Specifications

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GLOSSARY OF TERMS
Blooming - The halation and defocusing effect that occurs around the
bright areas of the picture (highlight) whenever there is an increase in
the brightness intensity.
BNC - Video connector, the most commonly used in CCTV.
Bridge - A device that connects two LAN segments together, which may
be of similar or dissimilar types, such as Ethernet and Token Ring.
Broadband - In network engineering terms, this describes transmission
methods where two or more signals share the same carrier.
BS (British Standards) - BS4737 Standards for design, installation and
maintenance of intruder alarm systems prior to the introduction of
EN50131.
BS5750 Internationally recognised quality standard company
management systems.
BS5979 Standards for construction and working of an ARC.
BS6799 Standards for wireless intruder alarm systems.
BS8418:2010 Code of practice for the installing & remote monitoring
of detector activated CCTV sysems.
BSI - British Standards Institute.
BSIA - British Security Industry Association.
Byte - A unit of information, usually shorter than a computer “word”.
Eight-bit bytes are most common. Also called a “character”.
Cable Screen/Shield - A conductor which forms a sheath around one
or more insulated conductors. This reduces the effect of interference
onto the conductors. This shield is usually metallic foil or stranded wire
wrapped around the conductors.
Category 1 through 5 cables - (CAT 1-5) - The following categories are
based on their transmission capacity. Categories 1 through 5e are based
on the TIA/EIA-568 standard.
CAT1 UTP Analogue Voice, CAT2 UTP Digital Voice, 1-Mbps Data. CAT3
UTP, STP 16-Mbps Data. CAT4 UTP, STP 20-Mbps Data. CAT5, 5e UTP STP
100-Mbps Data
CCD (Charged Coupled Device) - A ‘chip’ that performs the same
function as a camera tube.
CCIR (Comite Consultatif International des Radiocommunications) -
The European TV standard 625 lines 50 fields.
CD-ROM (Compact Disk Read-Only Memory) - A compact disk format
used to hold text, graphics and hi-fi stereo in excess of 650 MB of data,
which is equivalent to about 250,000 pages of text or 20,000 medium-
resolution pages
Chrominance (C) - The part of the video signal corresponding to the
colour information.
CIF (Common Intermediate Format) - CIF refers to the analogue video
resolution 352x288 pixels. Also see Resolution.
Client/server - Client/server describes the relationship between two
computer programs in which one program, the client, makes a service
request from another program, the server, which fulfils the request.
CM (Colour Monochrome) - Colour Mono camera with fixed IR cut filter.
CMOS (Complementary Metal Oxide Semiconductor) - A CMOS is a
widely used type of semiconductor that uses both negative and positive
circuits. CMOS chips require less power than chips using just one type
of transistor. CMOS image sensors also allow processing circuits to be
included on the same chip.
C Mount - Long established industrial standard for connecting cameras
and lenses, widely used in the CCTV industry.
Co-Axial Cable - A type of shielded cable capable of carrying a wide
range of frequencies (video or radio) with very low signal loss.
Codec - Codecs are used to convert analogue video and audio signals
into a digital format for transmission. The codec also converts received
digital signals back into analogue format.
Colour Burst - That portion of the composite colour signal, comprising
a few cycles of a sine wave of chrominance sub carrier frequency, which
is used to establish a reference for demodulating the chrominance
signal. Normally approximately 10 cycles of 4.43MHz.
Composite Sync - A signal comprising of both Line and Field sync
pulses but without any video information.
Composite Video - A mixed signal comprised of red, green, blue,
horizontal and vertical retrace. All compiled and sent via one video
signal on one wire to an RCA connector.
Compression - A number of methods to reduce the size of digital
information. See J-PEG, M-PEG and Wavelets.
Conditional Refresh - Technique used in slow and fast scan where only
small screen changes are transmitted. Up to a certain percentage of the
on-screen picture can be updated before a full picture is required.
Contrast Ratio - The ratio between white and black. The larger the
contrast ratio the greater the ability of a projector to show subtle colour
details and tolerate extraneous room light. There are two methods used
by the projection industry:
1) Full On/Off contrast measures the ratio of the light output of an all
white image (full on) and the light output of an all black (full off) image.
2) ANSI contrast is measured with a pattern of 16 alternating black and
white rectangles. The average light output from the white rectangles is
divided by the average light output of the black rectangles to determine
the ANSI contrast ratio.
CPU (Central Processing Unit) - Computer or Control Panel Unit (Alarm).
Crosstalk - An undesired signal that interferes with the desired signal.
CS Mount (Special C Mount) - New standard for connecting cameras
and lenses. It has a shorter penetration into the camera, needed for
many modern CCD designs.
CS to C Mount Adaptor - 5mm spacer ring used to enable the use of C
mount lenses on CS mount cameras.
D1 - D1 refers to the analogue video resolution 720x576 pixels. Also see
Resolution.
Daisychain - To connect devices in a series, one after the other, where
the transmitted signals go to the first device, then to the second and so
on.
Data Cable - Cable used for transmitting low level signals between
system units.
dB (decibel) - A logarithmic unit for comparing two voltages, each 6dB
doubles the voltage.
DD (Direct Drive) - An auto iris lens requiring a DC reference from the
camera rather than the traditional video reference.