Ever heard of BACNET?


Thread Starter

Scott Jensen

Dear List, At the Automation Fair in Long Beach, CA. today, (12/8), I attended a seminar hosted by very intelligent man who was pushing his, "PLC Control For Building Systems." It all sounded nice until it was mentioned that it is all connected via "BACNET." Although he also mentioned that other standards can be tied in, I am concerned about this "BACNET" protocol. I have never heard of it. Has anyone out there had any history with "BACNET"??? This is important for us, as we are dumping the "Johnson Controls" for part of the plant and possibly going with "Lonworks." I, for one, would love to see building systems run by PLCs, as it would keep all the work, "in house". (Our facility techs can handle PLCs + programming with no problem.) Versus "Lonworks" which would be another vendor supported product like "Johnson Controls." I'm really looking forward to opinions from you all. Scott Jensen [email protected]
Jim Pinto responds :
Yes, it is the "fieldbus" standard being developed primarily for Building Automation (the equivalent of ISA SP-50 for Process Automation).

The fieldbus issue is peculiarly political and fragmented because of the bias of multiple vendors. If you bring in BACNET, you'll complicate the already complicated issue exponentially.

;>) Jim Pinto
Action Instruments
Tel : 619-279-8836 (direct)
email : [email protected]
Action Instruments Webpage : http://www.actionio.com

Phil Walcott

BACnet is a standard communication protocol designed for building automation systems.
It is a networking communication protocol, designed by ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) (ANSI Standard 1995-135), to communicate environmental information over Ethernet, ARCNET and serial networks.
For more info go to BACnet Trade Organization Website http://www.bacnet.org
User group http://www.big-na.org
Check out Cimetrics website at http://www.cimetrics.com


M. Rowe Custom Tech

Ahhh, BACNET it is a protocol that is pushed by an
HVAC standards group called ASHRAE.

ASHRAE has a web site but to get the actual protocol primitives you need to spend some $$$. Many big name HVAC vendors subscribe to the protocol,

CSI, Johnson Controls, Richard Zeta, Andover and many others. The electrical standards are simple RS-422 twisted pair. We broke the proprietary CSI code that rode the set of wires as bacnet.

Marshall R. Rowe
Custom TEchnology

Arnold Dillon

The world of building automation and HVAC control systems exists in a completely different universe from the world of industrial controls. BACNET is the standard put together from ASHRAE for open system digital communication. It is a layered communication interface with a defined
standard available I believe from ASHRAE. They even spent years arguing over the definition of this open system protocol just like the
industrial world has done with Fieldbus.

If you ask some more questions of the building automation people, you will find some that have heard of MODBUS and LonWorks. In my experience, if you talk to the same people about PLC's, Devicenet, Foundation Fieldbus, or Profibus they will just look at you curiously. --Don't get me wrong, many are experienced people that know a lot about energy management and building automation. They just don't have any experience with industrial controls, and instead rely on a different set of standards.

Arnold Dillon
I.C. Thomasson Associates
BACnet, the Building Automation and Control Network, protocol was developed by the American Society of Heating, Refrigeration, and Air-conditioning Engineers and is an ANSI standard. In addition to the canonical 7 layers of a communications protocol, it specifies some HVAC and Life Safety objects and their behavior. The primary benefit of protocols like BACnet and
LonWorks is that they permit the user to get competitive bids on adds and upgrades to his control system.

You can use PLCs to control HVAC equipment--we do it in specific cases. But since we do it for a living, vendors like us, Johnson Controls and
Honeywell, add value by doing more than opening the chilled water valve a little further as the supply air temperature gets a little above its
setpoint. If you're already good at maintaining refridgeration equipment and air handling units, you don't have complex occupancy schedules, you
don't have an opportunity or need to manage peak energy demand, and you have adequate labor resources, you can easily do it yourself.

B.O. Dec. 13, 1999
Robert Old, System Architecture, [email protected]
Siemens Building Technologies, Inc., Landis & Staefa Division
1000 Deerfield Pkwy., Buffalo Grove, IL 60089-4513 USA
Phone: +1(847)215-1050 x5623, Fax: +1(847)419-2401
Dear Mr Scott' I'm from Malaysia, we do face problem with proprietary system, especially the cost & support. is there any possibility to convert from ARCNET to BACNET.
Rockwell Automation has developed a BACNet interface between a Trane chiller system and the ControlLogix/ProcessLogix control system. Post a request for information if this is of interest.
we are looking at implementation of Trane chillers to the contrologix PLC (DeviceNET). could you please provide more info/links.
> Rockwell Automation has developed a BACNet interface between a Trane chiller system and the ControlLogix/ProcessLogix control system. Post a request for information if this is of interest.

[email protected]
please send further information or contact name. We have the exact application for our client.