Trigger Alarm Output on Security Camera DVR via Mobile App

Watch this video to see how-to trigger an alarm relay output on a Viewtron security camera DVR using the mobile app for iPhone and mobile app for Android. In this example, we will turn on an alarm strobe light remotely from the iPhone app. Viewtron security camera DVRs and IP camera NVRs have alarm output ports that support integrating external alarm devices such as strobe lights and audio sirens. The alarm devices that connect to these ports can be turned on via alarm triggers that you can setup on the DVR / NVR. For example, you can turn an alarm light on if a person is detected by a security camera in a certain area.

In addition, these devices can be turned on manually using the iPhone app or Android app. This is what I will be covering in this video and article.

Project Setup

You can follow these instructions to setup this project on your Viewtron IP camera system.

DVR / NVR Alarm Relay Output

DVR Alarm Relay Output

Please note that the the alarm strobe light is self powered. The alarm outputs on the DVR / NVR are simple relays (they are either open or closed). They DO NOT provide any power output. Also, please note that you can ONLY connect low voltage devices alarm devices to these alarm relay ports. Connecting high powered devices can fry your motherboard and ruin your DVR / NVR.

Important WARNING! The maximum current rating of these alarm relays is 1A, the voltage is 30VDC/ 250VAC, so the maximum power rating is 30W for DC alarm device, 250W for AC alarm device.

You can see above how I wired the strobe light to the output port. Notice how the strobe light’s 12V DC power supply is connected in-line. I used 18 gauge / 2 conductor power wire to connect the strobe light to the recorder.

DVR NVR Alarm Outputs

Here is a close-up of the alarm output ports on the back of the DVR / NVR. I am using the COM1 and NO1 ports. NO stands for normally open, which means that power does not flow thorough the relay until the alarm is triggered.

Trigger Alarm Output from iPhone App

trigger DVR Alarm output iPhone app

This is how you can manually trigger (turn on) the alarm relay output on the DVR from the iPhone app. Please note that the Android mobile app is identical to the iPhone all in looks and functionality. They are exactly the same app.

  1. Tap the menu icon in the lower right (the icon with the 3 dots…).
  2. Tap Manual Alarm.
  3. Tap the Alarm Output that you want to trigger / enable.

Click here to learn more about the mobile apps and desktop software for Viewtron security camera systems. All applications work with Viewtron DVRs, NVRs, and directly with Viewtron IP cameras. There are additional video demos on that page.

Video Transcript

Hi, everyone. Mike from CCTV Care Pros here. I’ve been doing some testing lately using the alarm outputs on our Viewtron surveillance DVRs and NVRs. In this video, I’m going to show you how you can wire up an external sensor, like a strobe light, and then remotely trigger that device using the Viewtron mobile app for iPhone or Android. So first, I’ll walk you through real quick how to wire it up. And then I’m going to show you on the screen how I trigger it in the app. And I set up one of our Viewtron cube cameras to zero in on the strobe light that I have set up for testing. So you’ll be able to see when I trigger the alarm output on the mobile app, that strobe light will start flashing.

Here’s a close-up view of the alarm input and the alarm output ports on the back of the DVR. And we’re going to be using that alarm output number one. So the ports labeled COM1 and NO1. NO stands for normally opened and COM1 stands for basically common or ground. Normally, open means the circuits open and no power can flow through to it until the alarm is triggered and then it’s closed allowing power to flow through the circuit and the device to be turned on. Here’s how our alarm strobe light is wired to that alarm output port. Notice that the strobe light is self-powered. This is a 12-volt DC power device with its own power supply. These alarm relay output ports on Viewtron DVRs and NVRs, they don’t supply any power to the device. They’re simply closing the circuit and acting as a relay to trigger its own power supply to flow through the circuit.

So now here’s a live view on the DVR. It’s a four camera view. And what I’m going to do is I’m going to put a live view of my iPhone app in the upper left hand corner here. And then, I’m going to switch to the full screen view of the camera that’s monitoring our strobe light. And then, to access the alarm output controls on the app, click the icon lower right, and then select manual alarm, and then tap the icon next to alarm output one, and you’ll see the strobe light will start flashing. That alarm output one just closed that alarm relay circuit, allowing power to flow through, therefore, allowing the strobe light to flash.

I hope this video has been helpful in showing you how to trigger the alarm relay output on Viewtron DVRs and NVRs using the mobile app. If you have any questions about any of this, you can email me anytime at If you want to learn more about our Viewtron DVRs for BNC cameras and NVRs for IP cameras, you can visit Thank you for watching.