FF, HART, Profibus partner to extend DDL specification

Three leading organizations dedicated to control network technology—Fieldbus Foundation, HART Communication Foundation, and Profibus Nutzerorganisation e.V. (PNO)—have started an unprecedented collaborative project to extend the specification for Device Description Language (DDL).

By Staff April 1, 2003

Austin, TX – Three leading organizations dedicated to control network technology-Fieldbus Foundation, HART Communication Foundation, and Profibus Nutzerorganisation e.V. (PNO)-have started an unprecedented collaborative project to extend the specification for Device Description Language (DDL). The organizations call DDL ‘the most important and widely used digital communication descriptive language in the manufacturing and process industries.’

DDL is a text-based language for describing the characteristics of networked field devices. Automation suppliers developing devices based on Fieldbus Foundation, HART and Profibus specifications all use DDL to create Device Description (DD) files that provide information on parameters and other data in a device. DDL is used to develop Device Descriptions that describe parametric information for field devices and convey digital information, such as device status, process data, and configuration parameters.

Proposed extensions to DDL include adding capabilities to describe display characteristics of device parameters, as well as the ability to include algorithmic relationships for complex device parameters, persistent data, and real-time trends. Richard Timoney, FF’s president and ceo, described the DDL extension project as ‘a logical step forward’ to ensure that Device Description technology, as it exists today, continues to meet the needs of suppliers and end-users, while offering extended functionality when required.

‘Three leading technology organizations have listened to the market and are responding with a ground-breaking collaborative effort that will allow DDL specifications to keep pace with industry demands worldwide,’ says Mr. Timoney. ‘Our partnership to extend DDL builds on 12 years of successful use by manufacturers and end-users, and provides the additional assurance that investments in Device Descriptions are safe and sound. We are very pleased to be working with our DDL partners for the benefit of the industry. We share a common technology and a common goal for the future.’

Michael Bryant, executive director Profibus Trade Organization (Scottsdale, AZ), on behalf of PNO, and Ron Helson, executive director, HART Communication Foundation (Austin, TX), both expressed support for the initiative.

Mr. Timoney indicates that Fieldbus Foundation, HART, and Profibus will work jointly to build on established practices, and further extend the DDL specification, while retaining the integrity of the technology used in millions of devices worldwide. ‘Our goal is an industry-standard solution for advanced visualization that maintains the proven integrity of existing DD technology and, most importantly, retains its greatest advantage-operating system and protocol independence,’ he says.

Mr. Timoney adds that, ‘DDL, approved and released by the International Electrotechnical Commission (IEC) as Publicly Available Specification 61804-2, EDDL, will soon become an official international standard for digital plant networks and is already the de facto standard for countless installations globally. Our extensions will build on the IEC specifications and allow implementation of additional functions for complex devices. Those not requiring the capabilities enabled by DDL extensions can continue using the technology as they have in the past, while those needing the additional functions will simply build on what they are currently doing.’

Fieldbus Foundation recently granted a copyright for its DDL specification to the IEC to be used in the development of a worldwide standard for digital communications. Its cooperative effort with the HART and Profibus organizations will focus on defining advanced visualization capabilities for diagnostic and complex calibration procedures, such as valve signatures, sensor calibration curves, persistent data, and certain trends.