Re: X10 AGC and Insteon

["Jeff Volp" <JeffVolp@xxxxxxx>]

Thanks for your input Dave,

Monitoring line noise here with a scope, most noise does not occur in the
X10 sample window.  The most significant noise is from large transients that
occur near the waveform peak.  Then there is a 200mV glitch that
periodically walks its way through the 60 Hz waveform.  Finally, I see an
occasional high frequency burst that seems to be about one cycle long.  It
is not periodic, so I just see it for one scan.  That signal is well down in
amplitude from the X10 signals.  Only one line transient comes in the middle
of the X10 signal window.  It is about 100mV, but certainly causes a few
pulses to be counted with the XTB-II's high sensitivity.

Now I am using just the X10 sample window, and reducing the sensitivity if
there are a series of counts above 12 cycles on multiple sequential half
cycles.  It seems to work pretty well for the type of noise I see here
except for the random high frequency burst.

If I did open up the AGC to sample the full cycle, those large transients
near the peak would reduce the sensitivity more than necessary.  I'm also
not sure how to deal with that random high frequency burst if it really is
only there for a cycle at random times.  At maximum sensitivity it could
look like a collision if its frequency is in the X10 range.  I'm thinking
about a fast attack AGC loop sampling outside the Insteon/X10 transmission
window, but after the glitches that occur near the waveform peaks.

Jeff

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:453cd54d.889944843@xxxxxxxxxxxxxxxx
> I would sample outside the X-10 and Insteon windows. Any noise that's
likely
> to be troublesome is likely to be present outside these windows. Basing
your
> threshold on the general background noise level makes more sense to me
than
> the "gated AGC" that others use.
>
> However, it might be a problem should someone encounter another system
using
> the powerlines outside of the X-10 & Insteon windows.
>
> If you haven't already done so, you might explore how X-10 does it with
the
> CM15A.