Module 2 / Lesson 2
How Readers Interpret Credentials
1 min read
A reader captures credential data at the door and forwards it to a controller, which makes the actual decision.
What happens at the reader
- The credential is presented (tapped, swiped, or scanned)
- The reader reads the raw data and converts it to a standard format
- The data travels to the controller over a wiring protocol
- The controller looks up the credential and decides grant or deny
How readers differ
- Frequency — 125 kHz proximity vs. 13.56 MHz smart cards
- Protocol — legacy Wiegand vs. the secure, supervised OSDP
- Encryption — whether the card-to-reader exchange is protected
- Extras — keypads for PINs, or biometric sensors
The flow, step by step
Rendering diagram...
Prefer OSDP over Wiegand for new installs: it supports encryption and detects tampering or cut wires.