Re: XTB-II Options

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

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

<stuff snipped>

> TM751s on opposite phases will _ALWAYS_ transmit 1/2 cycle out of step on
> unit codes 1 & 9, guaranteeing PLC collisions. On the same phase, you can
> have as many as desired (at least to the point where multiple PLC
> transmitters attenuate the signal too much).

What I am trying to describe is a situation where two TM751's *don't*
receive the RF command simultaneously.  For example, I had one unit placed
on the floor to receive signals from the basement.  When my wife moved
around in front of it, a press of a Palmpad on the first floor would
generate a flood of "Bad blocks" on the Monterey and we could even
occasionally get a device on another housecode to fire.  My belief is that
her body acted as a shield for the RF and the TM751 that was in her "shadow"
didn't receive the button press until she had moved out of the way.  The RF
transmission in the house is marginal, and depending on who is where and how
they are moving, isn't it at least conceivable that one TM751 sees the RF a
slight moment later than the other whose transmission path had no temporary
blockage?

I can't be sure of the cause, but the Monterey clearly showed the strength
of each bit received and when transmitters were colliding you could see, in
the signal dissect mode, voltage levels that precisely matched the
standalone value of each transmitter for different bits along with what
appeared to be constructive interference, i.e. a signal level for some bits
that was a combination of both voltages.  I'd run some tests except I don't
have collisions anymore and if my wife found out I was inducing them for
study, she'd divorce me.  (-:

>      http://davehouston.net/multiples.htm

Yes, I read through and through that trying to solve the bathroom "flash"
problem.  The Leviton unit shouldn't have interfered with any of the TM751's
but it did.  Badly.  Or else it was inherently defective, which is not out
of the question.

> RR501s and the Leviton HCPRF have collision avoidance. Combine that with
the
> fact that most of the RF signals are sent 5 or more times and they use
> transformerless power supplies that tend to droop when loaded and funky
> things can happen which are hard to analyze.

I'll buy that for sure!  How many RF commands are sent with a one second
push of a PalmPad button?  Just five or does it send as long as you hold
down the button?

--
Bobby G.