Title: Message
Thanks, Jeremy.
I have to say that it appears that your understanding and
mine are precisely alligned.
tc
From: Jeremy Roberts [mailto:]
Sent: Monday, October 25, 2004 2:04 PM
To: OBIX
XML
Subject: RE: [obix-xml] RE: [obix-req] Firewall traversal use
cases
Charles,
I'm
sorry for adding my 2¢ so late to your comments. Travel is my pathetic
excuse.
oBIX
should be concerned with levels 2 through 4, as you have described them,
below. The reason for acting at
level 2 is because at that level we have a transformation from the controls
network to the IT-interfacing specification (oBIX). Level 1 is handled entirely by the
controls network of choice (be that BACnet, LonWorks, or any other installed
device network). To propose oBIX at
the buildings-control level would mean modifying the massive installed base of
controllers, actuators, and sensors that have benefited from such existing
controls network. Economics aside,
for this group of people in oBIX to redefine installation methods, configuration
methods, and general IT-like maintenance of the devices at the controls level
would be far to daunting a task, and would be a reinvention of the wheel (with
arguably something less robust that presently exists).
The
controls networks can reach as far as level 3 and 4 as well - and presently
do. However, in a campus containing
level-1 controls networks comprising more than one protocol, there is no
interoperability at levels 2 through 4 (or of course at level 1). It is this case/reason that oBIX is
needed: In a homogeneous control
network, there is no need for oBIX.
Level-two
interfacing is the heart from which oBIX stems: It allows for a BACnet system to feed
information to a black box, and a LonWorks system to feed information to a
different black box, where those two boxes then convert the information to an
IT-palatable, web-services -based set of standardized "rules" (oBIX) to allow
levels 3 and 4 to assimilate those data into their appropriate systems. Icing on the cake is being able to share
those same data between systems that play at levels 3 and 4 - with 4 being the
primary field of high-level sharing.
Unless I
have missed, or misinterpreted, something (which is always possible), this was
and is the goal.
Best
Regards,
AUTOTEXTLIST \s "E-mail
Signature" Jeremy
ROBERTS,
Technical Director
LONMARK
International - http://www.lonmark.org/
Main
Technical Office - mailto:
PO
Box 268, Jamison PA 18929-0268, USA
Telephone:
+1-215-918-1026, Fax: +1-215-918-1027
________________________________________________________________
-----Original
Message-----
From: Watson, Charles D
[mailto:]
Sent: Monday, September 27, 2004 9:01
AM
To:
Subject: RE: [obix-req] Firewall traversal
use cases
This question depends
on where OBIX fits in the system scheme. If my understanding of the OBIX
scope from the last conference call is correct, we don't need to concern
ourselves with firewall traversal.
However, I don't agree
with the limited OBIX scope that was suggested on the conference call. I believe
we need to go lower in the system which means we may require communication
between remotely located devices communicating over the internet traversing
firewalls. We don't need to layout the exact method of communication at this
time because this standard has not even been 100% defined by the IT (MS and
others) powers concerned. But I believe we can layout some high-end standards
for data formats and minimum data content so that hardware and system
manufactures have something to guide them.
Let me explain for the
people who were not on the latest phone conference and to be clear I understood
what was discussed on the phone. We had a short discussion pertaining to the
different levels in a system and where OBIX should spend its time and
resources. The levels assigned here are my words, not what was discussed
on the phone but I believe the group needs to formally define these
levels.
Level
1: Communicating hardware devices: electrical meters, security and fire
alarm system components, HVAC components, etc.
Level 2: The
communicating gateway: This device normally communicates with the level 1
devices, packages/transforms the data, and communicates it up to a central data
logging system.
Level 3: Central
logging and alarming system: Collects, monitors, alarms, and logs the data
from the Level 2 systems and occasionally communicates with high-end level one
systems directly. This level is usually the HMI or visual process control level
of the system. The direct users of this system are still technical users who
have some understanding of the underlying hardware systems. These users are
usually concerned with how well and efficiently the system (HVAC, electrical,
etc.) operates from a technical perspective. They communicate with the system in
real time, know what is happening right now through direct interaction with the
system and the lower levels of the system.
Level 4: Enterprise
systems. This is where the accountants, building managers, and general
management interact with the system. These users usually have little
understanding of the lower level components and usually are concerned only with
how much it costs, not how it technically works. At this level, the
communication is usually via reports or some real time viewer
(dashboards) but not direct interaction.
Some of these levels
are combined in one device or system but a single device rarely constitutes the
entire system. So the format of communications between levels needs to be
defined. This is where OBIX needs to define the XML standards/guidelines
in my opinion. During the phone call, it was stated that OBIX should only be
concerned with the transfer of data at the higher end of this scheme:
between levels 3 and 4. I don't agree.
Although we don't want
to meticulously define the data interchange format between hardware devices
(level 1) and the level 2 & 3 systems, we do want to define some
standard of data content and some idea of its format. Otherwise, we will get to
the level 3 systems and the data may require complex transformation to get the
data into an acceptable format for the level 4 systems. There could even be data pieces missing.
If we start laying some data transfer standards/formats lower in the system, the
data will already be practically in an acceptable format for the next level with
minimal transformation
In summary, if you want
high-quality data at the top, you need to collect high-quality,
comprehensive data at the bottom. This means the rights pieces of data in
the right format at the right time. The exact method of data transfer can
be determined later.
Thanks,
Charles Watson (Chuck)
CEM CMVP
tel: 724-779-5937
http://www.eatonelectrical.com
-----Original
Message-----
From: Doug Ransom
[mailto:]
Sent: Friday, September 24, 2004 6:38
PM
To:
Subject: [obix-req] Firewall traversal use
cases
We
have not had any use cases involving firewall traversal. Is this an
issue.
Doug
Ransom
Energy Analytics
Domain Expert
Power
Measurement
2195 Keating Cross
Road
Saanichton, BC,
Canada V8M 2A5
Tel: (250)
652-7100 ext. 7558
Fax: (250) 652-0411
E-Mail:
mailto:
Website:
http://www.pwrm.com
ION® smart energy
everywhere(tm)
