Re: No communication?
 

If it worked completely fine, then the code must have been built and sent to the cRIO at some point. If the "Always run deployed code on startup" option was checked when the cRIO was imaged the first time, either "Deploy" or "Run as startup" would have worked, but it's good practice always to use "Run as startup" just to remove one potential point of confusion.

When you reimage the cRIO, the process erases any previously deployed code. You don't need to build the project again unless you've made changes, but you do need to put the built code into the cRIO's filesystem. The simplest way to do that is to use the "Run as startup" menu command.