Re: Cause of some major X10 problems found

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
>news:46e75eba.1652704109@xxxxxxxxxxxxxxxx
>> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:
>
><stuff snipped>
>
>> >Actually, I believe that the laws of probability are being very
>accurately
>> >represented by what we're seeing.  The odds of creating lots of simply
>> >random noise are quite high.  The odds of creating noise that the
>Monterey
>> >reports as BSC's - the right start pattern followed by garbage - are much
>> >lower.  The odds of creating a valid code out of random bits are very,
>very
>> >much lower.  But I don't believe they equal zero and that's based on the
>> >reports we see of lone activations in the middle of the night.  Based on
>the
>> >X-10 propagation speed, and the length of a day, the occurrence rate
>might
>> >be one in 10,000 or even 100,000.  I feel that sort of "once a day"
>> >probability lines up better with the random code generation theory than
>the
>> >Bloom theory, which should have lights turning on faster than one could
>turn
>> >them off.
>>
>> If you mean once every 100,000 years, I agree.
>
>I may have missed it, but I don't see how the "Bloom Theory" can account for
>the repeated posts we've seen about stray codes in the middle of the night
>or even explain Bruce's situation.  What mechanism would cause a relative
>stable source of noise like the PS to flare up at 4AM, as Bruce reported his
>"turn ons" occurred, after apparently being unaffected for many hours before
>that?  The Bloom theory seems to imply that soon after being exposed to
>noise, the susceptible switches would activate.  But that's not what we see.
>Previous phantom activation reports tend to match Bruce's, often reporting
>that sometime, late at night, random lights come on.
>
>The word "random" was in Bruce's post and a number of others.  That, in my
>mind, implies that various switches activate at odd hours in the middle of
>the night.  I can't help but believe that reflects the noise source finally
>spitting out a code that a switch will react to after spitting out 10s or
>100s of thousands of noise bits.  It's the M and J status codes that are
>reported most often and, as you point out, those are constructed on the
>binary level to be the most likely created by noise bits.  Add to that Dan
>Lanciani's comment about some switches not parsing the ones' complement bits
>in the right way and those stray activations look more and more like a
>reaction to a single code and not some noise spike.
>
>The Bloom model seems to fail when it comes to explaining why it would take
>a spike susceptible module 4 or 8 hours to finally succumb to a spike and
>turn on.  The "Green" model of random noise finally creating a signal a
>switch responds to after 100,000 attempts fits much better with the observed
>data.  It's also bolstered by Jeff's observation of two CFL's interacting in
>such a way that an X-10 switch could be activated by the bit pattern they
>created.
>
>> The fact that grounding the pin fixed the problem rules out that the
>switch
>> was reacting to some aberrant PLC pattern that would not be reported by an
>> X-10 interface.
>
>As I said before, the Bloom model can explain some abhorrent aberrant switch
>behavior like your case, but it fails quite fully to explain why switches
>would "wait" four or more hours to finally give into the noise that the bad
>power supply has been emanating for all that time.  That "magic spike"
>scenario sounds even stranger than the "magic created code" one because it
>so clearly fails to account for the long delays.
>
>The "Green" theory, on the other hand, explains it nicely because good codes
>emanating from a noisy power supply happen very rarely, as one might expect.
>Not so rare that they never happen, but rare enough that it takes quite some
>time for the noisy PS to create them.
>
>> Nor is there any reason to believe that X-10 would have
>> designed switches and modules that responded to patterns that would not be
>> reported by interfaces designed by the same people.
>
>There may be no reason to believe it, but I believe Dan L's discovered that
>existing switches don't execute the one's complement function for every
>slot.  I believe that's your main objection to the possible existence of
>these generated codes.  If so, a failure in the error correction detection
>HW could allow bad bits to trigger the device anyway.
>
>> Analyze away but count me out - I haven't been on a snipe hunt in over 60
>> years.
>
>I can understand why.  If you did happen to find the snipe, you'd have to
>eat another avian dish, namely crow.  (-:  No one likes having to do that.
>I just watched a program about the man who had captured all the data
>required to prove the existence of other planets, but failed to interpret it
>correctly before another researcher, looking at the data the first had
>posted, was able to make sense of it and prove the existence of other solar
>systems with planetary bodies.  Needless to say, he was not a happy camper.
>
>Hopefully Jeff will take up the hunt.  It would be another feather in his
>cap to demonstrate that his new XTB-IIR could take such devices in stride
>without missing a beat. He also has the smarts and the analytical hardware
>to capture any code the power supply might create.  Besides, it would be
>nice to prove or disprove the "created code" issue for once and for all, and
>in practice, where it counts, rather in theory.  The fact that he's seen
>such created codes already when not really looking for them leads to me to
>believe that he'll have little problem finding them when that's what he's
>searching for specifically.
>
>If Jeff declines, and Bruce agrees, I'll take up the hunt.  If I put the PS
>behind a filter with a Monterey and a CM11A so both can log the output AND
>add a video camera to record all of the Monterey's readings, I think we'll
>see that devices like PS's can indeed create codes that X-10 devices respond
>to.  The only potential problem I see is that the PS may have been
>interacting with another device in Bruce's house much the same way that Jeff
>described the two CFL's interacting to create X-10 like signals and its
>behavior will be different on my test bench as a result.  Even if that's the
>case, I have some very noisy CFL's that might be used to "beat" against the
>noise signal from the power supply.