About the BACNET open standard protocol

The BACNET standard was developed by ASHRAE in the USA. It is now widely used around the world. Tridium has always been at the forefront of support for the Bacnet standard and has a high level of compliance. The questions and answers below attempt to explain this.

Q. What is Bacnet and how did become a standard?
A. The Bacnet standard was created by a dedicated committee within the ASHRAE origanisation based in the USA. It took many years to develop but has now become a European and ISO world standard. For more information about this you can visit the Bacnet organisation's web iste at www.bacnet.org
Q. How do I know that Tridium complies to the BACNET standard?
A. In order to show compliance with the BACNET standard each manufacturer must complete a PIC statement for each device or system that they supply, which is a standardised way of representing which aspects of the standard are supported. Tridium have two PIC statements; one for our range of controllers and one for the Supervisory software. These PICS are available for download on this page.
In addition to the PIC statements the Bacnet Association has established a testing regime to ensure compliance, called the BTL - Bacnet Testing Laboratory. Tridium's products have been tested and approved so can carry a logo which denotes "BTL certified".
Q. What is a PICS?
A. PICS = Protocol Implementation Conformance Statement
The PICS is a standard way of describing the BACnet functionality of a specific solution in a kind of table format and contains information about BACnet services supported.
BACnet standard objects supported including information
Whether or not BACnet objects can be created and deleted during runtime.
Q. Which object properties are supported and which are read-only?
A. PICS = Protocol Implementation Conformance Statement
The PICS is a standard way of describing the BACnet functionality of a specific solution in a kind of table format and contains information about BACnet services supported and the BACnet standard objects supported, including information about whether or not BACnet objects can be created and deleted during runtime, which object properties are supported and which are read-only
Q. Tridium only have one document for all the controllers. Why is this?
A. All Tridium controllers run the same Niagara AX software, and since it is this that must comply with the BACNET standard only one statement is needed for all.
Q. What types of BACNET communications are there?
A. Various comms mechanisms have been allowed for in the standard. The predominant ones are Bacnet-IP which allows for communications over TCP/IP networks, and Bacnet MSTP which allows for communications over RS485 serial networks.
Siemens have used Bacnet over LON-FTT, and ALC have used Bacnet over Arcnet.