following recording search menu
2.4.1Alarm setup
Alarm parameter
【Disk Invalid】when video storage fails, whether the alarm information occur. On/Off switch.
ON---Enable alarm input; OFF---Disable alarm input. Press【OK】to select.
【Space Unavailable】alarm information occurs when room for video storage is less than a
certain capacity and cycling record is “OFF”. Press【OK】to select.
【Video Lost】 ON---Enable alarm recording; OFF---Disable alarm recording. Press 【OK】
to select.