You should become familiar with the beep and light codes if you are a happy owner of an iRobot Roomba 500 series robot. Sometimes your tough dirt fighter will get stuck in corner and will talk to you in its "beep" and/or "light" language to help him out from a situation. Some of you may learn the 500 series "Beep" and "Light" language but I post a translation chart for the few of us who are unable to memorize it or do not wish to do so. The 500 series is the first iRobot robot floor cleaner that has some "human language" error messages but the rest are still "legacy" beep and light code language. Hope this helps you to help your little robot friend from certain problems.