How do I get log files from a deployed iOS app that didn't crash?

I know it is possible to get crash reports from the appstore client, either with xcode -> organizer -> crash, or tell the client to go to settings -> privacy -> diagnostics.

However, the application did not crash (just hangs) and no crash report is generated. I would like to get the normal console output of the application in order to gather more information. Is there a way to force the log file to be generated either through the iphone settings or by modifying my application?