Videoswitch VDM - Manual (Page 50)

Videoswitch
VDM Digital Recorder
Vdm601t.doc
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Notes:
The Relay Hold Timer extends the time for which the Alarm/Activity recording mode is applied.
Any cameras which do not have video are automatically excluded even if specified in any of the camera
select lists.
10.4.3.3.5 Storage Allocation (%)
An allocation may be made here for reserving disc space for alarm and activities. This enables the automatic
Image Retention calculator to make an allowance for alarms. The higher the percentage that is set, the
lower the update rate will be for Normal recording.
If this setting is lower than required for the actual alarm activity, the image retention period will be reduced. If
set higher than necessary, the update rate will be reduced.
As the amount of alarms cannot be known in advance, a suitable estimate must be made for this setting.
10.4.3.4 Record Options
10.4.3.4.1 Recording Enabled
Recording may be disabled by setting this option to NO. This should be done if a VDM is used solely to play
back hard drives from another location. Also if evidence of a serious crime has been recorded, it may be
prudent to disable recording to ensure that over-writing cannot occur until all necessary evidence has been
removed.
10.4.3.4.2 Image Size Control
This option determines how the size of images is calculated by the VDM.
• If set to Fixed image size, the VDM will force the image size to a fixed value, depending on the
quality setting for the camera and recording mode.
• If set to Variable image size, the VDM will adjust the image according to the content of the image.
The quality setting limits the maximum size of the image. Images with high information content will
be larger (more Kbytes) than images with lower information content. This is the preferred mode of
operation as it maximises the utilisation of the hard drives. Space is not wasted, for example, on
nighttime images where there is little detail, or images of nearly empty rooms. When lights are
turned on, or if people come into the room, the image size will automatically rise to record the
increased amount of information.
10.4.3.4.3 Record Drives
This specifies the drive or drives to be used for recording. The normally setting is “Alternate 1 and 2“ (even if
only one drive is actually fitted).
10.4.3.4.4 Drive Full Options
When a drive becomes full, recording can be set to stop. Normally the Auto setting is used, where the hard
drives are continuously re-written after the image retention period has expired.
10.4.4 Activity/Alarms
10.4.4.1 Activity Detection
Activity detection may be set for each camera. Use the up/down keys to highlight the part you want to
change, and the camera keys to make the changes.
If the top row is highlighted in red, you can set the sensitivity and pixel count as follows:
• Use cameras keys 1 to 8 to set the sensitivity of the zones. The same sensitivity applies to all zones
that are enabled. A higher number means greater sensitivity. A typical setting would be around 5 or
6.
• The pixel count is set using camera keys 9 to 16. The pixel count indicates how many zones have to
be active before detection occurs. A typical setting is 3 or 4. A higher the pixel setting reduces the
instances of false alarms, but also means that large changes are required to trigger detection
If other rows are highlighted in red, you can set specific zones. Each row has 16 zones, and the camera
keys 1 to 16 are used to turn these on or off. A plus (+) indicates a particular zone is enabled. If it is enabled
and detecting activity, a white block will appear instead of the plus sign.