HID ADT 31bit

Everything you need to understand HID ADT 31bit

Card format Overview

A proprietary 31-bit card format used in access control systems, featuring a unique structure composed of 4-bit site code and 23-bit card number, allowing for easy management and avoiding card number duplication for secure, contactless access.

HID ADT 31bit format properties

Site Code

4 bits. The facility code range is 0 to 15.

Card Number

23 bits. A unique serial number (0-8,388,607) for each card within that facility code.

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Put in the values for this card format, we'll generate the results in a few different formats.

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The API that turns phones into key fobs.