Monday, August 31, 2009

Sustainable Building Standards

The good folks at the BIG-EU office (MarDirect) decided that I should write the editorial for the upcoming BACnet Europe Journal, issue #11. The focus of this issue was right down my alley so I agreed and put it on my ToDo list (which is part of my Weekly Report to my supervisors --that's plural, one in Germany and one in Redmond-- so it doesn't get forgotten).

Since then I'd kept looking at it but there was always something more immediate. Until today, when I realized the deadline is tomorrow. A bit of a scramble but I got it together and e-mailed off to them.

But in the process I finally looked into something I'd meant for some time to look into. As a LEED AP I'm certainly quite aware of the US Green Building Council and know that LEED is recognized and sometimes used elsewhere in the world, but I'd never looked up the World Green Building Council before. What a surprise, to see the national GBCs already established (I knew of a couple, but not the rest), and those being organized. Still, there are also some systems not represented, such as the Chinese "3 Star."

"Standards must be good," goes the joke, "otherwise why would we have so many of them?"

I suspect all of these groups have something to share with the rest: particulars of dealing with specific climates, experiences in what's been tried and succeeded (or failed) -- why not a single international standard for sustainable buildings?

Sunday, August 30, 2009

Sailing to Strasbourg

...might be easier than flying! The annual membership meeting of the BACnet Interest Group - Europe (BIG-EU) will be there next month and I will be attending. But booking flights through the approved travel site is proving to be a headache: I have a choice right now of having only 1-1/2 hours in Lyon to clear immigration and customs and catch my flight to SXB, or barely making a return connection home by flying into Orly (south of Paris) and out of CDG (north of same).

But this trip will also be a birthday present to my wife, a native Francophone & Anglophone but who also speaks the native languages of most BIG-EU members including German, Dutch, and Italian. She wants to see Strasbourg again, and I'll get to introduce her to my BIG-EU colleagues.

It's only a shame that an old friend and former colleague from my ISO/TC205/WG3 committee, Dr. Hans Kranz, who lives not so very far away, will himself be away at the time.

Friday, August 28, 2009

State machines - standard to code

Under the idea that a picture, or maybe three, is worth a thousand words, I thought I would provide an example of why the state machines need not be all that large. (And I hope Blogspot will leave them large enough to read.) Here is a snippet of the MS/TP Master Node State Machine from BACnet-2008:

Now for my PIC12 project I first wrote the code in C and tested that.

Then, because the PIC12 was a small processor with a number of limitations including a very small (4 level?) stack, I hand-coded from C into assembly:

Thursday, August 27, 2009

State machines

Way too often I see new implementers trying to take shortcuts when implementing the various BACnet state machines (Clause 5 Application Layer, Clause 9 MS/TP, and especially Clause 10 PTP). They attempt to infer the intent of the machine and implement their inference instead.

Such attempts frequently, if not always, end in failure. It's not that hard to implement straight from the standard. Perhaps it would help to have an informative annex that provides pseudo-code or actual code, such as was done for the CRC calculations in Annex G.

I wonder if the committee would entertain, or be merely entertained by, such examples written in FORTRAN IV -- or IBM 360 assembly?

Wednesday, August 26, 2009


I would really like to abolish slaves -- MS/TP slaves. I don't like them. (Sorry if the following gets a bit technical.)

It seems to me that when BACnet was being drafted there were two schools of thought: "static binding," in which a client device was configured with a server's network number and MAC address, and "dynamic binding" in which the client was configured with server's "instance number"; the client would then locate the server using a broadcast: "Car 54, where are you?" (Yes Richard, this reference may date me but I never saw the show.) The "I-Am (here)" broadcast has the responding server's network address; then the two can talk directly. Both schools are embodied in the standard.

Alerton chose dynamic binding early on -- as soon as we had some prototype MS/TP slave devices (VLCs) running we learned how annoying static binding would be for our users, and the VLCs quickly became MS/TP masters instead, just so they could broadcast "I-Am" in response to "Who-Is". Much of the rest of the market has chosen dynamic binding also. Among the benefits: you can move a server device from one network to another and the clients will find it automatically -- no reprogramming necessary. The same is true if you swap out an Ethernet card (or device).

The problem is that MS/TP slaves are are part of the standard. This may have made sense back around 1990, when microcontroller ICs had very limited program memory, but it doesn't today. Back in 2003 I wanted to see "how low one could go" in BACnet and developed a small BACnet device using a PIC12 (under US$2, maybe closer to $1) - 2k instructions, 96 registers of storage, no hardware UART, 8 pins. In 2k instructions I got a software UART, an MS/TP Master Node (under 400 instructions), Who-Is & ReadProperty & WriteProperty execution, I-Am initiation, a Device object and one or two Analog or Binary I/O objects.

