Access control field panels (also known as "Intelligent Controllers") are installed in each building where access control is to be provided. Card readers, electric lock hardware, and other access control devices are all connected to the access control field panels. The access control field panels are used to process access control activity at the building level. The number of access control field panels to be provided in each building depends on the number of doors to be controlled. Access control field panels are usually installed in telephone, electrical, or communications closets.