Re: RS485 - XPL on the wire

["g8kmh" <lehane@xxxxxxxxxxxxxxxxxxx>]

Yes but they tend to be 'big' whereas serial comms is much simpler,
even Canbus.

I think to summarise:
Without additional overhead xPL on RS485 isn't robust enough to meet
expectations and needs to better than X10.
Either an additional protocol is implemented (token, master/slave,
whatever) or we go down a different route and for dumb devices do not
put xPL on the wire but translate. Canbus then becomes more
attractive since the small frame size lends itself to encoding.

Lehane


--- In ukha_xpl@xxxxxxx, "Mal Lansell" <mlansell@f...>
wrote:
> Can't we just use the LAN?
> Are there any ethernet-enabled PICs out yet?
>
>
> ----- Original Message -----
> From: "Frank Mc Alinden" <fmcalind@b...>
> To: <ukha_xpl@xxxxxxx>
> Sent: Friday, October 22, 2004 12:23 PM
> Subject: Re: [ukha_xpl] Re: RS485 - XPL on the wire
>
>
> >
> > > I also found this:
> > > http://caraca.sourceforge.net/
> >
> > Im not 100% sure but i think that Canbus is suited to txing /
rxing small
> > data packets
> >
> > > Indeed, the original intention was xPL on RS485..since xPL
already
> > > has addressing. I took a rather simplistic view that in HA
you
could
> > > afford a few collisions and that devices aren't transmitting
very
> > > often. It was also only around simple devices like light
switches,
> > > temp sensors, etc.
> >
> > Would be nice to have it work like cbus were theres no
master.......
> >
> > Frank
> >
> >
> > ----- Original Message -----
> > From: "g8kmh" <lehane@m...>
> > To: <ukha_xpl@xxxxxxx>
> > Sent: Friday, October 22, 2004 9:15 PM
> > Subject: [ukha_xpl] Re: RS485 - XPL on the wire
> >
> >
> > >
> > >
> > > Indeed, the original intention was xPL on RS485..since xPL
already
> > > has addressing. I took a rather simplistic view that in HA
you
could
> > > afford a few collisions and that devices aren't transmitting
very
> > > often. It was also only around simple devices like light
switches,
> > > temp sensors, etc.
> > >
> > > Others have mentioned DMX/DMX512 and I think there is a
great
case
> > > for an xPL to DMX interface to drive dimmers.
> > >
> > > I also found this:
> > > http://caraca.sourceforge.net/
> > >
> > > Lehane
> > >
> > > --- In ukha_xpl@xxxxxxx, "Mal Lansell"
<mlansell@f...>
wrote:
> > > >
> > > > > Hi All,
> > > > >
> > > > > http://www.hth.com/easytap/default.htm
> > > > >
> > > > > May be of interest.......
> > > > >
> > > > > I've alsways thought that RS485 was mainly about
the "hardware"
> > > layer.
> > > > >
> > > >
> > > > It is, but I think the OP wanted a method for
transmitting xPL
> > > messages over
> > > > RS485, as opposed to something like DMX, where xPL
would be
used
> > > (by a PC
> > > > application) to drive a DMX controller that then sends
DMX
messages
> > > over the
> > > > RS485 connection.
> > > >
> > > > For sending xPL over RS485, we get to define our own
unique
system,
> > > although
> > > > in the absence of a definite application or hardware
for
this, it's
> > > hard to
> > > > say whether RS485 or some other network (such as CAN or
Ethernet)
> > > would be
> > > > more appropriate.
> > > >
> > > > Mal
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > > SNAP,  http://www.hth.com/snap/ which I know
many are aware
of,
> > > is one
> > > > > protocol that can sit on RS485, as indeed is
DMX512
> > > > > http://www.dmx512-online.com/physl.html
, if I've got this
wrong
> > > feel free
> > > > > to take me into a dark corner and tell me so.
> > > > >
> > > > > Regards
> > > > >
> > > > > Stuart
> > > > >
> > >
> > >
> > >
> > >
> > >
> > >
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> >
> >
> >
> >
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