No signal alarm Watchdog can alert you by email or phone when it detects there is no signal from the camera. For example, Watchdog can alert you when a camera's video cable or power cable is cut. (Please note USB cameras are not supported. However, this feature may work with most of the USB video capture boxes.) To enable signal lost detection, Click on Setup button Go to the Alarm tab. Check No signal alarm box. Watchdog will perform the operations defined in Alarm setup when it detects no video signal. You can disconnect the cable to test it. Click Setup will stop playing the alarm or the operations defined in Alarm setup when signal lost detected.