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Product category: Engineering Education, Resources and Standards
News Release from: Fieldbus Foundation
Edited by the Engineeringtalk Editorial Team on 21 November 2003

Fieldbus organisations aim for
interoperability

Three leading organisations dedicated to control network technology have completed the initial phase of development for key extensions to Electronic Device Descriptions defined in IEC61804-2.

In an unprecedented collaborative effort, three leading organisations dedicated to control network technology, the Fieldbus Foundation (FF), Hart Communication Foundation (HCF) and Profibus Nutzerorganisation (PNO), have completed the initial phase of development for key extensions to Electronic Device Descriptions (EDD) defined in the IEC61804-2 standard IEC61804-2 is the only international standard for device descriptions

Within Foundation fieldbus, an EDD is referred to as a Device Description (DD).

The EDD enhancements, which were defined by a working group that included participants from ABB, Emerson Process Management, Endresss+Hauser, FlowServe, Honeywell, Siemens, Yokogawa and FF and HCF staff, are included in a draft specification that all three control industry organisations will validate in a lab environment and integrate within their respective technologies.

Building on the current IEC61804-2 standard, the working group extended EDD to provide graphical visualisation of data, improved data organisation, and persistent data storage Fieldbus Foundation Director of Technology Development Dave Glanzer complimented the cooperative team on its work.

"The team did a fantastic job of defining the extensions and delivering a common specification that all three organisations can support", said Glanzer.

"The good news for manufacturers is that those requiring the extensions will have the ability to use them, and those who do not require the extensions will continue to develop EDDs as they do today".

"The three technology organisations have listened to the market and responded with a successful collaborative effort extending the EDD specification to meet industry needs.

Our partnership extends EDD and builds on 12 years of successful usage by manufacturers and end users, providing additional assurance that investments in device descriptions are safe and sound.

We share a common technology and a common goal for the future".

Glanzer added: "We achieved our initial goal of development of a common draft specification for advanced visualisation that maintains the proven integrity of EDD technology, and most importantly, retains its greatest advantage: operating system and protocol independence.

EDD, approved by the IEC as Draft International Standard 61804-2, is already the de facto standard for countless installations around the globe.

Our extensions have built on the IEC standard and allow for implementation of additional functionality for complex devices.

The three organisations will now move forward independently with validating the draft spec to insure compliance and usability of the extensions through lab implementations of each of the technologies".

With over 15 million EDD-based Foundation fieldbus, Hart and Profibus devices installed worldwide, EDD is the most important and widely used descriptive language in the automation industry.

EDD provides a structured text language that is operating system and hardware platform independent.

Automation device suppliers use EDD to provide information on parameters and other data in a device.

The host reads the EDD to integrate, configure, setup, operate, diagnose and maintain the automation devices.

The EDD extensions are built upon the existing IEC standard.

This approach has many benefits.

For example, device developers do not need to deal with the burden of designing and programming a graphic display system that must run under a variety of platforms and environments, from large human-machine interfaces (HMIs) to the small handheld.

Instead, they can use common graphic display capabilities provided by commands in the EDD.

As many host systems today already implement EDD-based graphic display systems, devices using the extended EDD have a common look and feel with existing devices.

This permits uniform integration, configuration/setup, operation and diagnostics/maintenance multivendor environment.

EDD also provides operating system and platform independence, which eliminates the need for special "plug-in" executable code that is costly to develop and can jeopardise the hostūs control over the human interface and operating environment.

In addition, extended EDDs follow proven test and registration procedures, including the same strict revision control policies as todayūs EDDs, thus eliminating problems in the field.

The EDD extensions enable device developers to logically organise the large number of parameters in complex devices.

They also allow the inclusion of images (eg jpg files) to aid the user in device configuration.

With extensions to any standard, it is important to maintain compatibility with existing technology.

The implementation of EDD extensions are designed to be completely compatible with the existing technology.

For field device developers, there is no need to learn a new, operating system-dependent programming language, since EDD is not tied to any specific platform.

For simple devices, developers can continue to write EDD like they do today using the existing or extended DD Tokenizer tool.

For more complex devices, developers can build upon their existing EDDs (cut/paste) to create an advanced EDD using the extended DD Tokenizer tool.

On the host side, the host supplier simply integrates the updated DD Services which can read existing and extended EDDs.

The success of the collaborative effort to extend the EDD standard serves as a model for future work.

Equipment suppliers and end users greatly benefit from building on open, international standards, and from use of common technology.

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