And this is a problem because new BACnet developers always seem to want to make MS/TP slaves, not considering the end users. Sure, the BACnet committee has worked to "free the slaves" and added methods for routers to discover MS/TP slaves and issue proxy I-Ams for them. The problem is that legacy systems do not have this capability; there their slaves are not "free" and new developers might not be aware of this.

The committee left an out for MS/TP slaves in the recently-revised Device Profiles (in Addendum l to BACnet-2008, which added more support for dynamic binding). But as long as there is an "out" new developers will try to take it.

In the long term it will probably make little difference as proxy-capable routers become more prevalent; ironically during the same time that microcontroller technology is reducing the cost-effectiveness of the MS/TP slave device to zero -- for its manufacturer, if not its user.

But for today, as I advised just this week to a group of developers new to BACnet, it's better to develop MS/TP master devices. The cost is small, the avoided headaches large.

My humble opinion.

Tuesday, August 25, 2009

"BTL Manager Job Position Available"

So says the BACnet International website today. Yes, Lori Tribble has tendered her resignation after years of managing the BTL Lab and managing to keep the unruly crew of engineers comprising the BTL Working Group in line. She says she'll still be involved in the BACnet world, though.

So now we have to find a new BTL Lab Manager.

BACnet Alarming Summit

OS-WG convener Bernhard Isler issued a broadcast e-mail this morning (his time, in Switzerland, as well as mine) re-announcing Alarming Summit 2, to be held three days in advance of the week-long fall meeting of the BACnet committee this November in Atlanta. Apparently he had announced it earlier this summer but received few responses regarding attendance -- I for one do not recall seeing the message.

8 days straight of technical standards meetings is grueling, even for long-time BACneteers. I know I'll be completely fogged by the time I head home.

But hopefully this will be the last Alarming Summit. Last year we looked at extending BACnet's alarm capabilities, came up with a number of action items, and new proposals been submitted for review and discussion.

(Thanks to David Fisher for last year's graphic.)

Monday, August 24, 2009

Slow time... for now

Late August is a pretty slow time in the BACnet world; a lot of folks go on vacation, the BACNET-L e-mail list becomes pretty quiet, the BACnet committee chair starts catching up on the backlog of his To-Do list... but it won't be slow for long.

In just a month from today the BACnet International/Facility Decisions conference in Las Vegas NV will have ended, I'll be packing for a trip to Strasbourg, France for BIG-EU meeting, with maybe a week home before the BTL-WG meeting and BACnet International Plugfest in Atlanta GA, followed almost immediately by the Alerton International Sales Conference in Santa Fe NM concurrent with the BACnet Forum Beijing, followed by 2 more weeks at home before returning to Atlanta for the week-long fall meeting of the BACnet committee, possibly preceded by the second "Alarm Summit" of BACnet experts, all taking place in just a month and a half.

I feel tired already.

Thursday, August 20, 2009

Change in plans

Sadly, I will not be going to the BACnet Forum Beijing after all. It coincides with the annual Alerton Sales Conference and Alerton decided it was very important for me to be at the conference. The conference starts the Sunday after the BACnet International plugfest; I might get a day at home between the trips. I will be sorry to miss Beijing, and to see how it's changed since I was there in 2000, but at least I'll get to see some old friends among our Regional Sales Managers and dealers.

Too much material!

-- way too much! I was planning to take part of the talk from the ASHRAE Region 5 CRC and turn it into a new talk, "Greening to Standards" (what ASHRAE and USGBC standards and guidelines say about using your BAS to save energy) but... trimmed down it's still 77 slides and I have even more material to go into it. Way too much for a 50-minute talk. A new approach to this is clearly indicated.

Tuesday, August 18, 2009

An anniversary missed

It had to have been all the other things going on, including a couple of short BACnet videos to be taped this afternoon that I completely forgot an anniversary yesterday.

It was 10:30 AM Thursday, August 17th 1995, when Alerton company owner Tony Fassbind called a company meeting in the lunchroom. I went of course, like everyone else.

In this meeting he talked of opportunities, and how Alerton came into existence when its founders took the idea of a microprocessor-based building automation system (BAS) to their employer and were rejected. He said that this industry, unlike most, had a second wave about to roll through it and that wave was "BACnet" -- a *standard* (by ASHRAE) communications protocol for building automation. And that there was an opportunity for Alerton to take the lead in the market by offering BACnet products top to bottom, from the operator workstation to the lowliest controller.

