How do I receive UDP data on Connect ME 9210

I am trying to implement a similar thing to the Digi Device Discovery, and so am sending my Digi module a UDP packet. I have opened a port on my Digi device to listen for UDP data on the port number I am sending on, but how do I actually see any data that is received?

I’ve done similar things with TCP, and use the “recv” command to receive data. But this doesn’t seem to be working with UDP. Any clues gratefully received.

One example can be found here:
also any socket UDP example on the web should work
see this for example