The purpose of this standard is to define data communication services and protocols for computer equipment used for monitoring and control of HVAC&R and other building systems and to define an abstract, object-oriented representation of information communicated between such equipment, thereby facilitating the application and use of digital control technology in buildings.

This standard is under continuous maintenance, which is a process ASHRAE uses to keep standards current through the issuance of addenda, or revisions. Please make sure the standard number and date of issue match your document.

When they are available, these addenda can be downloaded for free at the following page of the ASHRAE Web site:
http://www.ashrae.org/technology/page/132

When they are available, interpretations of the standard, issued by the sponsoring technical committee, also may be downloaded for free at the following address:
http://www.ashrae.org/technology/page/121

Errata lists are issued occasionally and may be downloaded for free at the following address:
http://www.ashrae.org/technology/page/120

Superceded version available
•Looking for an earlier version? This Standard also has a superceded version. You may view it by visiting the Superseded and Withdrawn Standards page.

Units: Dual