X10 Community Forum

💬General Category => General Discussion => Topic started by: pconroy on September 03, 2010, 09:54:27 PM

Title: M13
Post by: pconroy on September 03, 2010, 09:54:27 PM

Yep - M13.
Log is showing M13 is triggering.
Only thing is I'm pretty sure I didn't set a motion sensor for M13. 

<sigh>
 B:(



 rofl

Title: Re: M13
Post by: J.B. on September 03, 2010, 10:19:10 PM

I've been getting a random M1 code with a DS10A triggering but it's mapped to H12!  :)%

Title: Re: M13
Post by: JeffVolp on September 03, 2010, 10:44:12 PM

M13 is all zero's, and is one of the data patterns that sometimes shows up in the presence of noise.

Jeff

Title: Re: M13
Post by: J.B. on September 03, 2010, 11:14:30 PM

That's something I wasn't aware of. Thanks for the info, Jeff.
Hoping to pickup an XTB-IIR here in the near future. Recently moved into a new location and have had some issues with noise. Few XPPFs have helped some but not everything is working 100%.
Would M1 being sent possibly be noise related also?

Title: Re: M13
Post by: JeffVolp on September 04, 2010, 10:46:40 AM

M1 has a more complex data pattern that would be difficult for noise to produce.

Actually, the data pattern transmitted on the powerline is comprised of the data and its compliment, preceded by a 1110 start pattern.  So M13 on the powerline is actually:

     1110010101010101010101

A burst of 120KHz just after a zero crossing of 60Hz is decoded as a logic "1".  If the noise is slightly different on positive and negative half cycles of 60Hz, and the noise amplitude is just right, it is possible for it to create the 010101... pattern.  Then if there is some transient that interferes with the background noise in such a way that it creates the start pattern, it is possible for a X10 module to decode the noise as M13.  I have witnessed several instances where my set of noisy CFLs used for testing were able to create a valid X10 command this way.

Another likely pattern is J Status Request:  1110101010101010101010

That only needs a little extra burst of noise added to the background to produce the start pattern, and I suspect that is what my CFLs were able to create.

Jeff

Title: Re: M13
Post by: pconroy on September 05, 2010, 01:00:36 AM

Quote from: JeffVolp on September 03, 2010, 10:44:12 PM

M13 is all zero's, and is one of the data patterns that sometimes shows up in the presence of noise.

Jeff

w00t and Cool - I didn't know that!
Thanks Jeff!

Title: Re: M13
Post by: J.B. on September 05, 2010, 01:26:32 AM

Yes, thanks again for the info.
One thing I like about these forums is you learn something new every day!

On a side note, I'm now anxiously awaiting the arrival of a brand spankin' new XTB-IIR.  8)

I'm confident this and my several filters will greatly assist in my signal level and noise issues.  >!