The testing of BACnet products has advanced tremendously over the past year. After many months, BACnet Testing Laboratories (BTL) is in the final stages of developing the operator workstation portions of its test package, and the BACnet Interest Group for the European Union (BIG-EU) has successfully implemented automated testing of BACnet products.
With the ability to test operator workstation products, the BTL can now test all product types, allowing specifiers to require all BACnet products be BTL tested and listed.
Testing operator workstations
The BTL Working Group (BTL-WG) Test Package is based on tests from the BACnet test standard, in addition to new and corrected tests, product description documentation, and test policies and procedures. The BTL lab and product vendors use it to test their products to ensure they conform to the standard.
The BTL-WG has been developing the test package in stages, slowly increasing the number and complexity of devices that can be tested by the package. Each successive iteration of the BTL test package adds device profiles to the set that the package can test. As revisions are completed, the BTL lab tries out each one on a small number of products before final acceptance of the revised test package.
The current revision of the BTL test package under development, which will add support for operator workstations, has proven to be a long and difficult task.
The BTL recognized in 2005 that the standard definition for a BACnet Operator Workstation (B-OWS) was insufficient. Gathering support from a cross section of vendors and users who participate in the development and maintenance of the BACnet standard, the BTL developed a new set of operator interface device profiles for BACnet. In addition, the BTL developed a profile for an advanced operator workstation (B-AWS) and a profile for a simple operator display device (B-OD). These new definitions were submitted to the ASHRAE BACnet committee for inclusion in the BACnet standard and are contained in addendum 135-2008, which is expected to be published by ASHRAE in summer 2009.
The BTL is currently applying the new test package to five operator workstations. The listings for these devices will be issued by BACnet International after addendum 135-2008 is published.
BACnet test tools
The original plan for testing BACnet products involved the use of automated test tools to improve quality, reduce effort, and allow for test repeatability. The BTL-WG recognized early that if the testing program were to be launched in a reasonable timeframe, the automation of the testing process would have to wait. While automated test tools for BACnet have existed since the mid-1990s, the tools were inadequate for executing the complex tests laid out in the BACnet testing standard. So in 2001, the testing of BACnet products by the BTL was launched using manual test methods.
With the BTL-WG focused on preparing a test package that would cover all device profiles, the development of automated testing took a back seat. In 2005, the BTL started a project to update the open source BACnet test tool VTS 3. Shortly afterward, the BIG-EU also started a project to create an automated test tool. With the initial release of the European test tool in 2007, the BIG-EU started automated testing of building controllers at WSPLab in Germany. The initial run of automated testing of products from 17 companies completed in April 2008.
Having seen the successful application of the European test tool, BACnet International is now considering adopting the same test tool for use in the BTL test lab.
The future of BACnet testing
With the addition of test capabilities for operator workstations, the BTL is now able to test all standard device profiles. But the work is not done; the BTL-WG has to keep the test package up to date as the standard moves forward. Among other additions to the BACnet standard, the recent additions for physical access control and the expected network security extensions for BACnet should provide work for many months to come.
Nielson, currently with Delta Controls, is vice chair of ASHRAE SSPC 135 (also known as the BACnet Committee).
At A Glance
BACnet International is an organization that encourages the successful use of BACnet in building automation and control systems through interoperability testing educational programs and promotional activities. BACnet International complements the work of other BACnet-related groups whose charters limit their commercial activities. Visit www.bacnetinternational.org for more information.