Modbus crash course

Modbus was a serial protocol that was published in the 1970s as a means of connecting equipment in an industrial process over a common bus. Since Modbus's publication, there have been many evolutions of the protocol and variants. This is largely due to the openness and flexibility of the protocol standard. As this protocol is the most broadly used for connecting industrial equipment, you can imagine there have been many books and papers written on the subject. We are going to focus specifically on Modbus TCP and the various commands and functions that can be used. I strongly recommend reading up on the history and evolution of Modbus, as you will gain a deeper insight into how industry has adapted this protocol to suite their process and specific operational needs. Follow this link to get a brief history of Modbus: https://www.youtube.com/watch?v=OuM28tp5wXc.

Modbus TCP encapsulates Modbus RTU packets inside of a TCP packet, allowing data to be exchanged...