Specifications

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GLOSSARY OF TERMS
Format - How the computer arranges the information onto disk. Can
also apply to printers.
Frame - One complete TV picture made up of approximately 625 lines.
25 frames are transmitted every second.
Frame Store - Digital information store capable of holding a complete
frame of video information.
Frame Transfer CCD - Type of CCD chip which consists of vertical
charge transfer channels placed side by side. During vertical blanking,
the charge generated in the light sensitive imaging area is rapidly
transferred into a shielded storage area. During the horizontal blanking,
this charge is shifted down a line at a time into a horizontal shift register
where it is clocked out during each line period to form the video signal.
Frequency - A unit of measurement for electrical signals.
FSK - Frequency Shifted Keying a form of signaling employed by some
coaxial born telemetry equipment.
FTP (File Transfer Protocol) - FTP is an application protocol that uses
the TCP/IP protocols used to exchange files between computers/devices
on networks.
Full Picture Update - The technology which enables a transmission
system to update a high quality full picture on each picture refresh at
very fast speeds.
Galvanometric (Galvometric) - One method of converting the small
electric currents produced by Auto Iris circuits into physical movement
of the iris diaphragm. Used in both Auto Iris and Direct Drive lenses.
Gamma - A camera adjustment that ensures a linear correlation of light
gain on the entire system e.g. a doubling of light input gives double light
output.
Gateway - A gateway is a point in a network that acts as an entry point
to another network.
Gen. Lock (see Ext. Sync) - To synchronize one piece of equipment to
the sync pulses of another.
Ghost - A shadowy or weak image in the received picture, offset to
either the right or to the left of the primary image.
Gigabit Ethernet - Technology that adapts the Ethernet model for data
transmission at 1 Gbps or higher.
Gigabyte (GB) - Order of magnitude; 109
GPRS - General Packet Radio Service.
GPS - Global Positioning System.
Ground Loop - An unwanted continuous or temporary ground current
flowing back and forth between two devices that are at different ground
potentials.
GSM - Global System for Mobile communications.
H.264 - H.264 is a standard for video compression. It provides quality
video at lower bit rates than some other video compression methods.
Hard Disk - Non volatile digital data storage device used in PCs. Come in
various storage sizes, normally measured in GB. See Hard Disk Recorder.
Hard Disk Recorder – HDR (Digital Video Recorder - DVR) - Device
that uses digital techniques to record CCTV pictures to a hard disk. The
results can be of higher quality than VHS or SVHS; events can be found
faster and there is no loss of quality when copies are made.
Hardwired - Method of controlling camera points using multi core cable.
Horizontal Resolution - The maximum number of individual picture
elements that can be distinguished in a single scanning line.
Hot Swapping - Removing and replacing a component of a larger
system while the system is receiving power and operating.
HSBLC (Highlight Suppression Back Light Compensation) - An
electronic circuit that turns any white part of a video signal, over a
preset level, to black. If installed in the auto iris video line it decreases
the contrast of one picture, bringing out detail otherwise lost in shadow.
HTML (Hypertext Mark-up Language) - A standard for defining
documents with hypertext links. HTML is a subset of SGML (Standard
Generalised Mark-up Language) and is used to establish links between
documents on the World Wide Web.
HTTP (Hypertext Transfer Protocol) - The clients/server protocol used
for connections to servers on the World Wide Web. Addresses of Web
sites begin with an http:// prefix.
Hub - A central connecting device in a network that joins
communications lines together in a star configuration.
Hum - Electrical disturbance at the power supply frequency or
harmonics thereof.
Hz (Hertz) - Cycles per second.
Ident - Number or title super-imposed on a video signal.
Image Burn (Retained Image) - A change produced in or on the target
of the pickup device which remains after the removal of a previously
stationary light image.
Image compression - Image compression minimises the file size (in
bytes) of an image.
Image Sensor Format - Size of the CCD element in the camera.
Impedance - The effective resistance of an electronic circuit to an A.C.
signal.
Interlace (2:1 Interlace) - The accurate combining of two fields, one odd
one even, into a single frame.
Interleaving - Method used with alarms or activity detection which
allows extra frames of video from alarmed cameras to be added to a
time multiplexed sequence whilst a state of alarm exists.
Interline Transfer CCD - Type of CCD chip in which the photosensors
acquire and store an electric charge according to the intensity of light
falling on them. The charges are first transferred to a vertical shift
register and then a horizontal shift register. This is controlled by an
external pulse timing system.
Internal Sync (crystal controlled) - A camera that generates its sync
pulses without reference to any other source. Normally using a crystal
controlled oscillator.
Internet - Any large network made up of several smaller networks.
A group of networks that are interconnected so that they appear to
be one continuous large network and can be addressed seamlessly
at the OSI Network layer through routers. The industry name for the
Worldwide interconnected network. Based upon the original ARPANET
network, it’s used as a reference resource, a way of sending e-mail and
an online chat room for users around the world.