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Whilst there is absolutely no question that recorded video is the most important security tool yet devised its worth, as evidence, is entirely dependent on the amount and type of information captured in the picture. There are many situations where a moving image – no matter how crisp and detailed it might be -- is simply not enough. For a video recording to have any real value it needs to be backed with incontestable data, the most obvious example being a permanent time/date stamp, burned into the recording, which removes any doubt as to when an event took place.


Until comparatively recently the amount of extra information that could be easily added to a video image was confined to mundane things like camera titles and alarm indications, however within the past few years the number of devices that generate potentially useful data has multiplied. Unfortunately in a lot of instances the difficulty or expense involved in making use of this information has meant that an important facility often goes unused. 


American Video Equipment’s VSI Pro provides the vital link between devices that generate data -- such as cash registers, ATMs, barcode scanners, access control panels, PCs, printers -- and video surveillance and recording equipment. VSI Pro is currently AVE’s most advanced ‘video serial interface’, adding a number of extra features to its already successful VSI+ model. The VSI Pro is housed in an unassuming little box measuring just 125 x 125 x 40mm with four buttons on the front. The feature list is extensive so we’ll begin with the basics. The core feature is the VSI Pro’s ability to superimpose alphanumeric characters from virtually any device with a RS-232 serial communications data link into just about any video source (NTSC, PAL, SECAM, CCIR, RS-170, RS-230). To that end on the back panel there are two BNC sockets, for the video input (from a camera) and output (to VCR, multiplexer, switcher etc.) and a 9-pin D-Sub socket for the data cable. An external 12-volt DC mains adaptor supplies power.


The inserted display can be presented in a variety of formats and character sizes and positioned in any part of image. The user or installer can also change the way the display looks by altering the grey scale and background. VSI Pro has its own built in time/date generator or it can be locked to the time/date output of the cash register (or whatever device it is connected to). Installation is or should be very straightforward since the VSI Pro is programmed to operate with 28 makes of cash register, more are being added all the time.  In any event most of the communications and display settings can be set manually, to accommodate devices not yet included in the VSI Pro’s software library, but more about that in a moment. All user-set information and logs stored by the unit are held in a 32k static RAM memory (SRAM) with battery backup. High-speed data buffers ensure the VSI Pro can work with the latest and fastest registers


Two alarm outputs are provided, which are linked to one of the VSI Pro’s most powerful features. Up to 16 alarms ‘events’ can be set, including triggering by a specified string of characters or control codes generated by the source device or by programmable ‘Exception Reports’. The latter gives the user the option to set the unit to identify doubtful transactions and respond with an on-screen alert, trigger an external alarm device or VCR or send data to another device via a serial communications link. Up to 24 Exceptions can be set, common options include Void, Refund, Return and Coupon, transactions relating to specific departments or products, transactions by a particular cashier and sales above, below or between pre-set cash values. 


Everything is controlled from the four front panel buttons. Whilst in normal operating mode the buttons can be used to move the display field around the screen, otherwise all operational settings are accessed from a menu-driven on-screen display. The menu’s opening page has nine items that lead to a series of sub menus; the main options are: Register Select, Screen Setup, Text Display, Communications, Exception Report, Alarm Outputs, Test/Demo mode, Down/Up Load Setup and Help. To get a better idea of what the VSI-Pro can do and how easy or difficult it is to setup we’ll look briefly at each one in turn.


The Register Select menu is used to specify the make of cash register, each selection contains configuration settings for that particular make or model of till. Screen Setup opens up a sub menu page with six further items: Character Size, Border/Grey Scale, Horizontal Position, Vertical Position, Clock and On-Screen Title. The 9 x 20 character display field has 10 size and 10 grey scale settings, the latter ranging from peak white to black, with a transparent or shaded background. The horizontal and vertical position adjustments are the same as those available in normal operating mode and the clock adjustment sets time and date, the display format and the facility to lock the VSI Pro to time/date information coming from the register or device. The On-Screen Titler function allows the user or installer to compose a one-line ident of up to 20 characters that appears above the transaction data; we’ll come back to an odd quirk of this facility later on.


