How do I Only read from TCP/IP listener if there is data?

In my data acquisition software that I've written, I have a TCP/IP listener to occasionally receive messages from Matlab. I only want to do that if there are available bytes to be read. I've thought of setting the mode on the listener to Immediate, but it says in the help that there will still be a timeout error. The main things that I'm looking at are avoiding timeout errors, and I don't want waiting for the message to interfere with the data acquisition.
Thanks,
Alan Stemmons
[email protected]

The data acquisition software is running in Labview, while Matlab is running software to control the antenna position. What I would like to do, is have Matlab send a message when the antenna has arrived at the correct position telling Labview to start acquiring, and then also send a message to Labview telling it when to stop acquiring. In between this time, while labview is acquiring, Matlab will also send messages to Labview telling where the antenna is pointed. An example message would be "Az=180, El=45\n". The purpose for this is to keep a log file of when the antenna moves relative to when data acquisition started. The problem that I've had when I tried doing this with a TCP/IP read block with a short timeout is that the read buffer overruns. Basically, I just have a while loop with a Daqmx read block, then the data from that read block is written to a binary file. In this while loop there is a TCP/IP read block that uses immediate mode with a timeout of 10 ms. It tries comparing the string that is read to "Stop Acquiring\n". That is the condition to terminate the the while loop. I'm not going to worry about the log file until I can actually get it to acquire for the whole time. It would be nice if there was some way to make this interrupt driven, so it would only pay attention to the tcp/ip read block if there was actually data. I'm assuming that's where the problem is, although I might be wrong.
Thank you.

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How do I Only read from TCP/IP listener if there is data?

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