Ethernet,an established universal standard for office networking, is now moving its way down to the plant floor.

While proprietary plant networks often run at speeds only up to 2Mbps, the imminent Gigabit Ethernet at 1000Mbps promises to ensure Ethernet’s place at the heart of factory networks. As factory automation processes are driving up bandwidth requirements, fieldbus networks, the networks designed for factory automation, are failing to meet bandwidth requirements. Only Ethernet can handle the huge increase in data traffic we are already beginning to see in 21st century manufacturing. Ethernet as a control network is cheap, standardised, open, faster and available worldwide from multiple suppliers. With the PC industry behind it, Ethernet in industry will be able to compete on price as well as on performance. The high volume of Ethernet shipments drives economies of scale and its large customer base has brought down prices for components. New quality of service assurances over the once doubted robustness of Ethernet and the move to switched Ethernet technology mean that at last it is a viable alternative on the factory floor. Cisco and GE Industrial Systems launched last June a joint-venture, GE Cisco Industrial Networks, designed to extend the reach of Ethernet onto the factory floor. The venture is aiming to achieve US$100 million in annual turnover by 2005. At the moment, proprietary fieldbus systems remain the most common network communications technologies on the factory floor. They join together equipment such as programmable logic controllers (PLCs) and distributed control systems (DCS). While many people are predicting the imminent disappearance of the 60 or so proprietary bus systems, this is unlikely. Since major vendors are not likely to ask customers to rip out their proprietary system, there could be life in the buses for a while. A more likely interim solution will be that pursued by Siemens, the maker of the Profibus system, which is introducing gateway devices between buses and Ethernet. The Automation and Network Solutions of Hirchsmann are also popular Ethernet-based products for the factory. Ethernet now promises to be able to link factory control systems more easily to enterprise systems such as ERP and CRM, and then to the front end – creating a genuine e-business. Integrating the plant-floor system via Ethernet should help encourage a build-to-order, just-in-time efficiency culture throughout the company, allowing low inventories and quick-order execution, on the basis of a real-time flow of information. plant automation industry is now looking to create a universal Ethernet/IP industrial application layer. In this case, ‘IP’ stands for Industrial Protocol. This layer will ensure the interoperability of their products, so that users will be able to link to all Ethernet/IP-enabled devices. Ethernet/IP is supported by three standards organisations: ControlNet International (CI), the Industrial Ethernet Association (IEA) and the Open DeviceNet Vendor Association (ODVA).