Login at Prism Web Application.
Navigate Settings page.
Here you can see list of the cameras with indicators.
The indicator, which is located to the right of the camera name shows the current camera status.
The green light means that camera has online status.Prism is running and receiving data from that camera.
The red indicator means the camera is offline and no data is being received from that particular camera.
Cameras may have offline statuses because of network or hardware issues.
If you hover over the red indicator, you can see how long the given camera has been offline.