How to enter the library and contact the person in charge directly when the access control system of the library fails. The access control system of libraries in Wangcheng and Kaiyuan campuses can't operate normally due to the failure of the front-end server of the card. If it is the peak time for students to enter the library after class every day, the library should take turns to send teachers to guide and supervise students to enter the library through the access control system. This will not only avoid omissions.