RE: Newbie - controlling lights and creating scenes (Ocelot?)

["K. C. Li" <li@xxxxxxx>]

On Sun, 1 Jun 2003, Kevin Hawkins wrote:

> I have no commercial interest in X10 or C-Bus - I am just a user of
both.

I seem to recall that you have been offering to obtain C-Bus equipment for
people on the list. If my recall is wrong, I apologise for making the
false statement.

> it was designed again today it would be quicker and more reliable, and

The same can be said about a number of technologies that have been around
for some time. Even ADSL, a modern technology, has become quicker and more
reliable today than only a couple of years ago.

> call a 'long in the tooth' technology - indeed 'IF' PLT can be
introduced in
> a way that doesn't impact our radio spectrum I shall be truly
impressed. I

That is a valid point. As far as I know, the current PLT trial in Scotland
is having an adverse effect on at least a number of amateur radio
frequency bands. eg. 3.5MHz and 7MHz.

> True but it is flawed in that it is not a delivery confirmed transport
and
> it is prone to attenuation and noise. In a small environment it can be
very
> effective. I

I agree it would be nice to have each command confirmed, although the
necessary commands are defined. However, I maintain that a properly
planned X-10 system would make status feedback less essential. All PLT
based systems suffer from attenuation and noise to some degree.

> > unreliable. The second issue is the range of products available
in the UK

I don't think the European X-10 range, assuming that is what you mean, is
that far short from the U.S. range. In fact, there are a few modules that
are only available in Europe. eg. DIN rail modules.

> Yes, but it is a design weakness that makes X10 susceptible to these
issues
> in the first place. I use X10 here and I have areas that work almost
100%
> and areas that just don't work. True I could probably fix this with
the use
> of repeaters, better modules and filtering but the fact remains it is
not a
> system that you can depend on totally.

That is essentially a limitation of all PLT systems, not just X-10. The
power line is a harsh environment to communicate in and it can never be as
clean and dependable as dedicated wiring.

> The Micromodules are relatively new - I assume from what you say they
can be
> placed at one end of an N-way switching circuit and support dimming
with
> intermediate C/O momentary switches if there are such things. I also
assume
> they require no neutral feed ??

Unfortunately, MicroModules do require the neutral wire to operate.

> Status response comes into its own as the only way that you can check
that a
> device has received an X10 command - if you have any modules that are
not
> 100% dependable in their operation it is essential. Plus as most X10
devices

This is only important if computer or offsite control are involved as
sensory feedback is usually adequate.

> do not send a status change X10 message out when they are manually
changed
> by the local switch this is the only way to know when things change
state

Again, this is only relevant if computer or offsite control is involved.

> What are the ways around this >? Do you mean installing current
sensors and
> feedback using wired cables ?

One way to get around the problem of undefined state of modules is to
refresh the state of the modules periodically to their last known states.
A number of home automation controllers do this. eg. Circuit Cellar HCS II
system. I realise that this method is not appropriate in all
circumstances.

> I agree this is my take on the market - but to me the X10 solution
could
> have been made far more attractive and become as prevalent as it is in
the
> US (per capita) with some simple design decisions - the 2 way light
switch
> being one and cosmetics being the other. Whether 2 way is important or
not

I agree. X-10 products do often fall down on their bland and somewhat
clunky styling.

> Agreed - although as Clipsal mentioned at the UKHA meet they have a
totally
> RF based retrofit solution available - at what price and with what
features
> and reliability remains to be seen.

It would be interesting to know what radio frequency the RF based products
are operating on. Both the 433MHz and 2.4GHz bands are becoming
overcrowded with increasing interference problems.

> Ahhh - news to me -  Is SmartLink available in a UK CE approved
version then

Unfortunately not at the moment. It is the CE approved part that is
preventing a number of products from being widely available. This would be
true for all the converted U.S. products and most of "custom
designed"
products.

> Great stuff - looking forward to these - are they bidirectional too ?

Not yet but it is not complicated to add the 120kHz transmitter if
required.

> now for what 15+ years and we still lack some basic products to fill
out the
> range.  Some of this is due to woeful disregard for the needs of the
UK
> market (2 way light switches) etc. I know the products are
significantly

I cannot speak for X-10's development and marketing decisions but I tend
to agree with what you are saying here.

> X10 can be improved , at a cost, by better transmitters, more
sensitive and
> selective receivers etc it is still a tired technology. I think it's
great

If the technology remains adequate and cost effective for what it is
designed to do for most people, age of the technology shouldn't be cited
as a good reason for change. The humble filament light bulb is still going
strong since its invention in 1879.

Regards,

Kwong Li
li@xxxxxxx
Laser Business Systems Ltd.
http://www.laser.com