Then he held up a copy of the BACnet standard, said "This is our Bible," and to my surprise he put it in my hands and said, "You are now our expert -- learn it!"

I did; and 14 years (plus one day) and two acquisitions later, I am still here.

Somehow I missed the anniversary... but unlike a forgotten wedding anniversary, I skate on this one.

Friday, August 14, 2009

The first BACnet workstation listings

The long grueling ordeal is finally over, the press release submitted, and first five BACnet workstation listings are now published on the BACnet Testing Labs (BTL) website.

I had to dig back into my files to ascertain correctly when this all began and yes, it was almost two years ago that we submitted Envision for BACtalk (EBT), Alerton's BACnet workstation, to be one of the candidates for the "first round" of workstation testing by the BTL. (In these "first rounds" we are not only testing devices, we are also testing the testing procedures and the candidate devices are all tested concurrently, but nobody other than the BTL officially knows who submitted devices -- this helps protect those who withdraw for whatever reason, which has happened in "first round" testing.)

This was of course preceded by years of effort to identify, define and write the tests that would be applied, but it was complicated by moving targets -- not only were the requirements changing but in the process we realized that the "one size fits all" requirements of the B-OWS (BACnet Operator Workstation) device profile in the BACnet standard didn't really match up well with the variety of workstations on the market. So we had to define new profiles, eventually adding the Advanced Workstation (B-AWS) and Operator Display (B-OD) profiles to the B-OWS, which appeared in Addendum l. (Download it here.)

Just to make it even more grueling, not only the targets were changing but our workstation was too. EBT was close to matching the proposed B-AWS profile, but not completely, so we had a long series of meetings to determine the new capabilities needed, how they would be added, and how work was progressing on their development. And all the while our target, the proposed Addendum l, was itself changing.

When its third public review ended this spring, with the testing also nearly complete, we could only sit and hold our breath. Even after the testing ended, we would not really be done until ASHRAE published the addendum because changes could still creep in, changes that could require changes in our software.

But we got there. Addendum l was published, we were able to submit our listing applications and on Thursday the listings for EBT and four other workstations went live.

And finally, after almost two years, I definitively learned who were the other participants. Congratulations to you all -- and to our hard-working EBT team!

Thursday, August 13, 2009

Reading Material

Since I'm speaking at the BACnet Forum Beijing in a couple of months, I'm beginning to keep more of an eye out for material related to the market in China. This morning a Frost&Sullivan webcast grabbed my attention when it mentioned the "3 Star" green building evaluation system in China. Okay, I've been too narrowly focused on North America and Europe (and if I ever get to Hyderabad, India, I'm promised a tour of a LEED Gold building).

Though it seemed unlikely the 3 Star system would be available in English, I figured there would at least be something about it on the web -- and there was! -- once I came up with the right search terms to navigate past all the "3 star" hotel websites on the 'net. I didn't have to call on my Chinese colleagues after all.

The China Green Buildings blog apparently has links to a copy in English. For technical reasons I have to wait until later to download, but it should be interesting reading. Thank you, Mr. Geoffrey Lewis.

Wednesday, August 12, 2009

Plugfest 2009

Although there isn't an official announcement on BACnet International's website yet, I'm told that this year's North American Interoperability Workshop will be held in Atlanta on October 13-15. (Yes, there is another, held every other year in Europe and sponsored by the BACnet Interest Group - Europe; last April it was in Helsinki.)

I always recommend that BACnet developers attend these events. It helps them to see how others have gone about their BACnet implementations -- and sometimes why the BTL Working Group imposes requirements over and above the standard. It's conducted in a informal and congenial environment.

Last year there were almost a hundred attendees from 29 companies from all around the world. I wonder if this year will top that?

Update 8/13: The official announcement just went up here. Hmmm... Sheraton Gateway Atlanta Airport? I know that hotel -- stayed there one night last fall after week of the BACnet committee meetings ended and before I flew to Dallas for a conference. The shuttle may get a bit busy...

Oh, about "BACnet Bill"

I forgot to note earlier the origin of the moniker "BACnet Bill." No, it didn't spring from a marketeer's feverish brain. It was my idea, and it was supposed to be a secret.

Back in '96 when Alerton was developing the first top-to-bottom line of BACnet products, each developer had a small BACnet setup comprised of our workstation, a building controller/router and several small VLC controllers on MS/TP. We engaged in rather a bit of kidding in our 4-man "pods"; one developer became known as "Al Fagiq" (alpha geek), for example. And it was in a similar spirit I changed the device name on one of my devices to "BACnet Bill" while doing some testing, knowing it would would never be seen.

