Re: Meeting in Denver, Colorado
- Hi Lighting Applications Working Group!
I have produced a draft of the meeting minutes from our last meeting
at the Adam's Mark Hotel in Denver, Colorado, and converted it to
text so I can post it here. The DOC version LA016.DOC will go into
the SSPC folder for our working group. Let me know about any errors or
BACnet - Lighting Applications Working Group
25 June 2005
Participants - Affiliation
Steve Karg - Lithonia Lighting
Robert Hick - Leviton Lighting
David Fisher - Polarsoft
Craig Spangler - Square D
Steve Treado - NIST
David White - Tour Andover Controls
Rene Quirighetti - Siemens
Randy Shaull - KMC Controls
The meeting was called to order at 1pm. A timekeeper (David White)
and a scribe (Robert Hick) were assigned. Steve Treado was volunteered
to track the non-agenda items. The previous meeting minutes were
reviewed and approved. The meeting agenda was reviewed and approved.
Robert Hick reported on NEMA DALI activity:
Representatives from the NEMA Joint Sections Committee on DALI
attended the COMEX Project Team meeting on DALI in Frankfurt May
11-12, 2005. The NEMA 243 DALI protocol was presented and warmly
received by the PT and NEMA was welcomed as a contributing member. It
was felt that much of the NEMA work would be usable for Part 3 of IEC
62386: Particular requirements for control devices. NEMA is now
working with IEC on section 3-2 ( Arc Power Control: Switching
NEMA 243 version 1.17 is out for comment, a copy was distributed.
Nema has also been negotiating with Freescale Semiconductor to look at
prototyping a stack and simulation of control devices.
LA-WG proposal discussion
DMF030-4/5 WriteGroupMode Service
David Fisher presented this new revision to his original proposal as a
partial solution to the requirement in lighting systems to change a
large number of values quickly.
Primary changes were to the WriteGroupAck service:
Broadcast now changed to Unicast.
A failure code was added if the write could not be completed.
A later discussion suggested that the the Supported_Modes property of
the ControlGroup object be changed to an Array instead of a list.
David made revisions to -4 and produce a -5 version.
A motion was made that this proposal be sent on to SSPC for general
discussion and public review. Motion was passed with no opposing.
DMF032-4/5 WriteGroup Service
David Fisher described his proposal for a solution to the "Speed of
lighting control on the wire" issue, as discussed at previous
The proposal utilizes the concept of "channels", similar to the way
lighting elements are traditionally addressed with protocols such as
DMX-512. Devices may assign (through a mechanism that is a local
matter) a membership in a channel to particular destination properties
or internal values. When a channel is written with a value, those
destinations take on the new value at the same time. A new WriteGroup
service is defined to write a list of channels with respective values
(8 or 16 bit data types).
Questions were raised concerning additional data types. It was
decided that this may be desirable in non-lighting applications and
easily implemented, but may add complication and reduced efficiency.
It was decided to currently leave this as-is and see if there is a
non-lighting interest in changing this.
A request to add "Fade-Time" (transition time) would be of great
benefit to lighting applications. David will revise his proposal
A motion was passed that this proposal be sent on to SSPC for comments
after David makes the revision noted.
A discussion ensued of the requirements in light control for room
combining. The issue may be thought of in two parts:
Overall control and status of whether or not a room is joined with
another in respect to BACnet.
Mechanics of how the lighting control system may utilize BACnet to
perform the functions required when rooms are joined.
David suggested using the "group" parameter of the WriteGroup and
WriteGroupMode services proposed earlier to perform the operations
required when rooms are joined with one another. In this case the
"group" would represent a room. The target device would change group
memberships depending on the status of room joins.
It was decided that the lighting manufacturers represented would bring
examples of room joins scenarios and suggestions on implementing the
scenarios with current proposed BACnet objects and services. Steve,
Robert, and Craig agreed to present this at the next meeting.
It was decided that a future interim meeting would be held with the
other BACnet working groups during the week of Sept. 26 in Norfolk,
Virginia. More details will be posted to the mailing list by Steve
Karg as they become available.