Týždenný prehľad DIPOLu - TV a TV, CCTV, WLAN

Drones at the service of the Police.

The Polish National Police is testing the possibility of using drones for the prosecution of road traffic offenses. The use of the drones should improve the safety on roads. The first tests were aimed to control the situation at pedestrian crossings, where there had already been more than 200 accidents this year. After each take-off, the drone designed by the Silesian University of Technology recorded traffic violations: pedestrians crossing streets on a red light, drivers passing a red light, drivers overtaking or passing a vehicle that had stopped at a pedestrian crossing, drivers or pedestrians forcing priority at pedestrian crossings. The camera also recorded other offenses, such as non-use of seat belts or prohibited use of mobile phones while driving.

The drone tested by the police in Katowice, Poland
(source: KWP Katowice)

The tickets for the offenders were given by special patrols. One of them operated close to the pedestrian crossings, the second stopped drivers a few hundred meters away from the inspection areas, within the communication range of the drone.

A policeman operating the drone
(source: KWP Katowice)

The use of drones by the police is not limited to the monitoring of intersections and pedestrian crossings. The biggest advantage of this type of machines is the observation of the areas of interest from above. This perspective provides an opportunity to see phenomena hardly discernible from the traditional, ground point of view. Cameras with with optical zoom can capture many details, as well as are able to cover wide areas. These features make the drones very useful to secure mass events, open public spaces, expressways, railway lines and freight trains.

The use of UTP cable for transmission of video from HD-TVI cameras.

The recommended transmission medium in HD-TVI systems is the coaxial cable. RG-59, the most popular cable used in CCTV, can transmit HD-TVI video over distances up to 300 m, keeping fine detail in the image. Cables with larger diameter of the central conductor ensure longer ranges (e.g.. Triset-113 E1015 - over 500 m), however they cost more and are more difficult to install. The application of a UTP/FTP cable instead of coaxial cables has important advantages. The installation of the twisted pair cables is easier due to their flexibility and versatility - one cable containing four pairs can transmit signals from more than one camera and/or be also used for power supply. The application of the cables for video transmission is connected with the use of impedance matching devices, i.e. matching the 75 Ω unbalanced impedance of analog CCTV systems to the 100 Ω balanced impedance of the twisted pair, located on both sides of each video transmission line. HD-TVI systems require the use of dedicated transformers (baluns) that are capable of operation in a broader frequency band compared with "classic" systems transmitting CVBS signals.

The example of an HD-TVI video balun is Etrix M16654. In the case of a UTP/FTP cat. 5 cable,
the transmission line can reach 170 meters (signals from HD-TVI, HDCVI, AHD cameras)
or 400 meters (signals from CVBS cameras).

Saving and loading lists of license plates for the DS-2CD4A25FWD-IZS camera.

The Lightfighter DS-2CD4A25FWD-IZS K17891 camera can be used for license plate recognition (LPR) and control (via alarm output) of a boom gate to a housing development, without a need for a DVR. In the case of the autonomous operation, it is necessary to import the list with "white" (allowed) and "black" (prohibited) license plates/vehicles. Such a solution can automate the control of the access to the development. The installer/administrator can edit the list after logging on to the camera and going to Configuration -> Advanced Configuration -> Road Traffic -> Blacklist & Whitelist submenu. The Export tab enables the user to export the current list (with *.xls extension) to a computer (to save it on the hard drive). Then, it is possible to change and enter the suitable data in every three cells of each item (row) on the list. In the autonomic mode the list can have up to 2048 rows.

After updating and saving the list, it is necessary to go again to the Configuration -> Advanced Configuration -> Road Traffic -> Blacklist & Whitelist submenu. The next step is to click the Browse button and indicate the location of the saved file, then click the Import button to transfer the file to the camera. The last step of the configuration procedure is made in the Configuration -> Advanced Configuration -> Detection Configuration menu (activation of license plate recognition, selection of the detection area, arrangement of a schedule, choice of the reaction to the appearance of a white-listed or a black-listed car - the state of the alarm output).

Launch (building) amplifiers in MATV/CATV systems.

Building amplifiers belong to the main components of MATV and CATV systems. Their main function is to strengthen RF signals to the levels necessary for distribution networks based on coaxial cabling and passive components (splitters, taps, outlets). In the case of MATV systems distributing DVB-T programming, the amplifiers should ensure one-way transmission to the users' outlets (forward path), whereas CATV networks usually use two-way devices with return channel (forward and return path), which can provide subscribers with triple play services (TV, Internet and telephone).

TERRA company is a leading European manufacturer of broadband amplifiers. It offers a wide range of standardized products, as well as can provide customized solutions to meet specific requirements of customers.

The high-power building amplifier HS-200 R82309 is designed to amplify FM radio and TV signals in the VHF and UHF bands (split-band structure). The maximum gain is 43-49 dB in the 47-422 MHz range (maximum output level of 118 dBμV) and 49-56 dB in the 470-790 MHz range (maximum output level of 121 dBµV).

TERRA broadband building amplifiers:

Wireless "ON/OFF" control.

The RWG-01 F5224 remotely controlled power outlet can switch on/off power for any electrical appliances with 230 VAC rated voltage and power consumption below 4000 VA. The outlet can be wirelessly controlled by any remotes from the EXTA FREE system. There is no need for any installation - the RWG-01 is plugged in directly into a normal AC power outlet, in series with the appliance.

Key features of the outlet:

• Works with EXTA FREE remote controls (wireless transmitters)
• Controls of any connected AC appliances, e.g. lamps, heaters etc.
• Plugged directly into a normal 230 VAC outlet
• 5 operation modes: switching on, switching off, monostable mode, bistable mode, time mode (delay of switching off)
• Long reception range (up to 300 m)
• Optical indication of operation
• Low power consumption, possibility of continuous operation

Joining pigtails and fibers of different types/standards.

The experience of installers shows that different types of fibers cannot be spliced in an arbitrary manner. Generally, the whole transmission link should use the fibers of the same specification, e.g. G.652.D, G.657.A1 etc. However, it often happens that the installer does not know in advance what type of fibers is provided to the distribution frame/box.

It is possible to splice cables with G.657.A1 fibers with pigtails with A2 fibers. The reverse connections (A2 fibers in the cable, A1 pigtails) have much worse performance. The still most popular G.652.D fibers should not be spliced with G657.A2 pigtails, but can be joined with G657.A1 pigtails.

It is worth mentioning that the information is not a presentation of any standards or guidelines, but only some conclusions from the experience of installers splicing optical fibers. It is possible that some models of welding machines will allow for satisfactory results with theoretically incorrect combinations. On the other side, the universal and always legitimate approach is keeping one standard of fibers in the whole installation.

FTTH - the use of universal and indoor cables. Buildings are usually connected to fiber-optic infrastructure via universal cables, gel-filled and with jackets resistant to UV radiation. Despite the fact that the cables have LSOH jackets and can be installed inside buildings, the change of the kind of the optical cable at the entry to a building into an indoor version may be a good idea due to the lack of gel and easier installation... >>>more

The change of the kind of optical cable from universal to indoor is always connected with the installation of a box protecting the splices (above: Ultimode L5408)

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