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We're attempting to network between an iphone and a computer (windows 7) using TCP/IP over Wifi. We are having a lot of difficulty setting up this basic network and we were hoping to get some guidance.

Server side:

Currently, we are trying to use MATLAB's tcpip protocol to set up the connection on the computer. We have determined the IP addresses of the phone and the computer and we picked a port number (501), that we are trying to read and write from. We allowed that port number in windows firewall.

In simulink we set up a TCP/IP send block to send out a constant, by double-clicking on that block and selecting the "verify address and port connectivity" button we get the error message:

"The remote address '140.180.....' has been found. However, we are unable to connect to the server at the specified port.

Specify a different port or wait for the current port to become available"

We have tried other port numbers, but gotten the same message.

We have tried using an ad hoc connection between the computer and the iphone to the same effect.

We have also tried other MATLAB scripts to set up the connection (e.g. http://www.mathworks.com/matlabcentral/fileexchange/24524) but we always get and error in the connection

Finally, we tried sending and receiving info over TCP/IP with the same computer using two MATLAB instances running in parallel, but we generally get the same error message.

We even tried UDP...no dice.

Client side (iphone)

We're using NSStream exactly as per this tutorial: http://www.devx.com/wireless/Article/43551/1954

The stream is opened upon a toggle action, and we immediately send a string to the server. We also tried sending a continuous sequence of data with the run loop. One strange bit of behavior is that, after the stream is open for a little while (~1 min), the handleEvent method does seem to get triggered (implying something is received from the server??) because we get a log message corresponding to case NSStreamEventErrorOccurred.

We think the issue lies on the server side, but really don't know enough to be sure or to debug properly. Any help would be very much appreciated.

G.S.
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  • Can't answer the question but I'm very interested in what you're trying to achieve? – simonmorley Mar 09 '12 at 18:51
  • Have you tried hooking a protocol analyzer like Wire Shark http://www.wireshark.org/ to see that the packets you are actually generating are the packets you expect to generate? From the fact that two matlab scripts can't talk says that something is either fundamentally wrong with how you are doing you networking or your understanding of what is meant to happen. – Peter M Mar 09 '12 at 19:14

1 Answers1

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A long overdue answer to this one: don't network with Windows. We eventually thought to switch over to a mac and lo and behold everything worked properly.

G.S.
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