Alarm Record Mode; Alarm Record Rate - American Dynamics EDVR Installation And Operation Manual

EDVR Installation and Operation Guide
2. Disk - Full Alert
This signals a disk is fully recorded. The options are On and Off.
On: Enable the function.
Off: Disable the function.
3. Pre-alarm
This option determines that images prior to an alarm will be recorded in the hard disk drive. When an alarm is
triggered the device will record the images prior to the alarm for 10 seconds.
ON: Enable the function.
OFF: Disable the function.

4. Alarm Record Rate

For an NTSC (video output) configuration, the speed can be set from 1 to 60 IPS. For a PAL configuration, the
speed can be set from 1 to 50 IPS. When any Camera's alarm happens, the EDVR's Record Rate changes to the
Alarm Record Rate. Normally, the Alarm Record Rate's setting value will be greater than the Normal Record
Rate's setting value for higher performance demand during alarm. Because the Record Rate in general is an
aggregate rate of the system, whenever a rate (regular or alarm rate) is in effect it is shared (not necessarily
equally) by all cameras that are being recorded at the time. The only exceptions to this general rule are the
extreme cases to be discussed below under Exclusive mode. During alarm, some cameras may achieve higher
record rates than others due to a preferential recording sequence determined by the Alarm Record Mode of the
alarm cameras with the constraint that 30 IPS for NTSC and 25 IPS for PAL is the limit for any single camera.
Note
F/S and IPS are used interchangeably for images per second as images are not interlaced.

5. Alarm Record Mode

The recorded images of strategically - located cameras must be greater in number when an alarm sensor or
motion detection is activated. Each camera is provided with four levels of alarm record Mode: Exclusive,
Interleaved, Double, and Normal. The recording priority follows the order as listed with the allowance that
Exclusive is absolute. Non-alarmed cameras are at the same priority level of alarmed cameras of Normal Alarm
Record Mode. The Alarm Record Mode settings determine the preferential recording sequence of all cameras as
guided by the following rules:
Exclusive
If an alarm is activated in a channel of this setting, the EDVR will change the recording rate to the Alarm
Record Rate set for this channel and will only record the cameras set to "Exclusive" and are alarmed at the
time. No other camera will be recorded. The usual limitation of 30 IPS per channel for NTSC and 25 for PAL
applies. The extreme cases alluded to before happen when alarm is triggered in more than one camera of
this mode. In this case, each of the "Exclusive" cameras will be recorded at the same rate. The system will
attempt to apply the highest "Alarm Record Rate" set among the "Exclusive" alarm cameras, only to be
confined by the system total and the usual limit of 30 IPS for NTSC and 25 for PAL. The end result is a
record rate equaling the highest "Alarm Record Rate" set among the "Exclusive" alarm cameras, 60 divided
by the number of "Exclusive" alarm cameras, or the usual limit (30 for NTSC and 25 for PAL), whichever is
the lowest.
Example
There are three "Exclusive" cameras in alarm. If the Alarm Record Rate is set to 60 IPS then each camera
will receive 20 IPS. This is because the total number of IPS available is limited at 60 IPS. For the same
reason, if the Alarm Record Rate is set to 40 IPS each will still be getting 20 IPS. However, if the Alarm
Record Rate is set to 15 IPS, then each will receive 15 IPS, because the total number of IPS desired is
less than 60 IPS.
From the example above we can see the deviation from the general rule that the record rate is an aggregate
rate. In the first case, the record rate happens to be the aggregate rate of all three cameras being recorded.
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