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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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