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

No. 23/2023 (June 5, 2023)

Bee++ robotic bee.

Scientists have been trying for more than 30 years to construct artificial insects that can be used for various applications such as artificial pollination of flowers, search and rescue operations in confined spaces, biological research or environmental monitoring. In an era of global bee extinction, the topic seems even more relevant.
Researchers at Washington State University initially created a two-winged robot bee, but it had limited mobility. In 2019, Pérez-Arancibia and two PhD students first constructed a four-winged robot that was light enough to take to the air. To perform two manoeuvres, known as pitching and rolling, the researchers programmed the robot so that the front wings move differently to the rear wings when pitching, while the right wings move differently to the left wings when rolling. This creates a torque that causes the robot to rotate around the two main horizontal axes.
An animation showing a small robotic bee in flight. The robot is equipped with four wings made of carbon fibre and mylar and four lightweight actuators controlling each wing. The Bee++ prototype is the first to fly stably in all directions.
Controlling the complex rotational motion is extremely important because without it, robots become unstable and crash. For many years, people have had different ideas on how to control rotation, but no one has been able to achieve this due to limitations in propulsion. To enable controlled turning of the robot, the researchers took inspiration from insects and programmed the wings to move in a plane at an angle. They also increased the number of wing strokes per second from 100 to 160. The mechanics and drive controller were also changed.
The Bee++ robot weighs 0.95 g and the wings have a wingspan of 33 mm. The weight of a live bee is about 0.2 g. Unlike real insects, Bee++ can only fly autonomously for about five minutes (due to power limitations). Researchers are also developing other types of insect robots, including crawlers and robots that walk on the surface of water.

Fibre optics – why is measurement at 1310 nm not enough?

The figures below show the results of a reflectometric measurement of a 150 m section of fibre optic cable connected to a runner of the same length. The measurement was performed for the 1310 nm wavelength – here the measurement showed no anomalies, and for the 1550 nm wavelength – here increased attenuation was noted at 75 metres (225 metres including the run-up fibre).
Reflectogram 150 m + 150 m – wavelengths 1310 nm and 1550 nm. For the 1550 nm wavelength, fibre bending is visible.
Magnification of the graph in the vicinity of the event (225 m).
The attenuation of the event for the 1550 nm wavelength was 0.325 dB. Since for 1310 nm the event is not visible, it is most likely that the event is a so-called macro fibre bend.
The above event tables show the measurement results for both wavelengths. Note that the second table (1550 nm) shows an event identified as a splice with an attenuation of 0.325 dB. This is in fact a fibre bend – not visible in the first event table (1310 nm). Furthermore, it can be seen that measurements at both wavelengths generate different results in the context of events such as splices. As an example here, event number 2 is an uncleared connector with an attenuation of 0.415 dB for 1310 nm and 0.999 dB for 1550m.

Measuring the DVB-S/S2 satellite signal with

To ensure proper reception of satellite TV, many people, who are afraid of setting up and installing a satellite dish on their own, use the services of an expert. In fact, this is not a simple task for an inexperienced DIY enthusiast, and the proper adjustment of the antenna dish has a key impact on the quality of satellite signal reception. If the satellite signal is supplied to several receivers, multiswitches are used, to which cables from a quatro LNB should be connected. Such system requires 4 cables to be connected. An ideal solution in such a situation is to use the Signal ST-5150 R10842 meter.
The video above shows how to set up a satellite dish with quatro LNB A98257 using Signal WS-6980 R10842 meter for Hotbird 13°E satellite. The dish should be mounted on the south, southeast, or southwest wall of the building. The south direction can be found using a compass or design plans of the building. Depending on the geographical location, the elevation angle (the angle of deviation of the antenna from the vertical) of the antenna should be determined. In Poland, it varies from 27° in the north to 33° in the south. Then the connect 75 ohm coaxial cable to VL output of the LNB A98257 and the R10842 meter. Signal measurement with the meter and final setting of the antenna consists in correction of the dish position based on the meter readings. After “finding” the satellite signal and tightening all screws, rotate the LNB to achieve the best possible signal quality.

VLAN usage in CCTV systems.

The same IP network should not simultaneously contain devices responsible for home security (monitoring, intercom, gate controllers, etc.) and home computer equipment. Separating these devices is one of the factors increasing integrity of the security system.
A way to separate these networks is to create virtual local networks. This requires the use of a managed switch and creation of dedicated VLANs. In the example below, by changing parameters on the switch, the user can create two separate networks. The first one will cover monitoring, and the second the home network. Both networks operate independently.
It is very important during configuration (and often neglected) to manually assign IP addresses to the devices, without specifying a default gateway. Devices for securing the house should not have direct access to the Internet. Also remember to disable any cloud-based services (e.g. remote viewing). The administrator should only allow access to the internal network from the outside using a VPN (of course, this involves the need for an external IP address).
An example of an IP network with VLANs

New products offered by DIPOL

Fiber optic coupler: GFP-12F-T-2, 4 inputs/outputs with a 12F tray
The GFP-12F-T-2 fibre optic coupler, 4 inputs/outputs with a 12F tray L56038 allows to make a fibre optic connection including up to 12 splices. Flat design allows it to be used in locations with limited space. The housing is made of polypropylene (PP), which guarantees resistance to UV radiation, low and high temperatures, and substances found in telecom ducting.

Fiber optic coupler: GFP-6P, for DAC cables, 2 inputs/outputs with a 6F tray
The GFP-6P fibre optic coupler for DAC cables, 2 inputs/outputs with tray 6F L56060 can be used in ground systems as a repair element or connector for DAC cables with a maximum of 12 fibres. The coupler has a built-in splice holder with a capacity of 6 splices. With a two-row casing arrangement, 12 splices can be accommodated.

Fiber optic coupler: GFP-8E, 3 inputs, 8 outputs
GFP-8E fibre optic coupler, 3 inputs, 8 outputs The L56083 is a box-type coupler equipped with 11(12) inlet/outlet ports. This type of a joint box is used to protect fiber optic cable strands and branching systems in overhead and wall-mounted installations. Quality polycarbonate (PC) housing is resistant to UV radiation, low (-40°C) and high (+ 60°C) temperatures , and chemicals, which makes it suitable for overhead, ducting and buried cable systems.

Worth reading

Radial multiswitch system. multiswitches from the TERRA MR series have up to 32 outputs and therefore allow building systems with up to 32 outlets on a single device. Such a TV network ensures trouble-free distribution of digital signals, both in DVB-S/S2 standard (satellite) and DVB-T2 standard (digital terrestrial TV). Such networks, known as radial or star networks, are the simplest type of system and generally do not require prior design. However, to be safe, a signal attenuation balance should be performed for the shortest and longest signal paths...>>>more
The above shows a TV/SAT system with 8-output multiswitch MR-508 R70608.70608.
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