1 CCTV SYSTEMS Analog CCTV systems. 2 CCTV SYSTEMS Analog CCTV systems are still prevalent and in...
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1 CCTV SYSTEMS Analog CCTV systems. 2 CCTV SYSTEMS Analog CCTV systems are still prevalent and in use today, “if it isn't broke don’t fix it” is the prevailing
2 CCTV SYSTEMS Analog CCTV systems are still prevalent and in
use today, if it isn't broke dont fix it is the prevailing attitude
with older systems. We will look at the many different components
that make up these legacy CCTV systems. As a technician working in
the CCTV field it is inevitable that you will come across these
types of systems. Analog CCTV systems are still prevalent and in
use today, if it isn't broke dont fix it is the prevailing attitude
with older systems. We will look at the many different components
that make up these legacy CCTV systems. As a technician working in
the CCTV field it is inevitable that you will come across these
types of systems.
Slide 3
3 CCTV SYSTEMS Here is a mid 60s CCTV console, notice the
rotary phones.
Slide 4
4 CCTV SYSTEMS CCTV recording started with the reel to reel
system which eventually became smaller and then in the late 70s
VCRs (video cassette recorder) were introduced.
Slide 5
5 CCTV SYSTEMS Here is a basic analog CCTV system with a 4
channel multiplexer, a time lapse VCR and a monochrome CRT (cathode
ray tube) monitor.
Slide 6
6 CCTV SYSTEMS HERE IS AN OLDER CCTV SYSTEM WITH THE SIGNAL
FLOW SHOWN: CAMERAS, MULTIPLEXER, DATE/TIME GENERATOR, VCR,
SEQUENCER AND MONITOR.
Slide 7
7 CCTV SYSTEMS Current analog CCTV systems have few advantages
beyond familiarity and cost. Analog CCTV relies on time-lapse
technology. Storage is limited to low-tech tapes, which make
maintenance high and search capabilities low. Analog has low
integration potential and provides no opportunity for remote
access. Current analog CCTV systems have few advantages beyond
familiarity and cost. Analog CCTV relies on time-lapse technology.
Storage is limited to low-tech tapes, which make maintenance high
and search capabilities low. Analog has low integration potential
and provides no opportunity for remote access.
Slide 8
8 CCTV SYSTEMS One of the more commonly known and recognized
components of traditional CCTV systems are the cameras. The first
type of camera that was commercially used was a vacuum tube camera,
similar to CRT monitors and TVs. One of the more commonly known and
recognized components of traditional CCTV systems are the cameras.
The first type of camera that was commercially used was a vacuum
tube camera, similar to CRT monitors and TVs.
Slide 9
9 CCTV SYSTEMS The vacuum tube camera has generally been
replaced by smaller solid state devices, but can still be found in
some surveillance applications.
Slide 10
10 CCTV SYSTEMS Before the mid to late 1980s, a video camera
tube or pickup tube was used for converting an optical image into
an electrical signal. Several types were in use from the 1930s to
the 1980s. The most commercially successful of these tubes were
various types of cathode ray tubes or "CRTs". Before the mid to
late 1980s, a video camera tube or pickup tube was used for
converting an optical image into an electrical signal. Several
types were in use from the 1930s to the 1980s. The most
commercially successful of these tubes were various types of
cathode ray tubes or "CRTs".
Slide 11
11 CCTV SYSTEMS Another key component in CCTV systems,
especially older ones is the switcher. A switcher allows the user
to select which video source to observe. Another key component in
CCTV systems, especially older ones is the switcher. A switcher
allows the user to select which video source to observe.
Slide 12
12 CCTV SYSTEMS switchers are manual or sequencing. A manual
switcher allows the user to select a specific video source by
pressing a button on the switch faceplate. switchers are manual or
sequencing. A manual switcher allows the user to select a specific
video source by pressing a button on the switch faceplate.
Slide 13
13 CCTV SYSTEMS A sequencing switcher changes from one video
source to the next at timed intervals. the time between switching
intervals is usually every 5 to 10 seconds. A sequencing switcher
changes from one video source to the next at timed intervals. the
time between switching intervals is usually every 5 to 10
seconds.
Slide 14
14 CCTV SYSTEMS The camera splitter is a device the allows the
transmission of a single signal based on the synchronization of
multiple signals.
Slide 15
15 CCTV SYSTEMS The splitter allows the user to view multiple
camera views on a single screen. The multiplexer is a replacement
for the splitter, it combines the output of multiple cameras into a
single composite video signal. The splitter allows the user to view
multiple camera views on a single screen. The multiplexer is a
replacement for the splitter, it combines the output of multiple
cameras into a single composite video signal.
Slide 16
16 CCTV SYSTEMS multiplexers are available in increments of
four, such as 4, 8, 12 or 16. the four channel or sixteen channel
are the most common. Having more than 16 images on one screen
renders the images unviewable. multiplexers are available in
increments of four, such as 4, 8, 12 or 16. the four channel or
sixteen channel are the most common. Having more than 16 images on
one screen renders the images unviewable.
Slide 17
17 CCTV SYSTEMS A date and time generator is a special type of
device that superimposes the date and time onto a video signal.
Date and time generators are through-looped, meaning they do not
alter the signal except to overlay date and time data. A date and
time generator is a special type of device that superimposes the
date and time onto a video signal. Date and time generators are
through-looped, meaning they do not alter the signal except to
overlay date and time data.
Slide 18
18 CCTV SYSTEMS The signal is passed on to be displayed on the
CCTV monitor.
Slide 19
19 CCTV SYSTEMS The date and time generator is less likely to
be used in newer installations because date and time functions are
often provided by newer DVR systems.
