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[JeffVolp]

I hope those modified Tuned Signal Suckers will be sufficient.  They are MUCH cheaper, and available now.

Jeff

[Dan Lawrence]

I sincerely hope you can get what we all might eventually need to cope with Smart Meter noise.   

[JeffVolp]

In a report back on the TSS tuned to 75KHz, there have still been several missed commands and false actuations.  Further monitoring of the powerline showed another signal at 86KHz, which is not now being attenuated by the TSS.

I am working on a dual-frequency design now that will attenuate both 75KHz and 86KHz.  It can also be used to attenuate the 115KHz and 132KHz pair, which are the other LonWorks frequencies.  However, because those are so close to the X10 120KHz, it will not be as effective at those frequencies.

Unfortunately, I think the only real solution will be the noise eliminator.  Simulation shows that should do the job if located adjacent to the distribution panel.

Jeff

[JeffVolp]

An update on the Noise Eliminator:

Simulations show something like this has real promise, and I was getting ready to order parts to build a prototype of the output stage.  However, BUF634 is pretty expensive - about $10 each.  And 4 or 5 would be needed on each phase to counteract the 1A drive capability of the LonWorks transceiver.  With all the other components needed, an assembled unit will be in the $300 range.

While a unit like this should eliminate the smart meter problem and also null out in-home noise that reaches the panel, that may be more than most X10 users would be willing to spend for a solution.

Comments?

Jeff

[Noam]

Jeff -
I'm amazed that you haven't given up on this one yet (I'm the same way, though - I just can't let go of an unsolved puzzle).

I'm guessing that $300 might be too high for most X10 users, but perhaps there may be some users out there who would spend that much just to make their system work again.

If it were me, however, I would probably just take the money and invest in some other system (Insteon, Zigbee, etc).

[Brian H]

I have not see any reports yet. But there is a good chance if it makes X10 unreliable. Insteon may also have a similar fate.

[JeffVolp]

If it were me, however, I would probably just take the money and invest in some other system (Insteon, Zigbee, etc).

Yes, that is my concern.  However, many of us have thousands of dollars invested in X10 compatible equipment (Leviton here), so preserving that investment may be worth it.  If they slap a smart meter on our home, I'll build one up just for myself.  That is why I am continue to pursue the design.

Jeff

[dave w]

I wonder if the power company would kick in money? They (through Lonworks) are now interfering with PLC communications which has been a standard since the 1980s. Naturally they won't care. So, we the consumer, need something to mess up their Lonworks communications. Once they have to send troubleshooters and meter readers to X10 homes, they may be more sympathetic. So we need something cheap that wipes out Lonworks.  

[JeffVolp]

So, we the consumer, need something to mess up their Lonworks communications. Once they have to send troubleshooters and meter readers to X10 homes, they may be more sympathetic. So we need something cheap that wipes out Lonworks.  

Since the noise eliminator would null out the LonWorks signal at the distribution panel, it would probably render their communication inoperative too.

Just a high-power nulling amplifier is pretty simple, but what makes this more complicated is being able to handle X10 signals.  A simple nulling amplifier would cancel X10 signals just like any other noise, so potential X10 signals must be decoded, validated, and then repeated with enough power to overdrive the incoming LonWorks signal.

Jeff

[dhouston]

They (through Lonworks) are now interfering with PLC communications which has been a standard since the 1980s.

It has never been an official standard and has always had to share the powerline with all comers. There were commercially available wireless FM intercoms that used the powerline as far back as the early '60s as I personally installed one in a restaurant in Palo Alto, California, where there was no conduit between the maitre'd stand and kitchen, in 1962-63.

OTOH, if this makes the meter run backwards, it might pay for itself fairly quickly. 

[dave w]

It has never been an official standard and has always had to share the powerline with all comers.

Yeah, I should have called it "the defacto standard" like Dave Rye does.
Maybe this is viewed by X10 as another nail in the X10 PLC coffin, along with switching power supplies and evil incandescent bulbs. Another reason to get out of the business.

[Noam]

Since the noise eliminator would null out the LonWorks signal at the distribution panel, it would probably render their communication inoperative too.

Just a high-power nulling amplifier is pretty simple, but what makes this more complicated is being able to handle X10 signals.  A simple nulling amplifier would cancel X10 signals just like any other noise, so potential X10 signals must be decoded, validated, and then repeated with enough power to overdrive the incoming LonWorks signal.

Is the LonWorks signal continuous, or does it only come sometimes?
If it is intermittent, is there a way to listen for valid X10 codes, buffer them until the LonWorks signal is gone, and then retransmit?

[JeffVolp]

Is the LonWorks signal continuous, or does it only come sometimes?
If it is intermittent, is there a way to listen for valid X10 codes, buffer them until the LonWorks signal is gone, and then retransmit?

I only have data from one smart meter installation.  That meter is communicating at both 75KHz and 86KHz.  The communication in this one instance is periodic.  As I recall, it occurs about once a minute.  I don't think he recorded how long each transmission is, but it is long enough to measure the frequency and amplitude on a spectrum analyzer.

These signal bursts are causing both the loss of X10 commands and unwanted actuations.  I have seen noise morph one command into another, so that may be what is happening here with the unwanted actuations.

A "polite" controller may be able to recognize the corrupted commands and retransmit.  That should help with lost commands, but may not help with unwanted actuations.

It may be feasible to build a repeater that could recover a X10 signal buried in the meter transmission, and retransmit that when the line has cleared.  However, that opens the door for all sorts of unexpected results if the smart meter transmits in the middle of a sequence of commands.

I think the only real solution here is to somehow eliminate the smart meter signal from propagating into the home.

Jeff

[Noam]

It was a crazy idea, but I don't really know how these things work in the first place.

Would something in-line between the meter and the breaker box be able to filter out the noise easier? Like a step-down transformer, but not actually stepping down?

[JeffVolp]

Would something in-line between the meter and the breaker box be able to filter out the noise easier? Like a step-down transformer, but not actually stepping down?

Yes, a filter between the meter and the distribution panel could block the signal.  One of my customers had a PZZ01 installed.  As I recall, it helped, but didn't entirely solve the problem.   An in-line filter would typically have to handle 200 amps, and might be pretty large.  Think of a 2-phase version of the XPF that could handle 10 times the current.

But as I said in a prior post, I think the utility companies want this signal to intrude into our homes because the eventual intent is for them to be able to shut down our major electrical appliances during peak demand so they do not need to provide on-line reserve generating capacity.

Jeff