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•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Glossary
Glossary
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Glossary
• I/O terminals
Terms used for referring to both input and output.
• RS-232C
Connection standard used for handling data between de-
vices such as a PC, modem, etc. A standard when con-
necting a PC and modem. The upper limit for the commu-
nication speed of this standard is 115.2 kbps and the maxi-
mum transfer distance is 15 m. Since this standard only
defines the roles and physical characteristics of the con-
nector pins, there are various types of connectors such as
25-pin, D-sub, etc.
• Hard disk drive (HDD)
Storage device using the same magnetic recording proc-
ess as tapes and is used in PCs. An aluminium disk coated
with magnetic materials is used on the surface as the stor-
age medium and since there is no contact during record-
ing/playback, there is no head wear. Data search is also
quick since recording is performed in numbered sections
called sectors.
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Relation of recording operation to the number of cameras and recording interval settings
The recording pattern of this unit is as illustrated in the diagram below. Image data input from all the connected cameras
is recorded sequentially at a rate of [number of cameras x recording interval]. (25P recording interval during normal
recording.)
C4-2
C3-2
C2-2
C1-2
C4-1
C3-1
C2-1
C1-1
25P
1 second
1 second
12:00:01~
12:00:02~
12:00:03~
C1-3
Recording interval
of camera
Examples of time displayed
during playback.
25P
25P
• Mirroring
One way of protecting data on magnetic disks. This function
writes data alternately to 2 Hard disk drives with the same
capacity. However, there is the demerit of using 2 drives in
place of 1, resulting in half the available space.
• Capacity
Term to indicate the amount of data that can be stored in a
storage device such as memory, disk, etc., and unit is
indicated in B (bytes).
• Partition
A partition is one of the many divided areas on the Hard
Disk.
