DIPOL Weekly Review – TV and SAT TV, CCTV, WLAN

Historic landing on an asteroid.

On October 20, NASA successfully completed another mission. For the first time in NASA history, the OSIRIS-REx probe collected a sample from Bennu asteroid (more than 321 million kilometers distant from the Earth). The head of NASA has acknowledged that it is the largest sample of space rocks that will be delivered to Earth since the lunar Apollo missions. It is worth adding that NASA is not the first agency in history to accomplish such a mission. In 2010, the Japanese space agency JAXA took samples from Itokawa asteroid.

The descent alone onto Bennu lasted about 4.5 hours. While landing, the probe extended an 11-meter arm that collected dust and rock covering the surface of the asteroid in an operation that took just 6 seconds. The probe is expected to return with the samples in September 2023. The samples collected may hold clues as to how water, and thus life, originated on Earth.

Video of the Touch-And-Go (TAG) operation of the OSIRIS-REx probe

According to scientists, Bennu was formed about 4.5 billion years ago, which is about the time when the Solar System came into existence. Bennu is considered a near-Earth asteroid - the risk of collision with our planet is estimated to be 1: 2700.

Advantages of fiber optic cabling in SMATV systems.

Originally located on the roofs of buildings, the SMATV systems are particularly prone to surges caused by lightning. In spite of proper grounding of all system components, some devices suffer irreparable damage. It has to be stressed that not only the system devices alone are exposed to surges, but, in extreme cases, the subscriber equipment, such as satellite receivers or TV sets, are also affected. Fiber optic cable provides excellent surge insulation. This means that any electric charges induced near the antennas will stop at the very downstream optical transmitter, so the remaining components of the system are 100% protected.

Optical fiber cables are safe to be placed together with copper cabling for transmission of other signals or power (100% resistance to electromagnetic interference). The diagram below shows an example of an optical-copper cabling that enables the transmission of TV/SAT signals.

Protecting a single mechanical splice.

L5550 mechanical splices are often used in IP surveillance systems. The signal from an IP camera is sent to the media converter, and then transmitted via optical fiber to the DVR. The installers mostly want to save as much space as possible in junction boxes next to the cameras. Covers of mechanical splices might be of help, which, with the cables and pigtails being worked on properly, allow to eliminate the need for much larger junction boxes.

Cost effective monitoring using Hikvision IP EasyIP Lite series cameras.

The diagram below shows an IP CCTV monitoring system based on Hikvision cameras and a DVR. EasyIP Lite series cameras are used in the monitoring system. This series is distinct for good image quality and affordable pricing. Basic alarm events, such as motion detection or image tampering, are supported. 2 MP cameras with a focal length of 2.8 mm and an IR illuminator up to 30 m based on the EXIR 2.0 technology are installed in the facility. For outdoor use, the DS-2CD1023G0-I K17661 cameras are recommended, and for indoor installation, the DS-2CD1123G0-I K17262 ceiling cameras are the right option. The Seagate SkyHawk 2 TB M89271 hard drive used in the recorder ensures the storage of recordings with continuous recording from all cameras for 11 days when using H.265 compression (2 MP @ 25 fps, 2 Mbps). The entire system is powered by the PoE N299851 switch. An 8-channel Hikvision DS-7608NI-K2 K22074 IP DVR is used to record the image. To enable access to the recorder via Internet or Wi-Fi, you can connect a router to the system, e.g. the TP-Link C2 AC900 N3255.

IP CCTV system based on EasyIP Lite cameras

Basics of IP addressing – part 6.

The previous issue discussed the details of network ports. Another important parameter is the DNS. To change public (external) IP addresses from numeric to a domain format, the DNS (Domain Name System) service is used. Hence, there is no need to remember the addresses e.g. in the 62.121.130.38 format, but just a much more friendly www.dipolnet.com instead.

Translation of the domain name into the set of numbers is performed by the appropriate DNS server, to which the computer sends a request for the translation of the address. After receiving the response with the numeric address, the computer connects to the relevant computer/server.

The DDNS will be discussed in detail in the following issue of this Weekly Review.

Advanced motion detection configuration.

Hikvision IP cameras (except for some design devices) can define 8 independent motion detection zones, where each zone can have different sensitivity and detect objects of different sizes. This can avoid problems which may be caused by moving parts of the scene (e.g. leaves and branches moved by the wind), then the sensitivity in this zone should be reduced. Moreover, detection parameters can be different in each zone for day and night modes. In night mode, cameras often generate noise that can be recognized as motion by analytical algorithms. Therefore, it is recommended to reduce the sensitivity of motion detection in the night mode.

The settings mentioned are available after selecting an advanced configuration option of motion detection.

Advanced motion detection configuration panel

HD-TVI cameras in a TV system. Converting the A/V signal from computers, players or CCTV cameras etc., into high-frequency RF signal used in terrestrial television systems requires the use of a modulator. The device is equipped with ...>>>more

Using the MI520P IP - 2xDVB-T R81609 modulator

Hik-Pro Connect - new platform for installers and integrators