Re: Decora HCPRF WAS: Re: UPB, etc. WAS: Need some antenna advice...

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message

> Reading the docs, are we? Geesh - no wonder things are so confused. ;)

I had to go through a bit of a search to get them, too.  I lost the little
paper insert and then realized that the house and unit code are set via the
programming button.  I didn't remember how to do that. (old age, I guess).
Leviton never replied to support emails but I finally found the PDF imbedded
in one of their catalogs (had to DL 60MB by modem to do it!).  The funny
part is that I had finally found a use for HCPRF, but that was based on the
mistaken assumption that it was a old-fashioned relay module like the TM751
and RR501 and not a solid state relay for incandescent loads.  I was going
to use it to control some fluorescent lights!  :-(  No such luck!   The one
thing the module has going for it, as opposed to the TM751 is that it's
silent.  My MIL finds the TM751's relay clacking objectionable.

> I did not do extensive testing with the HCPRF. Once I saw there was no
room
> to add an external antenna jack, I lost interest.

Too bad.  I can afford to experiment on mine and might have taken a whack at
modifying it just out of curiosity.  It's definitely not happy within my
current setup.

> What unit codes are you seeing the strange behavior on?

On a number of different codes.  B13 is the most popular inadvertent turn on
(and off) but others do it as well.  I should add that these units are
controlled by the infamous Hawkeye PIRs.  As I wrote that, I realize I may
have blown a couple of 100 bucks on the Lynx.  The collisions may be
occurring in the RF portion of the "control sequence."  :-(   I used to keep
the CM11A active, just logging the weird signals but I stopped using it when
it started showing signs of overheating.

> www.mbx-usa.com/multiples.htm gives a very brief summary of what you'll
see
> with multiple transceivers.

Yes, I've been spending a lot of time there, sifting through the diagrams
and data.

Am I right in assuming that there's no error checking like a CRC check of
the *complete* X-10 signal?  I see it as a series of 120KHz tones
synchronized to the zero crossing.  When a receiver sees 3 or more tone-free
AC cycles it is then "primed" to look for a "start code" of  "1110" which,
for a standard X-10 transmitter, is a series of 9 pulses, total.  Six of
those pulses are ignored, as they are for split phase systems zero
crossings.  The Powerlinc appears to differ in that it only sends pulses on
one phase, so the scope trace looks a lot like the actual binary string
transmitted.

My understanding is that whatever error checking occurs, it's in
representing a 4 bit binary number like 1001 in 8 bits using a bit's
complement to guard against errors.  So 1001 would become 10010110.  The
only place this does NOT occur is in the start code, which is just 1110 that
follows at least three signal-free AC cycles.

FWIW, I can't seem to reach the Power Line Communication Bibliography
referenced on http://www.mbx-usa.com/x10-sig.htm
I don't know whether it's me or they've disappeared.  I searched the Wayback
machine for it:

http://web.archive.org/web/20040606020312/http://info.iet.unipi.it/~filippo/
documenti/powerlines/PowerLineCom/FrameRIF.html

otherwise known as http://tinyurl.com/8ghye

and I can retrieve the bibliography list, but the URLs they refer to are
gone, too.  I've tried to pull them one at a time out of the Wayback and
then tried using Google to see if the site's simply been relocated but I
can't seem to find a new version of the site.  :-(

--
Bobby G.