New BACnet Standard Addenda Support Data Representation in XML
BACnet Adds Language Options for Both Computers and Humans
Atlanta, GA, USA. February 09, 2010.
At ASHRAE's 2010 Winter Conference held recently in Orlando [program], the BACnet committee celebrated the approval for final publication of eight addenda to the ANSI/ASHRAE Standard 135, A Data Communication Protocol for Building Automation and Control Networks.
The addenda are expected to be available on ASHRAE.org by the end of February, 2010.
The addenda include a specification for a standard way of representing data in XML that will give BACnet new capabilities for communications between a wide range of applications. The Extensible Markup Language (XML) is a popular technology in the data processing and communications worlds due to its capability to model complex data and its flexibility to be transformed and extended.
"With this new IT-friendly way of representing building data, BACnet will open up new ways to communicate. XML can be used for exchanging files between systems, communicating with the Smart Grid, and expanding enterprise integration with richer Web services," said Dave Robin, chair of the BACnet committee.
The XML syntax is intended to be the core data representation for a variety of uses:
Powerful new Web services that are capable of efficient exchange of complex structured data.
An electronic version of a BACnet PICS document, consumable by workstations and other tools, to describe the capabilities of a device.
An "as built" description of a deployed device, distributed either as a separate file or as a BACnet File object resident in the device itself.
Descriptions of proprietary objects, properties and data types, which may be simple, for basic data sharing purposes, or extremely rich, providing complete descriptions of the meaning and usage of the data in multiple human languages.
An export/import format for tools and workstations publish their knowledge of a complete system of devices and networks.
An XML version of an EPICS, including the complete test database and other test-oriented data.
In addition to the new "computer language" of XML, another addendum has added an important new capability for human languages as well. When the Unicode character set was created many years ago, it was constructed to be universal set of characters to support most of the world's languages together in one stream.
However, its original 2-byte encoding caused trouble with a lot of existing systems that were designed to process only the 1-byte characters common in western languages. The "UTF-8" encoding was created to solve this problem and quickly became a very popular method of conveying international text on the World Wide Web. BACnet has also embraced this standard and uses it in a way that fully takes advantage of its compatibility with the existing and ubiquitous ANSI/ASCII character set.
BACnet has also added support for more data types as well. A set of new "Value" objects rounds out BACnet's ability to represent different data types in a uniform and standard way. Added to the original Analog, Binary and Multi State Value objects, are new Value objects for every primitive datatype that BACnet supports, including support for character strings and large numerics.
ASHRAE, founded in 1894, is an international organization of some 50,000 persons. ASHRAE fulfills its mission of advancing heating, ventilation, air conditioning and refrigeration to serve humanity and promote a sustainable world through research, standards writing, publishing and continuing education.
Details from BACnet.org
XML Addendum Approved for Publication: Arguably one of the most significant addenda in some time, Addendum 135-2008t was approved for publication at the ASHRAE Winter Meeting in Orlando. The addendum specifies a standard way of representing data in XML that will give BACnet new capabilities for communications between a wide range of applications...
Developed under the auspices of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), BACnet is an ASHRAE, ANSI and ISO data communications protocol for building automation and control networks. Tracing its development back to 1987, the BACnet protocol allows heating, ventilating, air-conditioning, lighting, security, fire detection and other building automation and control systems to communicate and exchange information, regardless of service performed. For the latest information, visit: www.bacnet.org.
About BACnet International: BACnet International is an industry association that facilitates the successful use of the BACnet protocol in building automation and control systems through interoperability testing, educational programs, and promotional activities. The BACnet standard was developed by ASHRAE and has been made publicly available so that manufacturers can create interoperable systems of products. BACnet International complements the work of the ASHRAE standards committee and BACnet-related interest groups around the world. BACnet International members include building owners, consulting engineers and facility managers, as well as companies involved in the design, manufacturing installation, commissioning, and maintenance of control equipment that uses BACnet for communication.
The XML Addendum approved in Orlando were to be published in February 2010. Here are references to the earlier review draft materials:
Addendum 135-2008t. Proposed Addendum t to Standard 135-2008, BACnet — A Data Communication Protocol for Building Automation and Control Networks. Third Public Review. September 11, 2009. 55 pages. Copyright © ASHRAE (American Society of Heating, Refrigerating And Air-Conditioning Engineers).
This addendum is now [September 2009] undergoing a 45-day 3rd Public Review from September 11 to October 26, 2009. Link is to a ZIP file containing the draft, 4 supplementary files and a "README" file; see the file listing and archive/cache PDF. A new standard way of representing building data will give BACnet new capabilities for standardized communications between a wide range of applications. A definition for an XML syntax which can be used to represent building data in a consistent, flexible and extensible manner is defined by this addenda in the form of a new annex to the standard.
The Extensible Markup Language (XML) is a popular technology in the data processing and communications worlds due to its ability to model a wide range of data and its ability to be transformed and extended. With this new IT-friendly way of representing building data, BACnet will open up a range of possible new ways to share data. XML can be used for exchanging files between systems, integrating buildings with energy utilities, and expanding enterprise integration with richer Web services. Some of these new applications will be standardized in future addenda to the standard based on the syntax defined here.
XML Data Formats:
Tel: +1 678-516-1207