Slide 20
20 CCTV SYSTEMS In traditional CCTV systems, video is directed
to a VCR (video cassette recorder), it is common to find banks of
VCRs managed by a VCR controller in large CCTV
infrastructures.
Slide 21
21 CCTV SYSTEMS When using a cassette tape to record, you will
generally use a T160 cassette tape for extended recording periods
longer than 48 hours or a T120 cassette for shorter recording
periods.
Slide 22
22 CCTV SYSTEMS Analog systems that utilize VCRs require an
operator to change VCR tapes on a daily basis. These tapes have to
be archived for a certain length of time. Analog systems that
utilize VCRs require an operator to change VCR tapes on a daily
basis. These tapes have to be archived for a certain length of
time.
Slide 23
23 CCTV SYSTEMS VCRs used in CCTV systems utilize time lapse
recording to extend the amount of video data that can be stored on
a single VHS tape. Time lapse recording means that each camera has
a specific amount of time that is recorded. The inputs are split
across a timing interval and stored on a single recording. VCRs
used in CCTV systems utilize time lapse recording to extend the
amount of video data that can be stored on a single VHS tape. Time
lapse recording means that each camera has a specific amount of
time that is recorded. The inputs are split across a timing
interval and stored on a single recording.
Slide 24
24 CCTV SYSTEMS Using the extended recording option eliminates
the need to change out cassette tapes often and is useful for an
unattended recording session over a weekend or holiday period.
Slide 25
25 CCTV SYSTEMS Time lapse recording improves the amount of
video data available for offline review.
Slide 26
26 CCTV SYSTEMS Film is often projected at 30 frames, meaning
30 images appear on the screen every second. Since the playback
speed and the recording speed are the same, the images onscreen
appear to move at normal speed. Film is often projected at 30
frames, meaning 30 images appear on the screen every second. Since
the playback speed and the recording speed are the same, the images
onscreen appear to move at normal speed.
Slide 27
27 CCTV SYSTEMS Even if the camera is set to record at a slower
speed, it will still be projected at 30 frames, thus the image on
screen will appear to move faster.
Slide 28
28 CCTV SYSTEMS A video cassette recorder (VCR) controller
allows the selective control of multiple video recorders. A typical
VCR controller provides several operations to control the actions
of a VCR. Traditional VCRs provide 7 types of control that are
supported by a VCR controller. A video cassette recorder (VCR)
controller allows the selective control of multiple video
recorders. A typical VCR controller provides several operations to
control the actions of a VCR. Traditional VCRs provide 7 types of
control that are supported by a VCR controller.
Slide 29
29 CCTV SYSTEMS The 7 types of controls supported by a VCR
controller: PLAY STOP FAST FORWARD REVERSE PAUSE RECORD EJECT The 7
types of controls supported by a VCR controller: PLAY STOP FAST
FORWARD REVERSE PAUSE RECORD EJECT
Slide 30
30 CCTV SYSTEMS A VCR controller will often support up to 64
VCRs, multiple VCR controllers can be connected together in a daisy
chain. This allows control of several hundred recorders. Alarm
function support is also a typical feature of VCR controllers. A
VCR controller will often support up to 64 VCRs, multiple VCR
controllers can be connected together in a daisy chain. This allows
control of several hundred recorders. Alarm function support is
also a typical feature of VCR controllers.
Slide 31
31 CCTV SYSTEMS A sequencer simply sequences through multiple
images and presents them on a monitor at a specified time set by
the operator (similar to a switcher). An operator can sequence
through a single image at a time or choose to sequence through four
or more images at a time. A sequencer simply sequences through
multiple images and presents them on a monitor at a specified time
set by the operator (similar to a switcher). An operator can
sequence through a single image at a time or choose to sequence
through four or more images at a time.
Slide 32
32 CCTV SYSTEMS The final component of a CCTV system is the
monitor, in older systems the monitor has been a black and white
CRT monitor.
Slide 33
33 CCTV SYSTEMS The typical black and white (mono chrome)
monitor in legacy systems is a 19 CRT (cathode ray tube). 9
monitors are also used but the smaller size is better suited for
view of only 1 camera image though with the use of a quad switcher
4 images can be displayed on a 9. Theyre called monitors because
they do not contain any tuners like a normal TV. The typical black
and white (mono chrome) monitor in legacy systems is a 19 CRT
(cathode ray tube). 9 monitors are also used but the smaller size
is better suited for view of only 1 camera image though with the
use of a quad switcher 4 images can be displayed on a 9. Theyre
called monitors because they do not contain any tuners like a
normal TV.
Slide 34
34 CCTV SYSTEMS Will a regular TV work on a CCTV system? Will a
home VCR work with a CCTV system? Will a regular TV work on a CCTV
system? Will a home VCR work with a CCTV system? Both devices would
work however you would need an F to BNC adapter and of course just
like the old video games you would have to set your TV and VCR to
channel 3 or 4.
Slide 35
35 CCTV SYSTEMS Though color TV was prevalent in late 70s and
through the 80s, CCTV systems still used black and white monitors.
Black and white monitors have traditionally provided much better
resolution than color CRT monitors. Though color TV was prevalent
in late 70s and through the 80s, CCTV systems still used black and
white monitors. Black and white monitors have traditionally
provided much better resolution than color CRT monitors.
Slide 36
36 CCTV SYSTEMS A lot has change with the advent of technology
and now the amount of equipment required in legacy CCTV systems has
been incorporated into one unit, the DVR (digital video recorder).
In the next lecture we will look at the components that comprise a
newer CCTV system, youll notice the list of components will be much
shorter. A lot has change with the advent of technology and now the
amount of equipment required in legacy CCTV systems has been
incorporated into one unit, the DVR (digital video recorder). In
the next lecture we will look at the components that comprise a
newer CCTV system, youll notice the list of components will be much
shorter.