Product guide

71
Sales: [phone] Technical: [phone] Accounts: [phone]
Glossary of T
er
ms
Lens Calculator Wheel
Used for calculating a lens size or distance fr
om a camera to the
subject.
Line Amplifier (V
ideo line corrector)
A device to make good the loss of signal strength and quality due to
long cable runs.
Line Fed Camera
A camera that r
eceives its power along the same cable that is used
to send its picture back to the monitor.
Line Lock
T
o synchronize the field sync pulses, of an AC powered camera, to the
frequency of the voltage input (line voltage).
Linux
A fr
eeware, clone version of the UNIX‚ System V release 3.0 kernel that
runs on PC x86 machines and other platfor
ms.
Local Ar
ea Network (LAN)
A data-communications system confined to a limited geographic
ar
ea (up to about 10km) with moderate to high data rates (100 kbps
to 100 Mbps). The area served may consist of a single building, a
cluster of buildings or a campus-type arrangement. The network uses
some type of switching technology and does not use common carrier
circuits (although it may have gateways or bridges to other public or
private networks).
Looping
V
ideo input of a piece of video equipment both unterminated and
including the relevant sockets for the extra coaxial cables.
Luminance (Y)
The part of a video signal that consists of the monochrome data.
Lux
Metric measur
e of the light striking a surface. The light available from
that surface will depend on how reflective it is.
M-PEG
Moving Picture Expert Group. A suite of digital compression tools
specifically designed to video images.
Macro
Feature allowing you to pre-programme frequent system
configurations for selection by a single keystroke or optionally by
alar
m inputs.
Matrix Switcher
A switcher able to route any of its camera inputs to any of its monitor
outputs; a name usually reserved for large systems, that often includes
telemetry contr
ol.
Mb
Megabyte, or one million bytes or characters of infor
mation.
Mechanical Focus (Back-focus,racking)
The mechanical aligning of the imaging device with the focal point
of the lens; most important on zoom lenses to ensure the image stays
in focus throughout the zoom range.
Microwave
Radio frequencies between 1 - 30 GHz used for video transmission
over medium/long distance.
Modem
Used with PSTN telephone lines to connect a fastscan system to the
dial up BT network.
Modem
Modulator/demodulator used in data transmission.
Modem (Modulator
-Demodulator)
A device used to convert serial digital data fr
om a transmitting
terminal to an analogue signal (carrier) for transmission over a
telephone channel or to r
econvert the transmitted analogue signal to
serial digital data for acceptance by a receiving terminal.
P
.A.L. (Phase Alternate Line. See CCIR)
Colour TV system used in the UK
PCI‚ (Peripheral Component Interconnect) Bus
PCI Local Bus is a high-per
formance bus that provides a processor-
independent data path between the CPU and high-speed
peripherals. PCI is a r
obust interconnect mechanism designed
specifically to accommodate multiple high-per
formance peripherals
for graphics, full-motion video, SCSI and LANs.
PCMCIA (Personal Computer Memory Card International Association)
A non-pr
ofit trade association founded in 1989 to standardise a
method for connecting peripherals to PCs. PCMCIA cr
eated a 16- bit
socket that's "Plug-and-Play" compatible and can be automatically
configur
ed by a software driver called PCMCIA Card Services.
Peak White Inverter (Eclipser)
An electronic circuit that turns any white part of a video signal, over
a pr
eset 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.
Peer
-to-Peer
Communications in which both sides have equal r
esponsibility for
initiating, maintaining and terminating the session.
Phase Adjustable (see line lock)
The ability to delay the line locking pr
ocess, so as to align cameras fed
from A.C. voltages on different phases.
Photocell
Automatically switches on the infra-red lights when light levels fall to a
pr
eset level.
PING (Packet InterNet Groper)
A utility used to determine if a TCP/IP device is available and
responsive on a network or at an Internet site.
Plasma
A type of flat screen display.
Port
That portion of a computer through which a peripheral device may
communicate.
PPP (Point-To-Point Pr
otocol)
A data-link protocol that provides dialup access over serial lines by
encapsulating protocols in specialised Network Control Protocol
packets. These packets can be used to replace a network adaptor
driver which allows remote users to log on to the network as if they
wer
e in-house.
Presets
The pr
e-positioning of pan, tilt and zoom cameras by the use of
potentiometers in the moving parts of the camera head. These allow
the control equipment to store and move to a set reference point
when the controller dictates or when an alarm exists. Special
telemetry equipment is required.
Pr
otocol
A standard for sending coded messages between computers and
peripherals.
Pr
otocol Converter
Data transmission converter i.e. RS232 to RS485 or vice versa.
PSU
Power supply unit.
Remote Access
The ability of a computer in one location to connect to a device at
another location or site.
Router
A system that stores and forwards data packets- by way of network
addresses- from one LAN to WAN to another.