The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recently announced that Addendum b to ANSI/ASHRAE Standard 135-2004, BACnet-a Data Communication Protocol for Building Automation and Control Networks, was recommended for a second public review.

Addendum b contains new features related to advanced trend logging and specialized alarm handling.

In related news, ASHRAE announced that Addendum a to ANSI/ASHRAE Standard 135.1-2003, Method of Test for Conformance to BACnet, was recommended for public review.

Addendum a defines tests for BACnet features added since the standard was published.