Re: Teleconference for Lighting Output object Addendum
- Hi Lighting Applications working group!
We had a teleconference today as part of our plan to move the Lighting
Output addendum to public review. Meeting minutes below. Next
teleconference tentatively scheduled for Friday, April 1, 10am – 12pm.
Thank you, Scott Ziegenfus, for providing the teleconference
BACnet Lighting Applications Working Group
10:00AM – 12:00 PM (CST) on Tuesday, March 15, 2011
1. Opening remarks - working group (10:05AM)
2. Introduction of those present (10:05)
Steve Karg, WattStopper
Rick Leinen, Leviton
René Kälin, Siemens
Scott Ziegenfus, Lutron Electronics
Dave Ritter, Delta Controls
David Fisher, Polarsoft
Dana Peterson, Johnson Controls
Christoph Zeller, Sauter BC
3. Meeting role assignments
time keeper (GotoMeeting)
scribe – Steve Karg
non-agenda item attendant – Steve Karg
4. Discussion and approval of the agenda for this meeting. (10:10)
David Ritter: DHR-019-05 - Changes to BACnet 2008 Addendum I (PPR4).
René Kälin: LAWG-135-2008i-PPR4-Comment-State-0005-20110228.doc
Christof Zellar: "General remarks about current topics (timeout of
commands, fade and ramp times)"
5. Discussion (10:10 – 1.5 hours)
1. Lighting Command converted to Octet-String. Christoph suggests
that this is a hack, and asks what we are trying to solve. Rene
agrees. David Fisher asks why we didn't choose Character String, as it
allows more extensibility. Christoph suggests a method to use default
values for fade, ramp, etc, while only writing the target level.
Christoph concerned about 9 bytes Octet String, which is now much
larger than the largest (4 byte) value a schedule has to hold. Steve
wonders if this is too complex, and how does a Schedule write to a
text sign? Consensus is that is would use an intermediate object.
Rene suggests reducing complexity by moving some things to other
objects, and specifying those objects in conjunction with the Lighting
Output object. Steve proposes that we simplify, and make it simple
like DALI parameters, with Present_Value using the Fade_Time property,
and an enumerated Lighting_Command for up, down, off, step, etc, which
use the Fade_Rate property. Consensus is that this is bad for
concurrent control. Rene to determine whether the priority parameter
used for a commandable Present_Value property can be used for the
Lighting_Command. Discussion of the various lighting command
operations, and what are the value ranges required?
1. Scott to arrange another Webinar on April 1, 2011.
2. Dave Ritter to revise DHR-019-05 based on feedback from this
meeting, and enjoy vacation!
3. Christoph to research the lighting command operation ranges.
4. Rene to research the feasibility of two object properties using the
priority parameter of WriteProperty.
6. Adjournment (12:00pm-CST)