Originally focused on discrete automation applications, industrial Ethernet (IE) switches are increasingly employed in applications outside this traditional base. Infrastructure applications ranging from smart grid (particularly electrical substation automation), to intelligent rail, highway, and other transportation projects increasingly rely on industrial Ethernet. Industrial Ethernet has also made significant inroads in process automation, where it is already the control backbone network of choice and is now making its way into the device level.
This expanded application base and its associated functional and standards requirements, plus continued evolution in both COTS and application-specific standards and technology, result in an ever-expanding variety of switch configurations beyond the traditional five- to eight-port DIN rail industrial Fast Ethernet device. Read more about the subject here