Industrial Ethernet… more than just another fieldbus system

Jan. 14, 2008
This whitepaper talks about how today Ethernet-based fieldbus systems perform basic task and so much more

As Ethernet continues to gain momentum in the industrial automation market, it’s changing the way control engineers utilize their fieldbus systems. In the past, fieldbus networks were considered one-dimensional – they performed one task and did it very well – transferring process data between networked devices in a fast and deterministic manner. Usually these devices were on a local segment, isolated from higher-level networks. Nowadays, Ethernet-based fieldbus systems perform this basic task and so much more. With industrial protocols like Modbus/TCP, EtherNet/IP, and PROFInet process data is sent over standard, off-the-shelf Ethernet hardware. No longer are users forced to buy proprietary fieldbus components from a handful of vendors.

One of the core benefits of Ethernet is its ability to handle multiple protocols on the same network medium. A single field device can support many protocols at one time. Therefore, standard Information Technology (IT) protocols like HTTP, SMTP and FTP can be used in conjunction with an industrial protocol. This adds a whole new dimension to fieldbus systems, allowing connectivity options not available with legacy systems.

Hypertext Transfer Protocol (HTTP) was originally designed for transmitting web content across the Internet. It handles the commands and formatting of web data, so web browsers and servers can communicate with each other.

Many Ethernet-based field devices now support HTTP with the use of embedded web servers. It allows users to view and change parameters in a field device using a standard web browser like Internet Explorer. No additional custom software or custom hardware is required. Just enter the device’s IP address in the browser’s address bar and the built-in default page is displayed.