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AURORA V816DC-NP 16-Channel Colour Muliplexer
WHAT OUR EXPERTS SAY...
It’s difficult to know where to start with the
Aurora V816DC-NP. It’s best described as a 16-channel digital multiplexer, but
that gives only the merest hint of what it can actually do. The V816DC-NP is
most advanced model in the Aurora range, this particular version works with colour
cameras and has full duplex operation, so it’s possible to review a tape, whilst
the multiplexer continues to function. Eight channel variants are also
available, and there’s a choice of colour or monochrome, and simplex or duplex
operation on the 16-channel models.
In addition to the multiplexing function
there’s a choice of multi-screen display formats -- for live viewing or during VCR
playback -- starting with straightforward 2 x 2 (quad), 3 x 3 (9-screen) and 4
x 4 (16-screen) layouts. Various combinations of screen sizes are also
possible, from a single PIP (picture in picture), to mixed full, quad, 9 and 16
screen displays, plus user-defined selections. Sequencing for the multi-screen
displays and the PIP function can be set manually or selected randomly; camera
dwell times can be set from 1 to 60 seconds. Each camera input can be assigned
an ident and title and the display system generates time, date alarm and
special function messages. The clock can be programmed to auto-correct for
Summer and Winter time changes.
An electronic zoom facility allows any part
of a full-screen image to be enlarged, up to magnification of X12. A set of four direction keys work like a
pan/tilt control, to define the target area. Full screen images can be frozen
at any time, and detail closely examined with the zoom facility. Each camera channel
has its own dedicated monitor output, the multiplexer also has two monitor
outputs. The first one is designated ‘analogue’, this shows a simple camera sequence;
the other is the ‘digital’ channel, and
this displays processed images, showing multi-screen and zoom effects plus camera
and on-screen information.
There are numerous alarm functions, ranging from
digital motion detection and hard-wire/contact triggers (one for each camera
channel), to video loss detection. Various alarm responses are possible, they include
front-panel LED indicators, video displays and an audible buzzer. The recording
frequency of cameras associated with an alarm event is automatically increased,
so it will be displayed and recorded more often during the sequence. All of the
multiplexer’s functions can be controlled from the front panel buttons, a separate
QWERTY-style keyboard, or remotely via a PC using the unit’s RS232/422 serial
interfaces.
The multiplexer is housed in a discrete black
metal box measuring 348 x 190 x 124 mm. Front panel controls comprise three
banks of buttons, most of them having two or more functions. On the far left
are the camera input selectors, which double up as display format selectors, (as
shown by the graphic symbols between the two rows). To the right of that are
four direction keys, used to control the electronic pan/tilt function as well
as select and change items on the menu-driven on-screen displays. Next to that
are four more buttons, variously concerned with menu selection and the electronic
zoom.
On the back panel there is a bank of 36 BNC
sockets, for the camera, monitor and VCR inputs and outputs, there’s also a
pair of mini DIN sockets carrying a Y/C video output, for connection to a S-VHS
video recorders. Three multi-pin D-sub connectors (two 9-pin and one 37-pin)
handle serial communications and alarm connections. The standard of construction is generally very good, and the
device comes with a very complete accessory kit, that includes fixing hardware,
blank plugs and 75-ohm terminators, for unused video channel outputs.
All functions are controlled from the
menu-driven on-screen displays, which is fine except that unbeknown to us our
sample had been configured for NTSC colour. This produced an unwatchable
display when connected to a PAL monitor. Unfortunately the instructions make no
mention of this possibility, and there’s only scant reference to changing the
set-up. In any event this is of academic interest as the colour system setting
can only be changed from the on-screen display. We only discovered the cause of
the problem by luck, after connecting the unit to a multi-format monitor, to
check whether the original monitor was faulty.
In spite of Vicon’s claims for
user-friendliness the on-screen display system can be quite difficult to
navigate. It’s easy to make mistakes, that can be difficult or time consuming
to rectify. The main problem concerns the need to confirm every action by
pressing the enter button, before and after any parameter is changed. It’s not
a particularly intuitive method, and it
can become quite tedious. Some form of menu map in the instructions would have
been welcome, and the supposedly helpful directions at the beginning of each
section, shed little light, especially if you manage to get lost (which we did,
frequently!). Here’s a typical example: ‘Keystrokes from the main menu for the
restore setting must be edited to ¯,¯,¯,¯,¯, Enter, ¯,¯, Enter,
¯,¯,¯, Enter’. Work that one out...
Information detailing how to set-up the
numerous sequencing options for the multi-screen and PIP display formats take almost
one third of the 115 page instruction manual (not counting the addendum’s and
additional software data supplements...). To be fair it does get a little
easier with practice, but there are many options, variables and pre-set
adjustments to contend with. Configuring a full 16-camera system and alarms could
take quite a while!
Recording VCR set-up is relatively simple though,
and the system contains a library of operating parameters covering most makes
of VCR currently available, manual adjustment is also possible, for models not
included.
OPERATION
In normal use -- following the initial set-up
-- only the top-level menus need to be accessed with any regularity; most other day-to-day functions, like camera
and display format selection, can be made from the front-panel buttons.
The zoom facility is engaged by pressing the
appropriate camera selector button twice, this can be on a live or frozen
image. It works in a slightly unusual way and homing in on a particular area needs
a fair amount of dexterity. The system cannot zoom and pan/tilt simultaneously;
this involves repeatedly stabbing the zoom button, re-aligning the image, and
zooming again, with the tendency to overshoot increasing as the level of
magnification increases.
Alarms can be acknowledged manually or
automatically, in the manual mode a buzzer sounds, which the operator has to
cancel. The alarm output can printed out using the RS232 serial output.
PERFORMANCE
Video processing takes place in the digital
domain, and there is a slight textural change to the image; colour contrast is
reduced slightly but noise levels and resolution remain largely unaltered during
a video signal’s passage through the multiplexer.
The digital effects, in particular freeze and
zoom, do result in a noticeable reduction in image quality. The increase in pixellation
or blocking is not too bad below x6 magnification (as shown on the display),
but at higher zoom settings fine detail is quickly lost. Multi-display and
sequenced images are very clean, the update frequency is increased on camera
channels where movement has been detected, which helps reduce the jerkiness of
movement during live display or VCR replay.
Variable brightness, saturation and contrast
allow the picture to be optimised for the viewing conditions.
OVERALL ASSESSMENT
In spite of our misgivings about the
friendliness -- or otherwise -- of the on-screen menu system, the multiplexer
works very well indeed. Features like the electronic zoom could be genuinely
useful, though it has to be said, it’s no substitute for the real thing. However,
the combination of basic functions -- multiplexing, multiple-display, alarm functions, and duplex
operation -- and smooth, near faultless on-screen performance, sets this device
apart from the competition.
PRODUCT ASSESSMENT
Design and design features 8
Circuitry and components 9
Ease of installation and wiring 7
Range and variety of functions 9
Accompanying instructions 7
Technical advice and backup ?
Value for money 8
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Ó R.Maybury 1996 0507
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