Re: Understanding X10 Dims???

[nobody@xxxxxxxxxxxx (Dave Houston)]

To add to the record (and confusion), the SmartHome 2000STW goes from max to
min brightness with 14 contiguous dims, 32 singlets or 32 µdims.

Like I said in the post that was quoted at the beginning of the thread, you
really need to know the exact sequence on the powerline. And you also need
to know exactly how the target receiver(s) react to that sequence. I don't
think the CM11A gives you enough information about received dim/bright
signals so it's kinda like playing "pin the tail on the donkey". The CM15A
MCU has access to the raw data but I have no idea how well X-10's CM15A
firmware digests it as my only interest is in replacing their MCU to allow
access to it's full capabilities.

Of course, nothing that uses the TW523 can even come close to reporting
dim/bright accurately.

I have no idea how well SmartHome's PowerLinc deals with this. I suspect it
handles their own modules and switches OK but errs on others.

As manufacturers of X-10 compatible devices proliferate, the confusion can
only grow.

nobody@xxxxxxxxxxxx (Dave Houston) wrote:

>The analysis holds up for triplets, quads, quints & sextuplets but there are
>a few points that might be further refined.
>
>Using the Kill-A-Watt & LM465 w/60W, I measure 145 microsteps to go from max
>to min. This gives a 0.662% value for a microstep with the LM465. Other lamp
>modules and switches may differ - the LM14A takes about 10 more microsteps
>to go from max to min and it's min is far from full dim - my SmartHome lamp
>modules do not respond to microsteps. The exact value for a microstep has
>minimal impact as its effect is overwhelmed by that of the standard step.
>
>The 96% figure is taken from various documentation - most from the same
>experts who were off on the number of microsteps, off on the number of
>standard dims and off on the explanation of how dims work. Someone more
>able-bodied than am I with a Kill-A-Watt might be able to refine this figure
>using a 300W load and measuring with and without the LM465 at max. I'm using
>a small clamp-on gooseneck which is limited to 60W.
>
>With the LM465, it takes 21 contiguous dims to go from max to min
>brightness. Since the first one is a microstep, the value of the standard
>steps is 4.767%. But this might actually be 20 plus some fraction which
>would slightly increase the value of a standard step. A wattmeter with 1/10W
>or better resolution could refine this.
>
>ddl@danlan.*com (Dan Lanciani) wrote:
>
>>In article <ZtidnVUsO8aJx2XfRVn-gQ@xxxxxxx>, ROBERT_GREEN1963@xxxxxxxxx (Robert Green) writes:
>>| "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%.
>>
>>Although a lot of references use this description I do not believe that
>>it is correct.  I think the initial DIM or BRI always results in a micro
>>step regardless of whether it is followed without a gap by additional
>>commands.  See:
>>
>>http://groups-beta.google.com/group/comp.home.automation/msg/0e3445aee7941493
>>
>>So the original poster's '+ X' would always be at least + 1.
>>
>>				Dan Lanciani
>>				ddl@danlan.*com