Xvision X4/8/16D User Manual V1.1 374-8.3 BUZZER & RELAY SETUPItem DescriptionKey Tone Enable/Disable keystrokes.Buzzer Enable/Disable buzzer operation when the alarm is triggered forsensor, motion and vloss (Video Loss).Relay Enable/Disable the signal to be sent to the RELAY OUT blockswhen the alarm is triggered for sensor, motion and vloss.