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PHILIPS VSS8250 PRO-VISION SYSTEM

 

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Philips Pro-Vision is a compact, modular multi-camera surveillance system, designed for small to medium-scale installations. The core component is the VSS8250 14-inch colour monitor/switcher unit, with provision for up to four VCM 9175 line-powered colour cameras. Additional cameras can be connected, using one or two external junction boxes, which increases the system’s capacity to 7 and 10 cameras respectively.

 

The key features are ease of installation, flexible operation and expandability. Cameras connect to the monitor/switcher using pre-formed cables (4-wire twisted pair) with US-style RJ 11E telephone plugs at either end. Cable runs of up 150 metres are possible, these can be extended by up to 200 metres at a time, using an optional adapter box. The cable carries the video signal, camera power, plus two-way audio (with an optional intercom box) and switching signals for external devices.

 

MONITOR SWITCHER

The monitor/switcher unit is housed in a sturdy white-fronted, metal-framed cabinet with a retractable tilt-stand on the base. All of the switcher’s functions are controlled from a multi-lingual (English, French or Dutch), menu-driven on-screen display. The main menu covers pre-setting the camera switching order, sequence time (fixed intervals of 2, 4, 7, 10, 20 and 60 seconds), alarm configuration, time/date overlay, language selection and VCR record/replay options. These include a multiplex mode, whereby the camera switching rate is increased to 25 frames per second (the monitor display is disabled). Multiplex recordings can be replayed a frame at a time on VCRs (with stable still-frame replay), or via a de-multiplexer.

 

Front panel controls comprise a master on/standby switch, buttons for menu call and select, camera up/down selection, sequence start/pause, ‘talk’ and ‘action (more about those in a moment. The menu buttons can be disabled, to prevent tampering or restrict operation; a 4-digit user-defined PIN code is required to unlock the controls. Behind a hinged flap that runs the width of the front panel there are adjustments for volume, colour saturation, brightness, contrast and a recessed pre-set for horizontal shift. In the monitor standby mode the display is disabled but the switcher and cameras remain active, so the output may be recorded, or viewed on external monitors.

 

In addition to the four dedicated camera inputs on the back panel it has a set of video and audio input/outputs (phono/RCA sockets) for a VCR loop-through, plus secondary video and audio outputs, for a slave monitor. There’s also a screw-terminal block for the alarm output connections.

 

Incidentally the PIN-coded control lock is only moderately secure, as we discovered when the mains plug worked loose, momentarily disrupting the supply, erasing the stored code. The PIN can also be reset -- if it’s lost or forgotten -- using a simple procedure outlined in the instruction manual.

 

ALARM OPTIONS

Various alarm configurations are possible. In the absence of any additional sensors an alarm bleeper will sound, an on-screen display appears and the switched alarm output on the back of the monitor is enabled when there’s a break or short circuit on any of the camera inputs. Optional alarm boxes with N/O or N/C contacts can be connected to any camera. When triggered by a sensor (door/window contact, PIR etc.) the switcher stops sequencing, displays the relevant camera output, along with an on-screen display and the alarm bleeper sounds. The switcher can be programmed to reset and return to normal operation after a pre-set delay of 30 seconds or 3 minutes, or it can be set to remain in the alarm condition until manually reset. The time and date of the last alarm event (but not the camera ident) is logged and displayed on the camera select menu.  

 

The cameras are fitted with built-in microphones, with the audio heard through the monitor speaker. The optional intercom box connects between the camera and the end of the monitor cable; a microphone is mounted behind the front panel, next to the ‘talk’ button; pressing it allows the user to be heard over the intercom speaker. The monitor’s ‘action’ button is used to activate a relay inside an optional action-box, that also connects between the camera and monitor cable. This can be used to operate external devices, such as a remote door lock. Although the system has been designed to use the VCM9175 and compatible colour or monochrome cameras, other makes and types can be connected with a camera interface box. This has sockets for composite video and RF inputs.

 

CAMERAS

The VCM9175 colour camera is housed in a small (60 x 7`2 x 92 mm) shielded plastic case. The image sensor is a 1/3-inch CCD with 300k active pixels. The operating range is quoted as 3.5 to 30,000 lux, with a resolution of 330-lines. The front of the camera is fitted with a CS mount and it comes with a 4 mm F1.2 lens as standard. Other types of lens can be fitted; there’s an auto-iris socket on the back, next to the ‘telephone’ socket carrying the power and video feeds. The only user adjustment is a miniature slide switch for turning the built-in microphone on or off.

 

Mounting hardware is supplied in the shape of a universal wall bracket with a ball and socket head, that screws into a threaded collar (1/4-inch UNC) on the underside of the camera. This is different to the illustration in the instruction manuals, which shows the mounting collar on the camera’s back panel, a small bolt-on right-angle plate is included so that it’s possible to use an overhead or ceiling type mount with the supplied bracket.

 

Both the monitor/switcher package and cameras come with reasonably comprehensive installation instructions, including useful advice on camera positioning and lens selection, for specialist applications. An optional weatherproof housing is available for outdoor installations or harsh environments.

 

INSTALLATION

It’s difficult to imagine how Philips could have made it any simpler with only one connecting cable per camera to worry about. Even the mounting bracket comes complete with screws and wall-fixing plugs, in fact the only tool needed to install the system is a screwdriver... Programming the sequencer and alarm functions is fairly painless, the only other set-up adjustments concern the use of cable extension, alarm and junction boxes (if fitted), aligning the cameras and focusing the lens.

 

PERFORMANCE

The supplied cameras performed well with resolution spot on the stated 330-lines. The auto exposure system is responsive and capable of dealing with sudden changes in lighting level. In the sequence mode the image sometimes pulsates for a few moments if the scene contains a single bright light or reflected sunlight. On a short duration sequence (2-4 seconds) the camera may not compensate in time before the image switches. so care needs to be taken during camera alignment to prevent this happening. Low light performance is good, yielding a useable, though somewhat grainy image, down to typical room lighting conditions.

 

Colour accuracy is also very good in strong natural and mixed lighting conditions. Reds and greens appear slightly exaggerated in tungsten light whilst tube lighting results in a slight greenish-yellow caste.

 

The switching action is very smooth, it occurs within a single frame with no visible picture disturbance at the changeover points. In the event of a power interruption the system switches back on to the previously selected mode, the clock has a long-term battery backup and will not require re-setting.

 

OVERALL ASSESSMENT

There’s a few minor niggles. The most annoying one occurs when the system is in multiplex recording mode, where the time/date overlay is suppressed. This means that unless the VCR has a time/date stamp there’s no easy way of logging non-alarmed events, especially on long-duration recordings. It’s a good idea to switch the monitor off when the system is in this mode as the display becomes slightly unstable. The alteration to the mounting collar layout on the cameras is a nuisance, and the alarm event log is fairly rudimentary.  

 

Apart from that the system works very well indeed, and it’s worth repeating that it’s virtually idiot-proof, exceptionally simple to install and use, once it has been set up. Image quality is good and the cameras can cope with a wide range of undemanding lighting conditions without difficulty. Philips have struck a realistic compromise between performance and features. The system should easily meet the needs of most end-users, looking for a simple and cost-effective multi-camera system, that easy to install, operate and maintain.

 

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 1995 0609

 

 

 

 

 


 

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