Re: Understanding X10 Dims???

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Charles Sullivan" <cwsulliv@xxxxxxxxxxxx> wrote in message
news:pan.2005.08.08.21.58.32.976197@xxxxxxxxxxxxxxx
> Robert,
> Thanks for your response.  Yes, Dave's post is clear, but it
> doesn't answer my questions.
>
> I can direct the CM11A to send the same dims multiple times
> (with a few seconds delay in between) but the dims reported by
> another CM11A (looking at the actual byte reported, not converting
> to a percentage) vary by 1/210, occasionally 2/210. Why the
> variation?

Sorry it didn't help.  I thought what you had been describing was that if
you had a pause in the stream, the CM11A now thinks you're sending microdims
so DIM_DIM without a gap gives a 6% dim whereas a DIM DIM with a gap is read
as a two microdims which are 2/210 or 1.2%.  Apparently I'm not following
what you mean by a delay of a few seconds.  Are you programmatically
delaying the interval between DIM commands?

> And what exactly is being sent over the PL which
> accounts for the "retro" effect of the higher (by 1 or 2) dim
> value, which is most noticeable with the LM14A but also observable
> with a standard X10 lamp module.
>
> I was hoping that someone who had monitored the power line with
> something other than a CM11A, or who had knowledge of the
> hardware/firmware with regard to dims, could provide some insight
> into what's happening.

Well, if I understood more clearly what you were looking for, perhaps my
Monterey PLSA in the signal dissect mode would give the raw data you're
looking for.  I'd be happy to run some simple tests if you can set them up
for me.  I have a CM11A in the junk box but it hasn't been used for years.

http://www.smarthomeusa.com/Shop/x10-test-equipment/Item/PLSA/

Explains how the Monterey works in the signal dissection mode:

Sample Screen
DISSECT: 1 0
 CYCLE 02 1.4 03m

DISSECT THE ENTIRE X10 SIGNAL: Each X10 code is transmitted twice using 22
AC power line cycles. Each true bit of code information is transmitted at
the zero-crossing point with a complement bit transmitted on alternate half
cycles. All 22 true bits of the X10 code and their complements can be
viewed. In this example, cycle #2 is dissected to show the true bit as a
Binary 1 with a signal strength of 1.4 volts, and it's complementary bit
(Binary 0) with signal strength of 3 millivolts. This is useful for seeing
the effects on the X10 signal after installing repeater/amplifiers and for
viewing additional codes or data after extended code/data/preset dim
commands.

--
Bobby G.