I don't have the cRIO in front of me, but you should be able to connect to code already running on the cRIO to debug it. However, the code in your project MUST be the same at the code in the cRIO, or it won't work. A quick search leads me to these steps:
1. Power up your cRIO/Robot.
2. Open the correct project with your code in it.
3. Open up Robot Main.vi
4. Select Operate->Debug Application or Shared Library.
5. Type in your robot's IP address and click "Refresh"
6. Select the application to debug, which should be Robot Main.vi
7. Click Connect
I think that will work, but I don't have a system to test it on, and I'm not a true Labview guru. I got all that info from this NI page:
http://zone.ni.com/reference/en-XX/h...bug_apps_dlls/
If one of the NI guys comes along and declares the above completely wrong then my apologies for leading you astray.