Fieldbus rivals join forces on Ethernet standard

Four of the world`s leading fieldbus organisations - ControlNet International, the Fieldbus Foundation (FF), the Open DeviceNet Vendors Association (ODVA) and Profibus International - are supporting an effort to develop a standard that will allow data to be exchanged between controllers from different suppliers, via Ethernet networks. The work is being co-ordinated by a fifth body, the OPC Foundation.

A working group - including members from Emerson, Rockwell and Siemens - is developing a standard that will be an extension of the existing OPC (OLE for Process Control) data access specification which is used to exchange HMI and controller data.

OPC Foundation president Tom Burke explains that support of the various fieldbus organisations is crucial if the data exchange (DX) specification is to win wide support. "OPC was the obvious choice for Ethernet DX because many automation companies already use OPC standards," he says.

The specification will make it possible "to move data anywhere and at any time, independent of the underlying communication technology," Burke adds.

David Bauman, technology leader for corporate engineering at Proctor & Gamble, points out that until now end-users have had to contend with a variety of communication protocols that do not communicate with each other.

"Automation systems that we have been designing and developing over the last several years require the exchange of data between them, and among systems, using different protocols," Bauman says. "With the OPC Foundation expanding its scope to develop a standard for exchanging data between Ethernet-based communication protocols, end-users will be provided with a simple solution to a real world need."

The DX specification and sample code are due to be released in December. Prototype products based on the new standard are expected to make their public debuts at next April`s Hanover Fair.