Andrey Golovin, Executive Director of the BIG–RU Association
Over the past year, the open protocol for building automation BACnet has gained noticeable popularity in the Russian market. It can be heard more and more often in speeches at conferences, and equipment manufacturers that support this protocol are paying increased attention to it in their information and technical literature.
Development companies have appreciated the advantages offered by BACnet. For example, MIRAX GROUP chose BACnet as a protocol for automating the Federation business complex. And this will be practiced in future projects of this company. The Building Automation newsletter regularly publishes materials on BACnet, and I am sure that most of our readers have encountered the term “native” BACnet at least once, i.e. “native” or “real” BACnet. But even in foreign sources there is very little information on this issue, and we decided to figure out what is meant in world practice by native BACnet.
I will immediately note that in most cases two terms appear:
– Native BACnet Device – “native” BACnet device;
– Native BACnet System – “native” BACnet system.
However, both terms are not regulated in the text of the BACnet standard, they began to be used by equipment manufacturers mostly for marketing purposes, to further emphasize the compatibility of their controllers with the BACnet protocol. Trying to understand what is hidden behind these terms, I involuntarily drew an analogy with the concept of «Euro-renovation» — everyone roughly understands what is being discussed, but cannot clearly formulate its standards.
One of the first experts to define the terms Native BACnet Device and Native BACnet System was ASHRAE SSPC-135 committee member David Fisher: «The term Native BACnet was introduced to differentiate between devices that used BACnet as their direct and sole method of communication and those that required gateways to integrate with BACnet systems.»
A Native BACnet Device is any device that uses BACnet as its communications protocol. It can act as a gateway to other automation protocols.
A Native BACnet System is an automation system that consists only of BACnet devices that communicate directly without the use of gateways.
If a building automation system includes 100 controllers and one workstation that is separated from the controllers by a BACnet gateway, and the controllers themselves use a proprietary protocol from the manufacturer, such a system cannot be called native BACnet. If such a gateway is absent, and the controllers communicate using the BACnet protocol, the system can be called a «native/true» BACnet system.
All this is done to make your automation system open for future expansion and to have the ability to replace parts of the equipment or sections of the system with equipment from other BACnet manufacturers (other than the original equipment supplier). Also, for the configuration of the system, you get the freedom to choose the configuration tools from most manufacturers (software). All this gives building owners greater freedom to modify their automation systems in the future.
But, despite all of the above, BACnet does not set any strict requirements — any combination of BACnet devices will work with each other. The standard does allow equipment manufacturers to leave loopholes for themselves to limit the freedom of action of the system user: companies retain proprietary functions and features in the functional set of their devices. On the other hand, some of the companies position this as an advantage for the end user, who receives additional opportunities.
Brad Spencer, another ASHRAE BACnet committee member, defines a native BACnet system as a set of provisions.
– The system must be interoperable (able to work together with equipment from other manufacturers), and its performance with equipment from other native BACnet manufacturers must be no lower than its performance with its own equipment. No licensing fees for communication with equipment from other manufacturers are appropriate in this case.
– The system does not require closed protocols from equipment manufacturers to control the entire system. Other native BACnet workstations can configure and control the operation of any device on the network.
– The system manufacturer promotes BACnet as the language of communication between devices in the automation system and does not impose mandatory training courses on how to operate the automation system on the user.
– The system manufacturer does not overwhelm the user with configuration tools (software) related to its closed system and not having a BACnet interface.
– A Native BACnet system never requires mandatory paid technical support from the supplier, its partners or anyone else.
– And the last sign of a fake BACnet system is when the equipment manufacturer convinces you that its closed system is much better than a system based on the BACnet protocol.
The BACnet standard is an international standard ISO 16484-5, and accordingly it is given priority in most European projects on building automation systems, and especially where there is a government order.
Hans Kranz, a well-known European expert on BACnet, confirms that in Germany, building codes and regulations have been specially developed to allow automation system contractors to more easily obtain a general contract for the entire construction. And, by the way, cases when large companies working in the field of building automation become general contractors are becoming more and more common. And all projects financed from the German federal budget must comply with the German standard «Procedures for drawing up a construction contract», which is related to building automation systems. The opinions of these experts make it possible to understand what exactly equipment manufacturers mean by the term «native» BACnet. But still, we note that the above definitions of the term are not dogma and can be transformed over time. |
