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[johnn]

Guys thanks for staying with me.

Tigger, a good question.  Attaching only an
appliance module caused the module to
oscillate on-off at a frequency of around
1on-off cycle per second..  The CM-15A
verified that situcation by showing
incoming commands of alternating B7 on-off
commands in the activity monitor.  The CM-
15A is so swamped, by the noise, it can’t
process anything else.  So, other signals
do not get out on the power lines. And when
they do they are not well formed so they
don’t operate the modules properly.

Donald McMow, you have a good point.  I
called the power company (PEPCO) several
times and received a voice mail system that
gave you 10 seconds to report the
problem.   After not getting anywhere with
that approach, I called the main number and
managed to get far enough into their
service maze to get to a real person.  I
described the problem to her and she said
she would send someone out to check.   I
got a note from the tech saying the
transformer was AOK.  I’m positive he
hasn’t a clue what the noise floor looks
like on our line.

I am trying to find the “right” people to
talk to in the power company about this
problem and see if I can get a better
qualified Tech out to check the noise
characteristics of the line.  On the other
side of that, I’m looking for a
blocker/coupler that would provide me with
the isolation I’ll need from whatever the
source is.  My concern is that the power
company will not be interested in helping
me and I’ll need to work something out on
my own

[donald mcmow]

Are you having any other "wierd" things
happening in conjunction with the noise?
Incandescent bulbs making noise, excess
noise on your stereo equipment/TV or
picture problems, excess noise coming from
other motors or transformers? I would
almost be tempted to have a talk with an
electrician and see what his take is on the
problem. Maybe he could point you in the
right direction as to a person to talk to
at the power company.

[carmine pacifico]

JohnN

I find next to impossible that power line
noise can generate an exact X10 signal, the
bit in the positive half cycle are
complemented on the negative cycle, the odd
that a complete house code address plus
on/off  signal is generated are less than
winning a lottery.
Have you tried just you appliance module?
No other X10 transmitter plugged in ?(that
includes any 2 way X10 devices).
With just the appliance module plugged in
if you still have problem try a different
house code + address, if problem persist,
than you do not have a simple noise
problem, your power may be unstable, a
large AC motor with defective speed control
can alter the power line cycle enough to
wreck havoc to electronic equipment.
I would recommend to visually inspecting
the power line with a scope you should have
a clean sine wave.
Any energy efficient appliance can be the
source of problem when they malfunction:
lights ballast, variable speed control
furnace motor …….

[billy]

Did you try the appliance module at your
neighbors on either side of your house? If
they are fed from the same transformer that
could give you more info on the source of
the problem. If it does exhibit the ghost
commands at your neighbors, try turning off
the main breaker in your house to eliminate
that source.

Good Luck!

[Tigger]

 
Hmm.

Do you, or perhaps a neighbor have an ADEMCO
Lynx alarm panel?

These panels, and some other Ademco panels
have an X10 interface, and when in the ALARM
mode, can transmit a repeating On/Off
command on either unit 7, or 8,
in response to an alarm.

A malfunctioning panel might be sending
out the signal continuously. . . .

Just a thought.


T

[Tigger]

(If it IS an alarm panel, transmitting PLC
commands, unplugging the transformer will
stop the transmissions from reaching the
power line.)


T

[johnn]

Donald, No nothing else in the house is
behaving badly or even suspiciously.  The
only exception is a pair of “wireless”
intercoms that modulate the house wiring.
They are very noisy.

Carmine, I can’t agree with you more.  That
last little experiment threw me for a loop.
There is no way random noise is generating
perfectly formed X10 signals in a precise on-
off sequence.  I do not have any other
transmitting device in the system
currently.  No CM-15a, no TM751, no
amplifiers or repeaters and no 2-way
modules.  Everything I have is either a lamp
module, dimmer switch, appliance module or
an appliance socket.  Besides, all of these
were… at some point… switched off when I
turned the power off and the signal did not
go away.  I’ll try other house codes, but
I’m fairly sure that only the B7 code will
be active.

Billy, good suggestion.  I will try that.

Tigger, what a very interesting
possibility.  I don’t think I have any of
those panels.  However, the one thing that
did stay active was my alarm system.  The
power was off, but the system has a backup
battery.  I am going to disconnect it at the
power source (transformer) just to make
sure.  Also, it is very possible that one of
my neighbors has one of these panels.  This
seems like the most plausible explanation.
I will try and track this down with my
neighbors, after I have checked my home.

Stay tuned guys and gals.  For what I hope
will be the exciting conclusion of this
serial.

[carmine pacifico]

JohnN

If you try different house code and /or
address, and the problem is solved, then
most likely one of you neighbour is using
X10 based devices else, in this case a
coupler/ blocker installed on the main
panel will solve the problem.
The best coupler/blocker are the one
installed in the power panel, the neutral
wire is inserted trough the device.
There are many devices that are X10 capable
like my hard wired DSC 832 alarm panel;
based on the information provided I am sure
there is a device within you home or
neighbour that is transmitting the code.

[johnn]

A happy ending after all…  at least for the
interference problem.

When we last left JohnN, a relentless B7 on-
off sequence was bombarding his system and
consumed his CM-15A.  After fully testing
his home he concluded that something from
outside his home possessed his system.

Initial calls to the power company were
unsuccessful.  However, along the way he
ran into a fairy godfather, who pulled some
strings and got one the company’s best
wizards (investigator) out to help.  The
wizard was able to find the other 6 homes
on his transformer and then proceeded home-
to-home to find the home possessed with the
demon (offending X10 device).  As is
normally true in stories and life, the last
home proved to contain the demon.

JohnN, convinced that the problem lied in a
rogue alarm panel sending an alarm
sequence, searched the enchanted home for
the devilish panel.  To his chagrin the
enchanted home did not have, nor ever had
an alarm panel.  So, circuit by circuit the
wizard and JohnN searched to find the
demon’s circuit.  Once found they searched
high and low for the devilish device.
Finally, not finding anything inside the
house and in desperation they looked
outside.   And what did the find?   A flood
light with a motion sensor.  A quick flick
of a switch and the demon was exposed and
subsequently vanquished.

Now JohnN can happily join his friend to
vanquish the remaining demons in AHP.

THE END….. or a renewed beginning?

To all a very sincere thanks for all the
support.  I can assure you I would never
have solved this without it.

[me too]

Was the motion detector in your house?  What
brand and model was it?

[johnn]

DXPPass, The unit was installed in my
neighbor’s home.  The neighbor’s home shares
a power transformer with my home.  From the
looks of the unit, it has been there for
quite some time.  It was located on the
second story of his home, so I couldn’t get
any detailed information about it.  However,
the unit looks allot like X10’s  “Dual
Floodlight Outdoor Motion Monitor” part
number PR511-S, which has a built in X10
interface.

My neighbor’s unit failed such that it was
sending out continuous B7 on-off sequences
over the power line.  Our power is quite
clean so the signal was strong and running
24/7.  Basically, it was swamping my CM-15a
so that it couldn’t respond to any other
command.