InBuilding - Volume 2, Issue 1 - 7
INTERNET OF THINGS
Today there are tens of millions
of BACnet devices interoperating daily, and more than 1,000
vendors making BACnet products.
These numbers continue to grow
at a breakneck pace. There is also
continuous extension and development of the BACnet standard,
evolving to keep up with new
technologies and shifting needs.
BACnet is truly the internet of
building automation devices.
A key factor is a widespread participation and adoption by actual
makers of devices in the ongoing
refinement and deployment of
products using the standard. That
"legacy" isn't a liability; it's the
core strength that has changed
interoperability from a concept to
a daily reality, worldwide.
What this means is that it's common for buildings to have BAS,
and overwhelmingly those BAS
use BACnet. What it also means
is that there is a treasure trove of
valuable information available
in nearly every building's BAS:
operating information, historical
trending, alarms, etc. And it's easy
to access using an international
standard. But BAS tends to be
building- or facility-centric. That's
great for devices within the facility
that need to interact with each
other, and for systems and management local to that facility.
We can think of the facility and
its buildings and systems - and the
devices that implement automation, monitoring and control - as
one huge container. As long as
the interactions and use of those
devices and their information take
place inside the container, mostly
everything works. Lately, there's
been a lot of interest in how to
best make use of this information
outside of the container. The
boundary that defines the facility has come to be called "the
edge" and the focus of this article.
NEW CLASSES OF APPS
Generally speaking, IoT is the use
of the public internet to facilitate
communication between "things"
across diverse locations. In the
context of buildings and BAS, on
the one hand, we have a facility or
facilities that are self-contained in
the sense that their BAS already
operates and manages them.
What we would like to do is to
allow programs outside of the facility to have access to information,
and possibly even provide high-level goals, to controllers within the
facility. In other words, to allow
external programs to make use of
our treasure of information. There
are many applications for this kind
of access: data mining, maintenance, optimization, planning, etc.
The point of IoT is not to say
what those applications are, but
to enable the use of the internet
to gain access to it. IoT enables
the creation of new classes of
applications that would have been
extremely difficult or impossible.
Why can't we just use BACnet to
do that? Well, you can, but there
are a number of issues. The most
complex is information security.
If the facility exposes its internal BACnet infrastructure to the
public internet, that means that
anyone with sufficient knowledge
could write programs to intrude
into the BAS network and possibly
cause disruption or damage.
There are techniques that
can be used to mitigate this; for
example, using virtual private
networks (VPN). But generally
speaking, these are half-measures.
There are some new additions to
BACnet that are under development that will address this kind of
security, but that's still only a part
of the problem.
In order to use BACnet to do
this kind of interaction, you have
Volume 2, Issue 1 inbuilding-magazine.com 7