TCP/IP is the common transport protocol of the Internet and is actually a set of layered protocols, providing a reliable data transport mechanism between machines. Ethernet has become the de facto standard of corporate enterprise systems, so it comes as no surprise that it has also become the de facto standard for factory networking. Ethernet is not a new technology. It has matured to the point that the cost of implementing this network solution has been dropping to where its cost is commensurate with those of today’s field-buses.
Using Ethernet TCP/IP in the factory allows true integration with the corporate intranet and MES systems that support the factory. To move Modbus into the 21st century, an open Modbus TCP/IP specification was developed in 1999.
Combining a versatile, scaleable, and ubiquitous physical network (Ethernet) with a universal networking standard (TCP/IP) and a vendor-neutral data representation, Modbus gives a truly open, accessible network for exchange of process data. It is simple to implement for any device that supports TCP/IP sockets.