Re: Building control standards

[Ole Trøan <[e-mail]>]

Kerry,

> No problem.  I am not familiar with some of the standards you mention.
> The problem comes in when these "last meters" protocols develop their own
> proprietary data links.  BACnet is in that camp currently with MS/TP, which
> is one of several data links that it supports but the only one that does not
> already have a "IPv6 over foo" RFC.  As the larger vision is to transition
> BACnet to native IPv6 in the future, I believe that draft-ietf-6man-6lobac
> is a necessary step on that path since it is so widely deployed in commercial
> building automation systems.  It is about a factor of 10 less costly than
> ethernet per driver, can cover long distances (1000-1200 m), and has a
> sufficient data rate for the BAC application (up to 115.2 kpbs).
> 
> That said, in conjunction with changes being made in parallel to the data
> link (through a BACnet standard change proposal), I think that MS/TP can
> fill a niche at the low end of wired data links (similar to the niche that 6LoWPAN
> fills in wireless) and will transport arbitrary IPv6 packets up to 1500 octets
> in length (not including the IPHC dispatch header, and depending on link
> MTU setting).  To the extent that the standards you mention will exchange
> their application data using standard IP transports, and the required data
> rate is 115.2 kbps or less, then IPv6 over MS/TP should be a viable option.

thanks for your quick reply!
KNX also refers to ANSI/ASHRAE 135   (http://www.knx.org/knx-standard/introduction/)
so I can only hope that the work on MS/TP will also cover Europe.

cheers,
Ole