1, the video loss alarm is turned on, and now there is video loss. Generally, it is not opened by default.
2. When the motion detection alarm is turned on, the object in the picture will give an alarm when it changes or moves, and it is generally not turned on by default.
3. Hard disk error alarm, hard disk error, the host sends out an alarm sound prompt, which is usually turned on by default, which is probably a hard disk error. Please check the hard disk management option or storage device option in the suggestion menu.