BACnet communication protocol

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Thread Starter

Ken Irving

I've been wresting with a question... When the OIC (Open Indistrial Communications) Protocol discussions started up, I thought about suggesting BACnet as a possible direction, but decided against it on the basis that the specification is not freely available, and must be purchased (around $120) from ASHRAE. ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers) has been working on BACnet (Building Automation and Control Network) for many years, ostensibly with the goal of it being an open standard. There is no licensing for its use, for instance, and no restrictions on how it may be applied. However, in an effort to recoup costs, ASHRAE charges for the spec, and presumably would not be happy if it were to be, for example, scanned and put on the net. I mentioned this concern on a BACnet discussion list, and the folks there seem to see no reason why BACnet couldn't be used for an open source system. I, on the other hand, can't imagine how it could be, since only those willing to put up the money can even see the spec. I'm not suggesting that BACnet necessarily has any great advantage over other existing or yet to be developed communications protocols, and it is in a niche somewhat to the side of other automation systems, but I'm saddened by the fact that there's a barrier to its use, even a low barrier. It could form the basis for an open system and perhaps see wide use, but is that possible if the spec is not free? Ken -- Ken Irving <[email protected]> _______________________________________________ LinuxPLC mailing list [email protected] http://linuxplc.org/mailman/listinfo/linuxplc
 
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Campbell, David (Ex AS17)

> Ken Irving wrote: > > When the OIC (Open Indistrial Communications) Protocol > discussions started up, I thought about suggesting BACnet as > a possible direction, but decided against it on the basis that > the specification is not freely available, and must be purchased > (around $120) from ASHRAE. *cheer wildly* Some lateral thinking on the list!!! The difference between "Building Controls" and "Industrial Controls" is very small and often differs only in the method applied. One product that Honeywell used to sell (although it has been repackaged & renamed in the last couple of years) was SCAN-3000 (a SCADA package that used third party PLCs as IO). There is another package for building control called Excel-5000 which differs by about 20% of the code base. There has been some "interesting" cross over of code between the two products. For instance, you can be paged at home when a specific alarm event occurs in your process. There is a water supply authority in Australia who use this automatically page an engineer when one of the pumpstations trip (we are talking about a 5 MW drive unit). > ASHRAE (American Society of Heating, Refrigerating, and > Air-Conditioning Engineers) has been working on BACnet > (Building Automation and Control Network) for many years, > ostensibly with the goal of it being an open standard. > > I mentioned this concern on a BACnet discussion list, and > the folks there seem to see no reason why BACnet couldn't be > used for an open source system. ASHRAE charges are to cover administration costs of "maintaining the standard", there is nothing to prevent one person from buying a copy and coding a driver/API for BACnet. Providing the standard was not copied verbatim into the driver comments then there would not be a problem (even if each routine had a single paragraph summary for the section that the routine refered to). David Campbell _______________________________________________ LinuxPLC mailing list [email protected] http://linuxplc.org/mailman/listinfo/linuxplc
 
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Curt Wuollet

Hi Dave. If there is a formal declaration that it is and will alwys be open, I agree it's worth looking at. We do a lot of lateral thinking here on the list, it's just that many commercial concerns call it patent or copyright infringement:^) Now, if I just had $120.00........ Regards cww _______________________________________________ LinuxPLC mailing list [email protected] http://linuxplc.org/mailman/listinfo/linuxplc
 
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> ASHRAE charges are to cover administration costs of > "maintaining the standard", there is nothing to prevent > one person from buying a copy and coding a driver/API > for BACnet. Providing the standard was not copied verbatim > into the driver comments then there would not be a problem (even > if each routine had a single paragraph summary for the section > that the routine refered to). It sounds like there may be such an implementation in the works, but they want to get all the bugs out ;) before releasing it as open source. Don't know when that'll happen, maybe this year? Seems at odds with "release early and often", etc., but if true it will be appreciated. It's still hard for me to imagine how such a thing could be maintained as a world-wide standard if the spec cannot be published freely. -- Ken Irving <[email protected]> _______________________________________________ LinuxPLC mailing list [email protected] http://linuxplc.org/mailman/listinfo/linuxplc
 
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On Wed, Mar 14, 2001 at 08:54:24PM -0600, Curt Wuollet wrote: > > If there is a formal declaration that it is and will alwys be > open, I agree it's worth looking at. > We do a lot of lateral thinking here on the list, it's just that > many commercial concerns call it patent or copyright infringement:^) I can't find any such statement. The cover statement does say that the standard is under continuous maintenance by a committee which meets regularly to discuss addenda, revisions, etc., and that change requests can be sent in for review. BTW, the document is ANSI/ASHRAE Standard 135-1995. It does include a few addenda, and some are available on the web (I think at bacnet.org). > Now, if I just had $120.00........ -- Ken Irving <[email protected]> _______________________________________________ LinuxPLC mailing list [email protected] http://linuxplc.org/mailman/listinfo/linuxplc
 
K
It's worth a try, perhaps, (and maybe a good test) but there seems to be a fair amount of animosity toward the idea of anything free and open. I posed a question on the BACnet list the other day (archives available somewhere), but probably got off on the wrong foot. I made a presumption that the fact that there's a charge for the specification means it would not be possible to support in an open forum. Only those who had paid their $118 could see what is in the spec, and so comment on the code written to it. There are no restrictions on who can buy it, and the goal is for a common protocol. It is aimed at "building automation" systems, but, as others have noted, that doesn't necessarily mean it might not be applicable to generalized automation. There was some discussion of an open, even GPL-licensed, implementation of the protocol, but I think that turned out to be a testing suite intended for checking implementations for compliance. I'm not sure that BACnet is actually applicable to the needs of the LinuxPLC, but it seems a shame to ignore all the work that others have put into this and other efforts. I think there is a need for a protocol that is open, but whether that's OIC, ACPLT, BACnet, etc., I certainly don't know. I'd be willing to attempt to summarize how BACnet is laid out, and could probably find some links to information (though those are often glowing reports and hypeful predictions). Ken
 
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