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Video multiplexers have become an indispensable tool in small and large-scale multi-camera systems. The Montage range of multiplexers from Vision Factory offers specifiers, installers and end-users some unique facilities.



Video multiplexer technology has advanced in leaps and bounds during the past few years, bringing with it significant improvements in performance and versatility as well as some very welcome economic benefits. However, a lot of products on the market appear to have quite similar sets of specifications. The Montage range of multiplexers, from The Vision Factory, is different though, broadening the choice for installers and end users, particularly on larger systems, using up to 32 cameras.


Many of the options on the CD24 (24 camera colour duplex version) multiplexer we’re looking at here, will be familiar. They include a range of standard display formats; there’s 2x2, 3x3 and 4x4 screen layouts, but in addition there’s a 5x5 display, plus a range of composite patterns, that ultilise a mixture of screen sizes. The facility to customise displays -- Vision Factory call them ‘presentations’ -- by positioning different-sized sub-screens anywhere on the display is also highly unusual. This enables operators to make the most efficient use of a monitor display, to suit the conditions and surveillance priorities, and ease the operators workload.


Flexibility is a key feature. Each camera input has an associated monitor output, additionally there are a range of monitor and VCR outputs with provision for component (Y/C) and RGB outputs, for the main monitor. This will ensure maximum picture performance from colour cameras, moreover the RGB output will give the best results when the system is used in conjunction with a colour video printer.


Live camera or off-tape images can be frozen and zoomed for display and analysis purposes, or to produce hard copies. Duplex operation enables off tape images to be reviewed while normal multiplex recording continues. Multiplexers in the Montage range have a full set of alarms, associated with each camera input and the system reacts to video loss or camera failure. Alarm status is displayed and recorded, and activation’s are displayed during replay. Camera channels have their own user-definable idents, along with a time and date display.


All operations, configuration, picture settings and set-up routines are controlled from a simple to use menu-driven on-screen display system. Settings are permanently stored on an EPROM and protected against power failure. Access to the system and accidental or deliberate interference can be prevented using a control lock that’s activated by a 4-digit PIN code.



The CD24 is housed in a sturdy rack-mountable steel case measuring 440 x 440 x 90mm. The front panel keyboard is detachable for remote operation (up to 100 metres distant), a front panel blanking plate is supplied when this option has been specified.


Input and output socketry is grouped together according to function on the back panel. Camera inputs and outputs are arranged in pairs, each set of 8 input and output sockets is associated with a bank of miniature DIP switches, that select the appropriate termination for used and unused outputs. On the right side of the back panel are the monitor, VCR, external control and alarm connections. Composite video feeds are handled by standard BNC sockets; Y/C and RGB signals are clustered together on a pair of 15-pin D-sockets.


The front panel controls are in four groups. Main functions (live, replay, record and tape monitor) buttons are on the left side. A row of 12 ‘function’ keys running along the lower edge of the panel selects the various ‘presentation’ screen displays. To the left there’s a bank of 12 keys for selecting individual camera inputs, zoom and freeze functions, and sequence display for a spot monitor. The numeric keypad on the far right is used to nominate camera inputs, PIN number entry, and there’s a set of cursor buttons, to control the on-screen display.



The on-screen display is used primarily to configure the system and select various sequencing, alarm and ident options; once set most routine operations can be controlled from the keypad without reference to the on-screen displays. Montage is designed to be used in conjunction with time-lapse VCR and again there are numerous options, based around different types of machine. The system does not require programming to operate with a particular make or model of VCR, giving it the maximum flexibility to work in a variety of configurations. This includes installations where machines are cascaded, to make the most efficient use of tape, and minimise the effects of longer delay times, associated with more complex multi-camera systems.



Vision Factory have used some of the latest generation of digital video processing microchips, that ensure clean resolution and good colour fidelity, even on the smallest sub-screens. The multiplexer is relatively transparent to the signals passing through its processing circuitry. Inevitably some artefacts are visible, and some detail is lost, though it is relatively insignificant, and comparable with most other multiplexers on the market. Luminance and chrominance noise levels in all display modes are very low, images appear clear and well defined, though a lot will depend on the capabilities and characteristics of the cameras, monitors and video recording equipment it is used with.



Montage is a competent, well-designed  system that’s easy to install, configure and use. The range of options caters for the widest possible range of applications and the system’s flexibility, particularly when it comes to the variety of display functions is most impressive. A definite step forward in the field of large-system multiplexers.




Video system                       PAL colour, CCIR black and white

Screen formats                5 x 5, 4 x 4,  3 x 3, 2 x 2, multi combination, PIP, overlap, user-definable              

Video level:                           1.0 volt p-p, 75 ohms (composite)

Video in/out                           composite, component Y/C or RGB

Alarm                     one input per camera (N/O or NC contact)

Alarm output                         output relay 1.5A N/O and N/C contacts


Connections                         camera in/out, monitor & VCR BNC, S-Video, RGB alarm and RS232/RS442 external control (D connectors)

Power requirements                110/2410 VAC 50/60Hz, 50 watts

Dimensions                         440 x 440 x 90mm







Product design                    8

Build quality                                          8

Electronics quality                    9



Ease of installation                            8

Set-up functions                  9

Instructions                                           8

Manufacturer’s support  8



Functions                                              8

Ease of use                                          8



Image quality                                        8



Ó R. Maybury 1996 1907



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