Testing and Commissioning Systems
It is assumed that an installation has been completed according to the specification and the relevant regulations. It is also assumed that pre-assembly of all the system’s components will have been carried out according to the relevant manufacturers’ instructions. The time has arrived to test, commission, and hand over the system to the customer. There are four main aspects to this final phase.
- Testing individual components to ensure that they operate to the design specifications.
- Commissioning all the components to function as an integrated system.
- Demonstrating the system and its operation to the customer.
- Training operators in the use of the system.
Although most components should have been checked and, if necessary, pre-assembled before dispatch to site, the final setting up can only be carried out during installation. Although the degree of setting up will vary according to the size and complexity of the system, there will be certain procedures that will be common to most systems. The following is a very brief checklist of some key aspects that need attention.
Cameras and Lenses
Check that the correct lens is fitted in line with the specification. Set up the lens focus and back focus of the camera. If automatic iris lenses are fitted, adjust the peak/average and level potentiometers. Check that the field of view is as required. This will usually be adjusted using a hand held test monitor. There is also available a hand held focus adjuster. If the camera has to cope with a wide range of light conditions, fit a neutral density filter to set the focus at the maximum lens aperture.
If a zoom lens is fitted, check that the scene remains in focus throughout the zoom range. If the focus changes, it may be necessary to recheck the camera back focus.
Check every video cable for continuity and shorts to earth. A common problem is ‘whiskers’ of the braiding on a coaxial cable touching the core conductor. If twisted pair transmission or video line correctors are fitted then the only correct way to set up the system is using a pulse bar generator.
Check through every video line to ensure that all terminations are set correctly.
Check the dwell time and sequencing of standard video switchers. In the case of matrix switchers set up the dwell times and sequences for each monitor. If there is a master/slave situation, ensure that the units are correctly located with the master control at the main control location. Again, check for correct terminations.
Check that all functions are operating correctly and that end stops are set as required. Make sure that the pan right and tilt down controls correspond to the right direction of movement. If pre-set positions are incorporated, set them up according to the manufacturers’ instructions and to the specified fields of view.
Set the time, date and camera titles. There will almost certainly be options to set up the various multiscreen displays. It is always necessary to program the multiplexer according to the video recorder in use. Most multiplexers now have an on screen list of current VCRs available, in which case selection is straightforward. If the VCR installed is not on this list then it will be necessary to check with the multiplexer manufacturer to establish the correct settings.
Some systems are supplied with separate tapes for each day of the week or month. Ensure that all the tapes and boxes are marked accordingly.
All time lapse video recorders can display the time and date on the screen. If the recorder is the only system component that provides this information then set it to display. If there is a multiplexer or switcher that generates the information then set the recorder not to display and use the other component for this function.
Video Motion Detection
All video motion detection systems require a great deal of time and care in setting up if they are to function efficiently and not generate false alarms. In the case of external systems, it will be essential to carry out the main programming at night under the worst lighting conditions. If the system is installed in the summer then it will always be advisable to return in the winter to finalise the settings.
Free Space Transmission
All types of free space transmission systems need rigid mountings with correct brackets to allow alignment. Always use the manufacturers’ alignment test instruments to obtain the optimum signal strength. It is never possible to assess the signal simply by observation of the picture.
Interfacing With Other Systems
If the CCTV system is being connected to another system it is advisable to have a representative of the company which installed that other system visit the site and approve the connections.
Commissioning the System
Once all the components in an installation have been checked and set up it is then necessary to commission the system to function as set out in the specification documents. This really means operating the system from the controls and ensuring that every function and view is as originally designed. There will usually need to be some fine adjustments made to cameras, lenses, and angles of view, etc. At this stage, a record should be made of every camera and the scene in view. It is also advisable to comment on the detail that can be seen at various distances from the camera.
Commissioning will often necessitate operating the system through the night if appropriate. Particular note should be made of the views and focus of cameras using infrared illumination. There may be areas of flare or dark pockets that must be considered. It is not always easy to predict at the design stage what the effect of infrared illumination will be. Therefore, during the commissioning stage consideration should be given to reducing or increasing the power of some of the lamps if they are not producing the expected results.
Operation and Maintenance Manual
When the system is complete, an operating and maintenance manual must be handed over to the customer. This should contain a copy of the agreed specification and equipment schedule, and will form the basis of the commissioning procedures and tests to be carried out. The manual should contain a copy of all manufacturers’ data and installation specifications. The aim should be to provide the customer with sufficient information to be able to have the system maintained by any competent company in the future. The need to produce this manual should be considered in the price quoted for the system in the first place. Produced effectively, the manual will represent a significant cost that should not be ignored.
An important aspect of commissioning the system will be to record all programming and equipment set up procedures that have been carried out. These will need to be included in the final operation and maintenance manual that will be handed over on completion. There may be such items as the programming of multiplexers, the programming of alarm handling, sequences set up on matrix switching systems, etc. These should be fully documented in the system manual.
This article is an extract from chapter 22 of 'The Principles & Practice of CCTV' which is recognised as the benchmark for CCTV installation in the UK.