Dedicated Micros ECO 9 Guide D'installation page 7

• When connecting the Eco9 to a branch circuit this must be rated 15Amps.
• It is recommended that a UPS (Un-interruptible Power Supply) be
connected to the unit in case of power failure. This will ensure the
continuous operation of the Eco9.
A quick overview of digital recording
Digital multiplex recorders work in exactly the same way as analogue
multiplexers except that they use hard disks to store video, instead of VCR
tapes. Analogue recording uses time-lapse recording to extend the length of
time recorded onto 2 or 3-hour tape - recording fewer pictures every second.
Adjusting the number of pictures recorded every second also extends the
length of time recorded onto the hard disk of a Eco9. However, other factors
also determine the amount of time that can be stored on the disk of a digital
multiplex recorder:
• The image quality
• The record rate
• The hard disk capacity
Image quality
Digital multiplex recorders store images in a compressed format, allowing
images to be recorded more efficiently. The higher the compression, the
smaller the file size, but the image quality will suffer. Eco9 can compress
images between 6KB and 45KB.
Kilobytes and Gigabytes are units of storage:
1GB = 1024 Megabytes (MB)
1MB = 1024 Kilobytes (KB)
With analogue recording, the image quality is dependent on the type of VCR
being used; VHS or S-VHS. Eco9 allows the image quality to be altered by
adjusting the image size, for example, Low quality is 14KB, Medium is 18KB,
and High is 25KB*.
Using a larger image size will fill the hard disk faster than a smaller image size,
as more space is required to store it. To achieve the same amount of recording
time when a larger image size is used requires the record rate (PPS) to be
reduced.
* Note that as for all digital recording, image quality can vary for different scene types, Medium quality
may be 18KB in one scene, but it may be 30KB or more to get the same quality in a scene with
more detail.
Record rate
The record rate is the amount of pictures recorded to disk in a second, or
pictures per second (PPS). This is a system wide figure, so whether 1 or 9
cameras are recorded, the record rate remains the same. The update rate per
camera can be worked out using the record rate:
Update rate = No. of cameras
Record rate
Calculating recording time
Eco9 calculates the recording time automatically when the record rate and
image quality are entered. Alternatively, an interactive record calculator is
available for download from our web site:
www.dedicatedmicros.com
5