User talk:Funvill/BACnet
For the BACnet article [citation needed]
History
[edit]The development of the BACnet protocol began in June, 1987, in Nashville, Tennessee [1], at the inaugural meeting of the Standard Project Committee (SPC). H. Michael Newman, the first chairman of the committee, presided over the meeting. The first meeting produced a list of desirable attributes of a good protocol, and what the BACnet protocol eventually became: Interoperability, Efficiency, Low Overhead, Highest Common Multiplier, Compatibility with other applications and networks, Layered OSI model Network, Flexibility, Extensibility, Cost Effective, Transmission Reliability, Apply to real-time processes, Maximum Simplicity, Allow priority schemes, Medium access fairness, and Stability under realistic loads.
The Development of BACnet
[edit]However, LON was still proprietary until 1999[2] and not fully developed until 1992; thus, prior to that, the buildings industry felt the need to create a standard. Therefore, in 1987, the BACnet Committee was formed within ASHRAE and began to develop a standard that the industry could adopt. It was not an easy goal to achieve a standard that was technically sound, was able to handle buildings data, was truly non-proprietary, and was easy to implement; however, in June 1995, after years of industry input and reviews, ASHRAE adopted BACnet as a new standard for the industry.
Command Contention
[edit]All BACnet devices are effectively peers. That means that any device can write the value of an object property in another device. All write commands are sent with a priority and the command with the highest priority is used. If anther write command is sent with a lower priority then the value that is currently being use the write command is ignored. [3]