RE: X10 Schema best-practice

[Johan Helsingius]

At 12:16 06/03/2004 +0000, Edward Pearson wrote:
 
<blockquote type="cite" class="cite"
cite><font face="arial" size="2"
color="#0000FF">I'm
writing a CM12 connector as an exercise in using the xAP framework. I'm
trying to decide on whether it should present its xAP interface as an X10
schema or a lighting schema (or both). My request for X10 best-practice
was to see if there was anything generally agreed out there already that
I could rapidly implement so the connector would be useful for folks
other than myself. </font></blockquote>
Well, seems all previous efforts have been based on the "expose X10,
warts and all" kind.
But I think it kind of defeats the whole purpose of xAP.
<blockquote type="cite" class="cite"
cite><font face="arial" size="2"
color="#0000FF">Personally
I think X10 stinks so I'll not be going to the trouble of designing a
schema for it myself, I'd rather spend the time thinking about what a
basic lighting schema might look like and prototyping around
that.</font></blockquote>
Exactly!
X10 is a good example of what happens when hardware engineers try
to design a communications protocol. OK, I can understand that true
2-way
with acknowledgements would have required additional hardware, but
the lack of an absolute dim command is just criminal! And the
braindead
separation of address and command into separate messages...
&nbsp;
<blockquote type="cite" class="cite"
cite><font face="arial" size="2"
color="#0000FF">There
are some arguments in favour of an X10 schema such as this:-</font>
<font face="arial" size="2"
color="#0000FF">X10 has become a very broadly
used and well understood protocol to the extent that many home automation
contollers (hardware device or software package) use it as the model they
reveal to the end user - this is sad but true.&nbsp; Normally these
devices connect to the X10 adaptor (CM12/CM11) by directly attaching it
to a serial port - having an X10 schema is a way of enabling
network-connected X10 adaptors that could be used without direct
connection. So in world where change is incremental is seems advantageous
to have an X10 schema to allow gentle migration for existing products
towards xAP.</font></blockquote>
OK, so yes, maybe a "legacy" x10 schema is called for - but
then maybe
we just need a generic "pass bytes" schema. But for new
applications
we need a function-based schema - I really don't want all my
components
to have to know about the horrors of X10.
&nbsp;
<blockquote type="cite" class="cite"
cite><font face="arial" size="2"
color="#0000FF">An
example of a network enabled X10 interface would be a CM12 plugged into a
Lantronix MSS100
(<a href="http://www.lantronix.com/products/ds/mss100/index.html";>http://www.lantronix.com/products/ds/mss100/index.html</a>)
where the MSS100 had been customised to talk
xAP.</font></blockquote>
Right. But can you get Lantronix to implement xAP?
I might be able to get these guys to implement it, as I'm an
investor
and on their board:
<a href="http://www.violasystems.com/";
eudora="autourl">http://www.violasystems.com/</a>
Their eserv is pretty similar to the Lantronix box.
<a href="http://www.violasystems.com/device_servers.php";
eudora="autourl">http://www.violasystems.com/device_servers.php</a>
&nbsp;
<blockquote type="cite" class="cite"
cite><font face="arial" size="2"
color="#0000FF">It
is true that very few X10 devices report status. But there are plenty of
applications where it's useful to be able to receive X10 messages - the
one I'm interested in is receiving X10 messages from an IR7243 controller
that picked up a transmission from a Pronto remote and passes them into
the xAP world.</font>
</blockquote>
Absolutely. But the way I read the drafts they *required* support
for
status reports.
<x>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</x>Julf