernet Controller (ENC-28J60) over SPI. Ethernet controller will then transmit control words / data to its counterpart at the other end. Microcontroller will then drive the triac based or whatever the circuitry maybe accordingly.
More to follow!