The Text Display menu provides additional formatting controls, including options to set how long the display remains on-screen (always on – until replaced by a new transaction -- 6, 12, 20, 30, 60, 120, 180 or 300 seconds). The sub menu also contains a setting to change the number of display lines, truncate and compress text lines over 20 characters long, left justify on/off, scroll delay and display on/off. More detailed changes to the communications protocols are made under the Communications menu with adjustments to transmit and receive data rates, set parity, data bits, handshake and auto linefeed switches.


Selecting Exception Report on the main menu brings up a sub menu with four items: Exception History, Set Exception, Output and Time Stamp. Exception History logs the 100 previous Exceptions. Set Exception is used to program exceptions using the previously discussed criteria (type of transaction, operator, value etc.). Output toggles a serial data output on and off, to trigger an external device such as a printer etc, and Time Stamp switches a time/date stamp on the exception output on or off.  Programming an Exception is relatively painless and it involves entering the relevant words or characters (i.e. Refund, No Sale etc.,) exactly as it appears on the video output, into the ‘string’ field.


The facility to program the 16 alarms is on the Alarm Outputs sub menu. The options covered are trigger by single exceptions or groups of exceptions, output switching (NO/NC), alarm duration (pulse, 6, 12, 20, 30, 60, 120, 180 or 300 seconds), on-screen flag type (static or flashing asterisk or black/white text), flag duration (6, 12, 20, 30, 60, 120, 180 or 300 seconds), and an entry field for the setting ‘Triggered Text’ data string, which if enabled, will activate one of the 16 alarms when a particular string of characters is output or displayed by the connected device.


The Test/Demo Mode menu item covers send and receive checks for the data port, simulated transactions from a cash register, display the software version number and a kind of screensaver showing the AVE logo. Down/Upload setup is used to copy or transfer VSI Pro setup information between other VSI-Pros or a PC and finally, the Help menu defines the actions of the front panel buttons.


There’s relatively little to say about the menu system, it has been generally well thought out and although the buttons are quite fiddly and close together, it’s is intuitive and simple to use. The only thing to watch out for is an apparent bug in the operating system whereby – on our sample at least – the unit would returning it to factory defaults, wiping all the user settings and data in the process, if the Reset button was pressed whilst composing a on-screen title (which is quite easy to do as the buttons are so close together). According to the manual a Master Reset should only be possible by pressing a specific sequence of buttons that is almost impossible to do accidentally. 


Installation poses few problems; the instruction manual assumes a certain amount of familiarity with the type of devices the VSI Pro will be used with and it tends to get a bit dense in places, but all of the information most installers are like to want or need is there. Construction quality is very good indeed, the single densely packed PCB is built to very high standard and the metal case is tough enough to survive in the unfriendliest environments. 


Video passes cleanly through the unit with no perceptible increase in noise, change in brightness, colour or stability so from that point of view it gets a very clean bill of health. The legibility of the inserted transaction data is very good and there’s sufficient adjustment to change it to suit the type of image and scene brightness. Using conventional low-cost and mid-range colour and monochrome cameras the stability of the data remained rock solid at all times.


VSI Pro is a thoroughly well designed and highly competent piece of kit, apart from the apparent software glitch that wipes all user settings, it performs flawlessly. It’s an important enabling technology, allowing potentially important data to be efficiently captured, displayed and recorded  increasing the value of conventional video surveillance by an order of magnitude.




Power supply              12VDC (via supplied AC adaptor)

Weight                        0.5kg

Dimensions                 125 x 125 x 40mm





Product design             9

Build quality                           9

Ruggedness                            9



General functions                     9

CCTV functions                     n/a      

Ease of use                             8

Instructions                            8

Manuf. support                        ?         

Performance                           9

Video quality                          10



Ó R. Maybury 2000 2408



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Copyright (c) 2005 Rick Maybury Ltd.