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AVE MULTIVIEW 4C, DUPLEX MULTIPLEXER
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WHAT OUR EXPERTS SAY...
The American Video Equipment Multiview 4C
colour multiplexer/quad provides another clear example of the progress that has
been made in digital video processing microchip technology. It is very compact,
the tough steel case measures just 310 x 280 x 60mm, making it one of the
smallest quad display units on the market. Yet remarkably, the case is actually
twice as deep as it needs to be as the two printed circuit boards inside the
housing occupy less than half of the available space!
Part of the reason for that is the fact that
the mains power supply is housed in a separate unit, even so it is still evident
AVE had no trouble packing in a useful range of facilities, with room to spare.
There are vacant slots for components and sockets on the main PCB which indicates
that the system has the capacity to accommodate additional facilities and up to
8 video input channels. AVE four-channel multiplexers are available in colour
and monochrome configurations.
Both versions have twin monitor outputs, one
dedicated to a quad image, the other can be switched between quad or a full
screen of any of the four inputs. Camera inputs can be selected manually, or
sequenced with a variable dwell time. The multiplexers operate in a duplex mode,
with the facility to display a quad image with a simultaneous full-screen multiplexed
VCR output. Four alarm inputs are provided with normally open contacts; when an
alarm input is triggered the relevant camera input is displayed for a pre-set
period and the VCR switches to real-time recording mode. If more than one alarm
is activated the unit sequences between the relevant camera inputs.
In addition to being very small it is also
very easy to install and operate. Normally installation should take no more
than a few minutes, though it is possible that the power supply could pose a
few problems. The cable linking the mains module to the multiplexer is captive
at both ends, so it cannot be easily disconnected. That may well be necessary if,
for example, the mains or supply leads have to be fed through a small opening.
The only way to separate the multiplexer from its power supply is to disassemble
the case and unplug the supply cable from the PC board.
The rear panel connections comprise a bank of
four BNC sockets for the camera inputs. Above that there’s a 25-pin D-sub
socket for the alarm inputs and VCR control contacts. In the middle of the
panel there are four more BNC sockets, two for the switched and quad monitor
outputs, the other two carry the VCR input and output (play and record) video connections.
Incidentally, for some reason the instruction book shows the panel layout
upside down, though all of the connections are clearly labelled and it shouldn’t
cause any problems.
On the underside there are access holes for
two DIP switches. S1 is used to configure the unit to a time-lapse VCR and set
alarm modes; S2 provides switched 75 ohm terminations for the camera inputs.
There are just nine buttons on the front
panel, eight of them with an associated LED indicator. They are arranged in
four groups. From right to left the first four are concerned with camera selection.
In the middle there’s the quad/full screen selector control, next to that are the
‘live’ and ‘VCR play’ buttons. The function of the live button isn’t very
clearly explained by the manual, however, it engages direct view mode, to show
what is being recorded on the tape. The VCR play button is used to review a
multiplexed tape, either as a quad image, or a full screen display, using the four
camera select buttons. The remaining two buttons are labelled ‘set-up’ and ‘auto’,
the latter engages auto-sequencing.
The initial set-up is very straightforward. Holding
down the auto and set buttons allows camera inputs to be switched in and out of
the sequence, by pressing the relevant selector keys; all programming actions
are confirmed by a double bleep. Dwell time (1 to 255 seconds) is set by
pressing the set button and holding down the auto key for the required amount
of time. The unit automatically detects the number of cameras in use and sets
the multiplexed VCR output accordingly, however, if an odd number of cameras
are used (i.e. 1 or 3), then one blank image will be included in the sequence
as the output will be either two or four channels.
Alarm hold time (1 to 255 seconds) is set in
a similar manner to dwell time, though this time the duration is set by holding
down the set key, and the camera 1 selector button for the time required; a
bleeper sounds at one second intervals. Dwell time for multiple alarm activation is set using the same
procedure, this time using the camera 2 button. The hold time for VCR real-time
recording activation ( 0 secs to 40 minutes) is set using camera 3 button, this
time each one second bleep represents ten seconds of hold time.
The instruction manual is reasonably
comprehensive -- all the information an installer is likely to need is there --
though it tends to make heavy-weather
of some procedures, and some functions could have been explained a little more
clearly. A simple diagram of the front-panel controls, with an a outline of
what they do, would have been a step in the right direction, and some of the
inconsistencies relating to the sockets and control operation would benefit
from some clarification.
OPERATION
Once the installation routines have been
completed all settings are stored in a non volatile memory. There are no
on-screen displays or indicators, other than those generated by the cameras or
a connected VCR. The unit defaults to auto sequencing mode at switch on, or if
the power supply has been interrupted. Manual operation can be engaged at any
time by pressing a camera selector or quad display button.
The alarm mode can be latched or unlatched,
in the latter case the unit will revert to automatic operation after the alarm
event has ended; in the latched mode it has to be manually cancelled by
pressing the set button. The alarm functions can be temporarily disabled by pressing
the set and camera 4 buttons.
PERFORMANCE
Full screen display resolution is in excess
of 350 lines, which comfortably exceeds the capabilities of most time-lapse
VCRs, so it has no impact on recording or playback performance. Picture noise
levels are negligible and colour fidelity is very good, with no noticeable
change to the input signal. Auto switching of free-running inputs results in a
momentary picture disturbance, that lasts for no longer than one frame period,
which in normal use is not significant.
OVERALL ASSESSMENT
The simplicity of the Multiview 4C is one of
its major strengths, and to a lesser extent, one of its weaknesses. Quad and
multiplex facilities are top-rate, it is easy to set up and use and there are no
operational problems. The most obvious difference between this and
similarly-specified quads/multiplexers is the lack of any on-screen displays.
This could be an inconvenience when used with basic cameras, for example, that do not generate an ident. The fairly
basic alarm facilities means that events are not logged or tagged in any way,
which can make it difficult to find a particular sequence on a long duration time-lapse
recording. A plug in power cable might simplify installation in some
circumstances. However all that has to be offset against the unit’s low cost,
performance and the ease with which it can be used to create or upgrade a multi-camera
system, thereby increasing it’s effectiveness.
PRODUCT ASSESSMENT
Design and design features ****
Circuitry and components ****
Ease of installation and wiring *****
Range and variety of functions ****
Accompanying instructions ***
Technical advice and backup ****
Value for money ****
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Ó R.Maybury 1997 2507
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