Glossary

■Glossary

• I/O terminals

Terms used for referring to both input and output.

• RS-232C

Connection standard used for handling data between devices such as a PC, modem, etc. A standard when connecting a PC and modem. The upper limit for the communication speed of this standard is 115.2 kbps and the maximum transfer distance is 15 m. Since this standard only defines the roles and physical characteristics of the connector 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 process as tapes and is used in PCs. An aluminium disk coated with magnetic materials is used on the surface as the storage 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.

• 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.

■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.)

Recording interval

of camera

 

1 second

 

 

 

 

 

C4-2

 

 

 

 

 

 

 

 

 

 

1 second

 

 

 

C3-2

 

 

C2-2

 

 

C1-2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C4-1

C3-1

C2-1

C1-1

25P

C1-3

25P 12:00:03~

25P

12:00:02~

Examples of time displayed

 

during playback.

12:00:01~

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••Glossary

82