# Use the AC41 Test Buttons

The Verkada [AC41 4-Door Controller](https://docs.verkada.com/docs/door-controller-ac41-datasheet.pdf) has 4 buttons to help test or emulate different events. Test buttons help you test the relays of the controllers and the request-to-exit (REX) and door position indicator (DPI) inputs on the individual ports.

{% hint style="danger" %}
The controller needs internet access for the test buttons to operate.
{% endhint %}

***

## Door button

{% stepper %}
{% step %}
**Press the DOOR button to cycle which door is selected for testing. The selected door has its corresponding LED turned on. For example, if door 2 is selected, the LED under 2 would be on.**
{% endstep %}

{% step %}
**Once you select a door, the 3 LEDs indicate the status of the circuit, as shown below.**

<div align="left" data-with-frame="true"><img src="/files/ltKiSi37VXm8iXyXsvhj" alt=""></div>
{% endstep %}
{% endstepper %}

## Trigger Lock button

When the LED is on, it indicates that the lock is locked. When the LED is off, the lock is unlocked.

<div data-with-frame="true"><img src="/files/fd7lwivYljr53Kod8vM9" alt=""></div>

## Emulate DPI button

When the door is closed, the LED is on, indicating that the circuit is complete. If the door is open, the circuit is open (the LED is off).

<div align="left" data-with-frame="true"><img src="/files/POefTzNsa0bBglhNDlhR" alt=""></div>

## EMULATE REX button

When the **EMULATE REX** button is triggered, the circuit is complete (the LED is on). In the resting state, if no one is detected by the REX, then the LED is off.

<div data-with-frame="true"><img src="/files/YmmEeEmuThn0HVmpDAHd" alt=""></div>

When you press and hold the **EMULATE REX** button, the controller switches the current state of the DPI or REX.

**Example**

If the DPI LED is on, it means the door is closed. If the **EMULATE REX** button is pressed, the LED turns off (the door is open).

<div data-with-frame="true"><img src="/files/CBbD3DNfL7GoHbwWXlij" alt=""></div>


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