And for a while it wasn't. Until we sent some devices to Steve Bushby at NIST for testing per the BACnet Interoperability Testing Consortium agreement in effect at the time. I don't remember the particulars, but he was seeing something unexpected and called me. It became necessary to replicate his setup so I did, and then took a sniffer trace of my network's activity and sent it to him.

We started going through the trace, packet by packet, and I'll never forget when he read out, "And here the workstation is requesting the Object_Name from another device, here is the ACK, and what's this...? 'BACnet Bill'?"


Tuesday, August 11, 2009

Dotting the 't's, crossing the 'i's

Sometimes things just fall through the cracks. For all the intense scrutiny paid to so many elements of "Addendum q" (BACnet/ZigBee wireless), nobody noticed that it didn't get added to Annex A's "Data Link Layer Options." Or maybe it was because of the intense scrutiny -- on other things.

Sunday, August 9, 2009

Explaining PICS and BIBBs

A few days I was in a meeting to discuss new procedures for developing and maintaining PICS (Protocol Implementation Conformance Statement) statements for BACnet devices. Once upon a time, when Alerton was a small company with a single small development team, it was easy to produce and update these as needed. This is no longer the case, and often the applications and underlying concepts have to be explained over and over -- as I did in that meeting. The usual warning is when I hear "PICS and BIBBs" used as if they are separate documents.

I vaguely recall having given a "Brown Bag" (in-house lunchtime teaching session) on the topic many years ago, so I went looking for the powerpoint. Instead I found my speaking notes dated 2/01/2002 -- over 7-1/2 years ago! Of course, some of those folks have moved on and many folks have joined since then, including most of those in this meeting.

So I took a couple of BACnet class powerpoints, excised the specification and testing sections and produced a PDF to explain this to our team.

I wonder how many other BACneteers have had to go through the same exercise?

Friday, August 7, 2009

What's this "BAC Cave" anyway?

There is a sign in the hallway outside my office identifying the office as "The BAC Cave"; the graphic is displayed on the upper right corner of the blog. It's a bit of a story how that name came to be.

Not too long ago I was in one of the larger one-man office spaces upstairs at Alerton. It had a northern view, which I appreciated because it never got direct sun. All was well.

Until I started reading LEED standards. That's when I stubbed a toe, inadvertently setting off on a new journey.

I began to realize I didn't really like the overhead (indirect) fluorescent lighting, so why not save a little energy and utilize the conveniently-provided individually-controlled light switch ("Controllability of Systems, Lighting," the credit is called in LEED-CI/-EB/-NC/-Schools, and earns one point towards a LEED rating), and use lower-energy task lighting instead? A brief adjustment, then it was good.

Until winter's glaring white skies arrived. I was up often to adjust the blinds.

In the meantime others had questioned my dimmer office, calling it a cave; I just said I liked it that way and it used less energy. After a while, I noticed someone else had begun to do the same.

But Alerton was growing, the larger offices were being doubled-up, and eventually "The Cave" was targeted for two new hires. There were few available spaces; I could move down to "the pods," double-up in a larger office, or take a smaller single office. (My job puts me outside the normal organizational structure of R&D, Sales, Marketing, etc., so I could relocate anywhere in the building.)

I chose an office at the end of this hallway around the corner (this is R&D-land, believe it or not, engineers occupy those offices!). "'The Cave' would now be at the back," somebody noted. Since I was working in the arena of Building Automation Controls, it naturally became "The BAC Cave."

Wednesday, August 5, 2009

Setting Out

"A journey of a thousand miles begins with a stubbed toe. Ouch!" That's not what Lao-Tzu actually wrote but often enough that's how it seems to go. That or "The Item Left Behind." There's not much for me to leave behind on a blog* so it looks like a another toe is about to be stubbed. Ouch!!

What's the blog about? Well, building automation and related stuff I encounter in my work.** Stuff like BACnet, LEED, ARRA, ASHRAE committees, ISO committees, other committees, BIG-EU, BACnet International, standards, guidelines, proposals, processes, colleagues (you guys are all fair game now***), energy, my camera, energy efficiency, conferences, meetings and more. You get the picture: all sorts of exciting stuff! Live-blogging BACnet committee meetings, ouch!!!

Bandaged foot and bindlestiff, we're off.

* Except my sanity -- am I really setting out on this!?

** We're speaking intent here; this is new territory, there's no map.

*** Not really, but you're duly warned.