# PointGaurd MDI 37bit

Everything you need to understand PointGaurd MDI 37bit

## Card format Overview

A proprietary 37-bit card format used in access control systems, featuring a unique structure composed of 4-bit site code and 29-bit card number, and 2 parity bits (even and odd), allowing for easy management and avoiding card number duplication for secure, contactless access.

## PointGaurd MDI 37bit format properties

### Site Code

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

### Card Number

29 bits. A unique serial number (0-536,870,911) for each card within that facility code.

### Even parity

Even Parity for Even parity over bits 1-18.

### Odd parity

Odd Parity for Odd parity over bits 18-36.

### 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 | 3C00000C8<br>Copy |
| Decimal | 16106127560<br>Copy |
| Binary | 0001111000000000000000000000011001000<br>Copy |

## The API that turns phones into key fobs.

[Get started](/content/signup/index.html)