Three. According to the data of the intelligent book returning machine, three output point addresses are used. Intelligent book returning machine is a smart cabinet product that can borrow and return books 24 hours a day. This is a new product. Readers borrowing and returning books by themselves will help the library to improve the circulation rate of books, simplify the process of borrowing and returning, and facilitate readers to complete borrowing and returning quickly and accurately under the condition of limited human resources.