Automation World magazine recently had a great primer article on electronic device description language (EDDL) entitled, Device Descriptors Prove Merit. Application manager, Jim Gray, in Emerson’s Rosemount Analytical Liquid division best summarized this important standard by saying:
…the most important thing about electronic device description language (EDDL) is that it makes managing process instrumentation easier.
If you’re unfamiliar with EDDL, here’s a short summary from an earlier news release:
An international standard — IEC 1804-3 — Electronic Device Description Language (EDDL) is a universal interface to diagnostic, real-time and asset management information contained in what is currently a growing installed base of more than 20 million field instruments from a host of manufacturers. With EDDL, a user can calibrate instruments, diagnose problems, provide data for user interface displays, identify process alarms, and obtain information needed for high-level software, such as MES, UI/SCADA, plant historians, asset management and ERP.
Virtually every vendor of process control systems worldwide supports the standard language and the information it describes is available in any HART Communication, Foundation fieldbus, or Profibus based instrument made since 1990.
ModelingAndControl.com‘s Terry Blevins is heading up the ISA-SP104 standards committee to continue to advance the EDDL standard.
I asked Jim for some examples of how this standard makes thing easier for automation engineers, operators, and maintenance technicians. As Jim sees it, the biggest advantage is that the presentation of the diagnostic and other information in smart field devices is separated from the actual data. This allows software applications to present information from a host of different device suppliers in a common, intuitive way.
The best analogy I can think of is RSS where the data resides in XML files on various websites across the internet. RSS Readers like Google Reader, Internet Explorer 7, Firefox, etc. handle the presentation of this information each in their own unique way. As a consumer of RSS feeds, it’s much faster and easier to read the feeds in a common location in a common way with one of these RSS readers.
In the case of Rosemount liquid analytical smart devices like pH, conductivity, and dissolved oxygen transmitters provide EDDL files with their diagnostic, configuration and operating data and make this data available to software packages like AMS Device Manager to present the information. Like the RSS readers, AMS Device Manager presents this data in a standard way including device status, trends, gauges, and advanced device help to name a few. This is true for any suppliers’ devices which support the EDDL standard. Also, other application software which supports the EDDL standard can present this information from Emerson devices which support this standard.
Jim sums it up rather nicely in the article:
The whole idea is to let the user know what is going on with the device and any actions that need to be taken, quickly and clearly, and to make configuration commissioning easier.