Unlike master readers, “slave” readers are unintelligent card readers that must consult their master reader to grant or deny access to a space. They do not contain their own databases and, therefore, must be connected to a master reader to be effective. Each pair can only contain one or each unit, ensuring that signals do not get crossed between multiple masters or “slaves.” They are also sometimes referred to as “dumb” readers. The units can commune through either wired or wireless connections, which makes setup easier and keeps access time as low as possible. Before any cards work at the “slave” readers, cardholders must use their access credentials at the associated master readers, which ensures that their specific information will be entered into the independent master database. This feature is ideal at security checkpoints of high importance or in places that are physically removed from the rest of your space, including parking lots and front desks, and is easily combined with other security measures like video verification and signature tablets.