Hi,

to answer the question below, more than 1 data source per ip address, 
here's 2 approaches (many more no doubt are possible):

tcp/ip sockets.  Using these, each ip address can be split into 65536 
channels, or sockets, 0 to 65535.  Some of these are already allocated, 
like 25 for mail and 80 for web browsing.  Anything above 1000 should be 
available but check or be alert to something no longer working and try 
another socket number.  These are also what those nasty hacker creatures 
use for sneaking into unprotected pcs. 

You could have 1 socket per sensor.  Under this regime you would need to 
have a server program running in the pc for each socket.  It "listens" 
for incoming connections.  When a connection request is made, it starts 
serving up the stream of data for that particular sensor.

But rather than have 1 sensor on a single socket it is more sensible to 
have many sensors on a single socket using a data protocol.  This is how 
I have designed my system.  It sends out a continuous stream (50 samples 
per second) of "(Lehman reading) (geophone reading) (time stamp)".  My 
graphing program makes a connection to the "data server" and plots the 
values from the 2 sensors as they arrive.  See http://www.iasmith.com.

As you'll see, my above-ground system is badly affected by wind.  I 
recently achieved a big increase in sensitivity and was rewarded by the 
now increased significance of the wind  :-( .  I need to dig down and 
make a below-ground system.  Segway to the next topic...

Cheers

Ian



Jerry Payton wrote:
> Hmmmm  That's interesting, Jon.  I'd like to know more how you 
> accomplish that without a different IP address for each geophone that 
> you use.  You might contact me directly  gpayton880@....... 
>   with an explanation and/or drawing when 
> you have time.
> Regards,
> Jerry
>  
>  
> ----- Original Message -----
> *From:* Jón Frímann 
> *To:* psn-l@.............. 
> *Sent:* Friday, January 04, 2008 11:10 AM
> *Subject:* Re: Hekla volcano geophone planned
>
> Hi
>
> The geophone is going to be located at a house that is ~20 km away from
> Hekla volcano. But the connection from there to my main computer I am
> going to use the internet.
>
> Regards.
> -- 
> Jón Frímann
> http://www.jonfr.com
> http://earthquakes.jonfr.com
> http://www.net303.net
> http://www.mobile-coverage.com/
>
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