User's Manual

AD Plus2.0 User Manual
Page 36 of 66
In alarm recording, recording files generated before alarm triggering are extracted
for event analysis. The parameter value ranges from 1 to 60 minutes and is
defaulted to 15 minutes.
1) In normal video recording, when an alarm is triggered, earlier recording data
with a duration indicated by this parameter is extracted and marked as alarm
recording as well. As shown in the figure below, T1-T3 is a normal recording.
After an alarm is generated at T3, T3, and later period, as well as the duration
between T2 and T3, are marked as alarm recording.
2) If there is no recording ongoing and the pre-recording function is enabled, the
device establishes a pre-recording stream segment upon startup. When an
alarm is triggered at T3, the recording generated between T2 and T3 in the
pre-recording stream segment is marked as alarm recording.
3) When non-alarm recording proves to be I-frame recording: After startup, two
stream segments are established, one is I-frame stream segment and the other is
pre-recording stream segment. When an alarm is triggered, the recording
between T2 and T3 in the pre-recording stream segment is marked as alarm
recording.
5. TF Record Mode: specifies the recording mode of the secondary TF card. It
can be set to Sub-Record, Mirror Record, Alarm Record Backup, or Loop
Recording.
 Sub-Record: stores sub stream recordings in the SD card.
 Mirror Record: uses main stream parameters, and its data includes video
data, log information, and black box data. If the channel of main stream
video is disabled, mirror recording does not apply to this channel.
 Alarm Record Backup: stores recording data only when an alarm is