Summarize the following:
Add 1 cup (225 ml) farro and 3 cups (750 ml) water to the rice cooker and cook for roughly 45 minutes.  Use soaked whole-grain farro. The farro should be soaked overnight for at least 8 hours. Set the time manually to 45 minutes. If your rice cooker has optimized settings for various types of grains or rice, use the "Brown Rice" setting. Use 1 cup (225 ml) farro and 3 cups (750 ml) water and cook for 10 to 15 minutes.  You do not need to soak the farro for this method since it will cook in roughly the same amount of time either way. Cook the farro for two to three whistles.

Summary:
Cook the farro in a rice cooker. Prepare the farro in a pressure cooker.