# 2804 Wiegand

Everything you need to understand 2804 Wiegand

## Card format Overview

A proprietary 28-bit card format used in access control systems, featuring a unique structure composed of 8-bit facility code and 15-bit card number, and 3 parity bits (even and odd), allowing for easy management and avoiding card number duplication for secure, contactless access.

## 2804 Wiegand format properties

### Facility Code

8 bits. The facility code range is 0 to 255.

### Card Number

15 bits. A unique serial number (0-32,767) for each card within that facility code.

### Even parity

Even Parity for Even parity over bits 1-13.

### Odd parity

Odd Parity for Odd parity over bits 5, 6, 8, 9, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 26, 27.

### Odd parity

Odd Parity for Odd parity over bits 0-26.

### Generate examples

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

#### Here's your example

| Format   | Value                            |
|----------|----------------------------------|
| Hex      | 83200C8<br>Copy                  |
| Decimal  | 137494728<br>Copy                |
| Binary   | 1000001100100000000011001000<br>Copy |

## The API that turns phones into key fobs.