|
ROBOT MULTIVISION OPTIMA II
MV216 Multiplexer
INTRO
WHAT OUR EXPERTS SAY
COPY
Vision multiplexers have become a key element
in multi-camera surveillance systems by making the most efficient use of
time-lapse VCRs. Unlike most of the other components in CCTV systems, video
recording devices have not experienced anything like the same cost reductions,
and so by default have become an expensive resource that requires careful
management.
Robot Research have been at the forefront of
multiplexer technology and their latest Optima II range embodies many of the
most recent developments in digital video signal processing. The MV216 we’re
looking at here has 16 camera inputs, (a 9-camera version with a similar spec
is also available) and it’s worth reiterating that the cameras can be any
suitable PAL/CCIR spec devices, synchronisation is carried out inside the
multiplexer and there no need for external genlocking.
The MV216 has five main monitor display modes
of 1, 2, 4, 8 and 16 live colour pictures, and a multiplexed VCR output. Additionally
there is a moveable 2x zoom mode and picture-in-picture facility. The MV216
features full duplex operation, with multiplex recording continuing in the
background whilst the unit is being used to display multiplexed recordings from
a second VCR. There are two monitor outputs, one showing a live or recorded
multi-camera display, the call monitor output shows a single selected camera
input.
The headline features, though, are dynamic
time division multiplexing (DTD), and video motion detection (VMD) that work in
conjunction with one another to vary camera recording times according to the amount
of movement in each picture. In other words, images with no significant
movement are recorded less frequently, resulting in a more efficient use of the
recording VCR and less wasted tape. The VMD system employs a matrix of 192
switchable ‘targets’ covering the image, these can be switched on or off to
define areas of interest, it then compares successive fields from each camera;
if a change is detected -- i.e. there is activity in the target area -- the sample
rates for that camera, (or cameras) are increased. The VMD facility can also be used as an alarm function, alerting
the operator to movement, displaying the relevant camera and closing an alarm
contact.
Other important features include a menu-driven
on-screen graphics with time, date, alarm status, video loss displays plus 10-character
camera idents. It has single ‘priority’ camera recording, composite and S-Video
VCR input/outputs, and an internally-generated colour bar test card for monitor
adjustment. The MV216 has a non-volatile memory, which protects programmed data
during a power loss, and an RS232 interface, that can be used for an optional
remote front panel, (mounted up to 1000 feet from the unit), alternatively key
functions can be controlled by a PC using suitable communications protocols.
LAYOUT AND OPERATION
The slim steel case that houses the MV216
measures 432 x 311 x 44mm. The front panel is occupied by a row of buttons, 16
for camera selection and VMD set-up, plus four other groups of display mode, menu
select and function keys. The back panel is equally straightforward, with 36
BNC sockets assigned to camera, monitor and VCR inputs and outputs. There are also
two S-Video sockets, for S-VHS or Hi8 VCRs, plus two 25-Pin D sockets carrying
remote control and alarm interconnections. DC power is supplied by an external AC
mains adaptor.
All of the set-up routines are accessed from
the on-screen display’s menu selection. Pages one and two are concerned with
time and date adjustment and night/day operation, page three covers alarm settings,
and page 4 deals with VCR parameters. The next three pages concern VCR timings,
camera dwell, title composition and motion detector set-up. The last page
contains the security lock options, alarm event and status displays.
At switch-on the MV216 defaults to a 4 x 4 (16)
camera display and multiplexed VCR output. The five display select buttons
switch between the single and multiple (2, 4, 9 or 16) picture modes; the single
image key also toggles the 2x zoom display. The magnified area is shown on an
inset sub-screen and defined by a moving cursor, superimposed onto the main
picture. The PIP display mode button flips between two selected camera inputs.
The MV16 has four alarm operating systems: it
can be triggered by up to 16 mechanical alarms, associated with each camera input;
it has a motion alarm that is activated by movement in the camera image; the recorded
alarms respond to VIS codes recorded on tape and sensed during playback, and a video
loss alarm that is engaged if any camera input is lost. The response varies
according to the type of alarm input, but it can involve flashing the relevant
camera indicator light, energising the unit’s alarm relay, sounding a buzzer, displaying
a relevant alarm message on the monitor screen, and where necessary switching
to the alarm encoding rate or camera priority mode on the VCR output.
Routine operations are unambiguous and simple
to understand, though the instructions are fairly dense in places, and some
operations could be more clearly explained with the use of diagrams,
nevertheless all the necessary information is included.
PERFORMANCE
The quality of image output from the MV216 is
most impressive, despite the indications of the extensive digital processing
involved. This results in a small reduction in detail and dynamic range,
compared with a raw analogue camera output. Noise levels are low and colour
fidelity is very good. In the multiple image display modes there is a further reduction
in resolution, though this does not affect the multiplexed VCR output. Playback
picture quality is entirely dependant on the performance of the recording VCR. S-VHS equipment will resolve slightly more
detail, and noise levels are generally lower.
OVERALL ASSESSMENT
The quality of construction, design and
performance are all remarkably good, moreover installation and operation are
difficult to fault. The DTD and VMD facilities give this device a significant functional
advantage over similarly-specified multiplexers, and must qualify as critical
features that should be taken into consideration when specifying a multi-camera
system. Robot are the acknowledged leaders in the field of video multiplexing
and it clearly shows on the MV216 which exhibits a high level of refinement and
sophistication.
BOX COPY 1
PRODUCT ASSESSMENT
Design and design features *****
Circuitry and components *****
Ease of installation *****
Range of functions ****
Accompanying instructions ***
Technical backup ****
Value for money
---end---
Ó R. Maybury 1995 2610
| 
