RE: xPL/xAP was Re: Re: MusicLobby Users?

["Kevin Hawkins" <lists@xxxxxxx>]

> -----Original Message-----
> From: David Buckley

> Sent: 04 September 2003 23:35

>  The great thing (and great problem) with xAP/xPL is they are both

>  semantically very rich.  Kitchen sink rich.  Conversion and
>  interpretation (and indeed understanding) was never going to be
>  easy :-)  Its highly appropriate for complex data, but I'm know
>  there are some who (despite such fixups as targeting) still argue

>  its just too heavy and too unfocussed for most "real world"
home
>  automation applications.  Both EIB and CBus manage with
relatively
>  tiny messages, yet cover a massive range of real world devices.

I know nothing about EIB - but a bit about C-Bus - whilst it's true that
C-Bus does encompass a large number of real world devices they are
connected
via C-Bus interfaces and manufactured ONLY by Clipsal - and therein lies
the
whole problem - it is a proprietary and closed protocol. They are also
predominantly ON OFF or simple LEVEL based devices. If Clipsal don't make
it
you can't have it. I have seen this in painful detail for example when
trying to support the C-Touch lcd screen from C-Bus2  - the protocol is not
capable.  This was for a trivial task of displaying CallerID on the screen
!
There is no text transfer feature within C-Bus2. So whilst it is small and
efficient it is most definitely not a 'real world HomeAutomation protocol'
for today's more capable devices. The biggest issue though is that it locks
you in Clispal land - unless there was a xAP gateway or a multiple protocol
controller like HomeBrain !
xAP -and xPL are intended to interconnect many disparate devices
with many different data formats and needs - your kitchen sink analogy is
basically true - and that inherently means that they provide an open and
flexible protocol, they use an English type syntax as a common foundation.
In a modern HA environment people need more than ON OFF and LEVEL - and
they
need more than any single manufacturer can offer product wise - and there
are existing products to integrate, particularly in say the AV arena.
We currently have islands of security, communication, databases,
the internet and entertainment including audio and video in many formats
and
sources plus the associated home routing and control - all of these crying
out for integration.  Now that's one tall order for anything - but xAP and
xPL go a long way to building bridges to those islands.
I know of little else within the capabilities of the HA community
that can achieve this, particularly with support for legacy hardware -
meaning everything in your home currently. xAP and XPL are essentially very
simple in concept but capable of handling very complex (= real world HA)
scenarios.

Kevin