Powerline modem

Discussion of modems, ISDN and cable modems.

Powerline modem

Postby Gireesh » Mon Feb 07, 2005 12:35 pm

Hi all,
I'm engaged in designing a powerline modem. and i'm in search of a
perfect IC for that.
I found HCPL800J DAA with DSP56F801 PLM ?
Is there any one who worked on this ?
Can abnybody suggest me better ICs ?
I need a range of atleat 1 km and the application is Automatic meter
reading
Gireesh
 

Re: Powerline modem

Postby Rick Merrill » Mon Feb 07, 2005 2:37 pm

If you have a EE PHD from MIT, go for it. Do you realize that the high
fequency transmission characteristics of most peoples "powerline"
changes constantly and essentially randomly? - RM
Rick Merrill
 

Re: Powerline modem

Postby Joerg » Mon Feb 07, 2005 11:00 pm

Hello Rick,

For power metering it seems that the OP only needs a very narrow channel
bandwidth. The challenge will be mostly in the analog and filter design
arena but it can be done. Then, of course, there are the transformers
that need to be bridged.

Regards, Joerg

http://www.analogconsultants.com
Joerg
 

Re: Powerline modem

Postby Jim Thompson » Mon Feb 07, 2005 11:27 pm

The two remote electric power measurement schemes I know of:

(1) RF transmitter at your meter, "neighborhood" receiver located on a
pole, then connection to phone lines.

(2) Modem connection between your meter and *your* phone line. Power
company polls your modem.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
Jim Thompson
 

Re: Powerline modem

Postby Don Lancaster » Tue Feb 08, 2005 1:02 am

I guess I was involved in the earliest of powerline carrier
communications. Back in 1961 at Femco.

It did not work then and it will not work now.

Ferinstance, an ancient Diablo 630 printer has such a good noise filter
that it takes out any X-10 device within 200 feet.



--
Many thanks,

Don Lancaster
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
voice: (928)428-4073 email: don@tinaja.com

Please visit my GURU's LAIR web site at http://www.tinaja.com
Don Lancaster
 

Re: Powerline modem

Postby Rick Merrill » Tue Feb 08, 2005 1:58 am

There is work that has used cell phone methods to dynamically adapt the
power frequency to fit the power line characteristics. Remember, anytime
an expert says something can be done, he/she is probably right; and
anytime an expert says something can not be done, he/she is probably
wrong. - Rm
Rick Merrill
 


Re: Powerline modem

Postby Joerg » Tue Feb 08, 2005 2:33 am

Hi Don,

It did not work then and it will not work now.


Not for broadband. But for low BW communication it can.

Ferinstance, an ancient Diablo 630 printer has such a good noise
filter that it takes out any X-10 device within 200 feet.


Even a brandnew color printer/scanner did that out here. Had to crack
out the toroid box and give it an individual choke per wire plus a cap
which fixed the problem. Lots of people in our neighborhood keep stashes
of Aspirin or Tylenol. I maintain a bucket of $43 toroids.

But remember, X10 is an ancient AM protocol with little noise tolerance.
Then I found that almost all modules were off from carrier frequency so
after tuning them all up this increased liability greatly. If a suitable
multi-frequency narrowband protocol was adopted this kind of appliance
control would work like a champ. It's just that nobody seems to do it,
they don't see the market potential..

As to power metering I probably would first sit down with the financial
people of a cell phone carrier. It doesn't take a lot of their currency
(kb/sec) per account to transfer a meter reading.

Regards, Joerg

http://www.analogconsultants.com
Joerg
 

Re: Powerline modem

Postby James Knott » Tue Feb 08, 2005 2:41 am

Joerg wrote:

Lots of people in our neighborhood keep stashes
of Aspirin or Tylenol. I maintain a bucket of $43 toroids.

Aren't they hard to swallow? ;-)
James Knott
 

Re: Powerline modem

Postby Peter » Wed Feb 09, 2005 2:29 am

With very low channel width and appropriate signalling you do not need
to bridge transformers. However if complex tariffs are envisaged
there may be a need for transmitting up to 24 readings a day per meter
and this may be beyond such systems.
Peter
 

Re: Powerline modem

Postby Ron Hunter » Wed Feb 09, 2005 3:03 am

The main bar to this type of information distribution is the need to
bridge transformers along the entire data path. This adds cost (and
service delaying infrastructure) to what would otherwise be an already
'in place' data path. It certainly has advantages in simplicity over
other services.


--
Ron Hunter rphunter@charter.net
Ron Hunter
 

Re: Powerline modem

Postby John » Wed Feb 09, 2005 3:03 am

Don Lancaster wrote:

I guess I was involved in the earliest of powerline carrier
communications. Back in 1961 at Femco.

It did not work then and it will not work now.

Ferinstance, an ancient Diablo 630 printer has such a good noise filter
that it takes out any X-10 device within 200 feet.

Powerline communications doesn't work in the 21st century? Really? Gosh
somebody forgot to tell these people:
http://www.powerlinecommunications.net/ ... erline.htm

PPL has had running broadband Internet over powerline services in select
markets for a few years now. Some other utilties have similar programs.
http://www.thestreet.com/_tsclsii/tech/ ... 45487.html

Utilities not only have another revenue stream and an efficient Internet
distribution method, but also gain the benefit of a communications channel
to/from their meters.

The ARRL (amateur radio group) has spoken out against some powerline
communications, out of fears that it will cause interference to them.
John
 

Re: Powerline modem

Postby Peter » Wed Feb 09, 2005 3:03 am

The ARRL (amateur radio group) has spoken out against some powerline
communications, out of fears that it will cause interference to them.


Wideband power line systems are effectively wireless systems that use
power lines as a rather crude handrail.
Peter
 

Re: Powerline modem

Postby Ken Smith » Wed Feb 09, 2005 9:43 am

(1) RF transmitter at your meter, "neighborhood" receiver located on a
pole, then connection to phone lines.

(2) Modem connection between your meter and *your* phone line. Power
company polls your modem.

I'll add:

(3) An RF responder that is pinged from a truck going down the street.


I know, some places use this for water meters, but I expect that someone
has done it for power meters.

--
--
kensmith@rahul.net forging knowledge
Ken Smith
 

Re: Powerline modem

Postby James Knott » Wed Feb 09, 2005 2:00 pm

John wrote:

The ARRL (amateur radio group) has spoken out against some powerline
communications, out of fears that it will cause interference to them.

It's more than fears. There have been several documented instances of
interference to radio services. The potenial for interference to the data
communications, from radio transmitters also exists.
James Knott
 

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