Preset Dim and Dimming of PCS dimmers

[Thomas D Arman]

<Notes inserted below>
------------------------------------------------------------------
Thomas (Tom) Arman


xtensionlist-bounces at shed.com wrote on 04/17/2005 09:21:47 PM:

> Thomas said :
> >I am using a Lynx-PLC controller and have then set as Smart dimmers.  I 
have
> >turned on X10 Debugging and have analyzed the commands being sent and 
the
> >dimmer's response.
> >
> >Preset Dim 0 - Sends 0 thru  15 for Commanded Preset dims of 0  -->  15
> >Preset Dim 1 - Sends 0 thru 255 for Commanded Preset dims of 16 --> 271
> 
> Just to make sure we're singing from the same hymnal, 
> the Preset Dim command(s) have room for only 4 bits of 'value'.
> 
> The Preset Dim command with the code = "0x0A", can represent 
> values 0 thru 15.
I concur on this.
   > 
   > The Preset Dim command with the code = "0x0B", can represent
   > values 16 thru 31.
This is truly odd as I was sure that I was getting 6 bits of resolution on 
this command
16==0 through 79==63 
When I tried 80 (==64 or hex 0x40) I got the same value as with 16 (==0)
I will retest this when I get home.
> 
> It is difficult to get more than 32 'values' with only 5 bits of 
precision :-)
> 
> So I'm confused about your statement about how the PCS dimmers
> respond to a range of 0 to 79 ... even the Extended Code commands
> can only get a range of 0 - 63.
My units seem to respond to 80 values: 0->15 of the "0x0A" AND 0->63 0f 
the "0x0B"
0->15 from the first followed by 16->79 of the second.   I will send you 
DEBUG info.
> 
> I have never really addressed the 'transparent' handling of the dimmers
> that require the preset dim commands, because most of them actually
> behaved well given normal BRI/DIM commands.
Speaking of DIM, what about the "STEPS" value box in unit dialog?
> 
> It is reasonable to consider the ability to configure a unit as a 
"Preset Dim"
> type of dimmer and automatically issue a Preset Dim command to it
> rather than a number of BRI/DIM commands, but I don't think that will
> happen until after we are finished with the current revisions of the 
multiple
> interface handlers, and the next web interface changes.
That would be great, if we could define to XTension the range of the 
preset values, i.e., the "scale".
> 
> If the PCS dimmers respond well to the Preset Dim commands, then you
> can use a scaling factor of 3.2 for the 'level' in the preset dim 
command :
> 
> preset "PCS Dimmer" to level (50 / 3.2)
> 
> You don't have to do any rounding or modding... that will equate to 16, 
and
> a Preset Dim (1) with a value of 0 will be sent.
Pending my further testing noted above, I think that "preset <dimmer> to 
level 40" would give me ~50% light.
> 
> Let me know what the PCS dimmers do with that logic ?
> michael
> 
> 
>