Credential scanning readers connect to an access control controller through a wired OSDP or Wiegand interface, which carries credential data from the reader to the controller for authorization. OSDP can support secure communication and multi-drop wiring, while Wiegand provides a traditional reader-to-controller connection for compatible access control systems.

Single-gang credential scanning readers fit standard single-gang electrical boxes and provide a broader face for installations where wall space is available. Mullion credential scanning readers use a narrower housing designed for door frames, narrow mounting areas, or posts, while both form factors may support proximity, high-security, mobile, or keypad credentials depending on the reader.

Credential scanning readers that support proximity, high-security smart credentials, and Bluetooth Low Energy (BLE) mobile credentials can continue reading existing 125 kHz proximity credentials while new encrypted credentials are introduced. This multi-technology approach lets integrators transition access points in stages without requiring an immediate credential replacement across the entire system.

Consider the mounting location, available space, and exposure to dust, rain, or vandalism: single-gang readers suit standard wall boxes, while mullion and ruggedized housings support narrower or more demanding installations. For high-traffic entries, choose a reader that supports the credentials in use, such as proximity, high-security smart credentials, Bluetooth mobile credentials, or PINs, and confirm whether the system uses OSDP or Wiegand wiring.