Simulator allows you test features such as Extra Devices, LCD settings, talking events and a wide variety of settings by using a previous roast to simulate a current roast. For example, if you use talking alarms, you may not get the syntax and other choices correct when setting up your events. With Simulator you can run a test without actually roast.
When you choose Menu>Tools>Simulator a dialog will open to choose a roast. Hit Start and off you go.