Skip to main content
All CollectionsAlarmsConfiguration and Setup
Configure a BX21 Wireless Relay
Configure a BX21 Wireless Relay

Learn how to configure the Verkada BX21 wireless relay

Updated over a week ago

The Verkada BX21 wireless relay is a controlled alarm output device that allows customers to connect 12/24 volt sirens, strobes, or other alarm signaling devices.


1. Relay Output (NO, COM, NC)*

2. (Optional) Wired Signal Input (GND, IN)

3. Relay Power Input (GND, 12-24VDC)

4. Test/Pairing Button

  • *12VDC operates at 2.5A Max

  • *24VDC operates at 1.25A Max

Supported devices

Output devices

The BX21 has 1 NO/NC alarm output, with a max power draw of 2.5A. The most common output devices are sirens, bells, and strobe lights that are activated when an alarm is raised.

In Verkada Command, you can select outputs to turn on in response to an alarm. When an alarm is raised, the relay supplies power to those outputs. Multiple output devices can be wired in parallel so that activating a single output can turn on several devices simultaneously.

Signal devices

The BX21 supports 2-wire devices, such as door contacts, that are wired to the input and GND terminal. It does not matter which wire goes into which terminal.

Power devices

The BX21 takes a 12VDC at 2.5A or a 24VDC at 1.25A. This is connected to the GND and 12–24v terminals.

Recommendation. If you use an output device that draws a lot of current, the max amperage power supply should be used to avoid problems.

Add/edit the relay as an output device

When you add a relay to an alarm site, an output is auto configured.

  1. In Verkada Command, go to All Products > Alarms.

  2. Go to your Alarm site settings > Alarm Actions > Wireless Relay Outputs > Add Output.

Configure an input in Command

  1. In Verkada Command, go to All Products > Alarms.

  2. Go to your Alarm site settings > Devices > Add Device > Add Wired Input.

  3. Configure the input and select the appropriate BX21.

Related resources

Need more help? Contact Verkada Support

Did this answer your question?