# Badge Reader Support

Verkada’s access control system supports the popular Wiegand protocol for badge readers which encompasses most of the Human Interface Device (HID) and similar readers deployed today. Verkada also supports Open Supervised Device Protocol (OSDP) through Verkada and third-party badge readers.

{% hint style="warning" %}
The AC41 does not support voltage above 7V on the D0/D1 ports.
{% endhint %}

## How it works

### Wiegand

Wiegand badge readers generally have 6 outputs:

* \+ (Positive)
* \- (Negative)
* D0
* D1
* RLED
* GLED

Each of these outputs has a corresponding input on each [AC41](https://docs.verkada.com/docs/door-controller-ac41-datasheet.pdf) door cartridge, as shown in the highlighted section of this door cartridge diagram. Each input has its label directly to the left.

### OSDP

OSDP badge readers have 4 outputs:

* \+ (Positive)
* \- (Negative)
* A
* B

Similar to Wiegand, each of these outputs has a corresponding input on each AC41 door cartridge, as shown in the highlighted section of this door cartridge diagram. Each input has its label to the left of the Wiegand labels.

Once [wired](/access-control/configuration/configure-a-door-in-command/wire-a-door-to-an-ac41-cassette.md), the badge reader is ready to go and you only need to activate the [door cassette](/access-control/configuration/configure-a-door-in-command.md) in Command to have it running alongside your other readers.


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