i am trying to send a wireless signal from three different point to a central receiving point, then depending on which signal is received 1,2, or 3 send data to a website using the Ethernet shield. My question is what do i need to for this project exactly or if anyone has any better ideas. i was thinking of using 4 xbee modules 3 just for transmitting and 1 for receiving that would be connected to the Ethernet shield and arduino.
Thank you in advance.
You didn't mention what kind of data you are sending but four XBees should work
and should be fairly easy to implement. Hopefully you could set up the three to
run standalone.
(* jcl *)
it's a RF signal
basically each xbee is located on a transformer, when any of the three transformers has a fault, the corresponding xbee module should send a signal to the central receiving point (the ethernet and the arduino) and from there we can get to the internet and be notified that this specific transformer is having a fault
Most wireless signals are RF 
But the question was what kind of data are you sending? Are you running code on the
XBee to periodically monitor the digital or analog lines and then transmit? Are
the XBees just periodically transmitting?
XBees are versatile so you probably won't have a problem.
(* jcl *)
I replied too quickly
That sounds like a perfect application for XBee's if the transformer
does not interfere with the XBee transmission. How big is the transformer?
Is it shielded?
You may want to evaluate the different antenna options for the XBee. You can get
the XBee with a co-ax connector and a whip antenna. This may help you in
packaging the radio.
(* jcl *)
it is just going to send in case of fault occurrence. well our transformers are old fashioned ones, we have a flag or you can call it a switch, whenever the fault happens the flag goes on, and we are going to use this flag to trigger our xbee, so basically it's like a digital signal, when the flag is down, don't send, when it's up it will send
Should work well.
Rather than only sending when the flag is up I would periodically send when
the flag is down too. That way you could detect if the radio is functional by
sending out a "heartbeat".
(* jcl *)
Thank you so much for your help man
i have another question if you are still there, can i use a xbee shield and an Ethernet shield with the same arduino board ?
I'm still here but I have never used an Arduino I make my own boards (www.wiblocks.com). You may want to start a separate thread.
If there is a PC near the receiver XBee you just connect the XBee to a USB port.
I did a little XBee server (XBeeSRV) using a TCP/IP socket. The main program opens a
socket to XBeeSRV to send and receive ASCII strings. I then wrote a little web server
that opens a socket to XBeeSRV so strings could be transmitted and received
using a webpage.
Once I get my XBee nodes out I will place these examples on my site.
(* jcl *)