TV-SAT, CCTV, WLAN Dipol Weekly Review

Spectrometer with size of a grain of sand.

Researchers at the University of California, Davis, have developed a spectrometer occupying a surface area of only about 0.4 mm², capable of analysing light over a wide spectral range, including both visible wavelengths and the near infrared. The miniature device is designed for integration into portable devices. Instead of physically separating light into a spectrum, the system relies on its computational reconstruction, allowing it to replace classical optical elements such as prisms or diffraction gratings with a completely different measurement approach.

The key change is to move away from physical light splitting. Instead, the system uses a set of miniature silicon detectors, each of which reacts slightly differently to incident radiation. A single detector does not provide complete information, but a set of such detectors generates a complex signal that contains a coded spectrum. Only at the computational stage is it reconstructed.
A major problem with classical silicon detectors was their low sensitivity in the near-infrared range, which is of great importance in biomedical and environmental applications. In the new solution, this limitation has been overcome through the use of special surface nanostructures, referred to as photon-capture structures. Instead of passing light through a thin layer of silicon, these structures cause light to scatter and 'trap' it multiple times inside the material, significantly increasing the probability of absorption. This makes even very thin detectors effective at wavelengths that were previously difficult for them to detect.
As the signal from the detectors is not in the form of a directly readable spectrum, artificial intelligence plays a key role. The neural network used learns the relationship between the detectors' response and the actual light spectrum and is able to reproduce it with high accuracy, even in the presence of noise. In practice, this means that the system solves the so-called inverse problem - instead of predicting the signal from a known spectrum, it reconstructs the spectrum based on the measurements. This approach achieves resolution in the order of a few nanometres and stable operation under conditions that would be problematic for traditional miniature systems.

The importance of this technology goes far beyond miniaturisation alone. The ability to perform advanced spectral analysis in real time and outside the laboratory opens the way to new applications, from medical diagnostics and environmental monitoring to food quality control or integration into consumer electronics. In practice, this means that tools that have so far been available mainly in specialised laboratories could find their way into users' pockets in the near future, changing the way we analyse the world around us.

Transmission windows in optical fibre systems.

Data transmission in optical fibre takes place within a transmission window(s), selected from three (and in advanced systems four or five) bands. These have been determined in a non-accidental manner. Their selection took into account the signal attenuation characteristics of this transmission medium.

There are three main causes of signal attenuation in optical fibers:

Individual transmission techniques are implemented in specific telecom windows, e.g. DWDM multiplexing technique mainly uses the third and fourth windows. Thanks to technological advances in the production of optical fibers, it was possible to reduce the effect of OH- ions in the vicinity of the 1400 nm wavelength (G.652D fiber) and create another, the fifth transmission window.

Basics of IP addressing - part 5: network ports.

A protocol port or protocol port number is a term related to the TCP/IP protocol. They are used on the Internet to distinguish between services and connections. Protocol ports are denoted by integers in the range 1 to 65535. Some ports (1 to 1023) are reserved for standard services, e.g:

With the port number, it is possible to identify not only the processes, but also well-known services running on distant systems, so it can be considered as a service identifier. For example, if a host is also a web server, it has to open the port 80 when web resources have to be shared with another host.

SIGNAL PROfessional multiswitches MS-5/9xx.

SIGNAL PROfessional multiswitches are advanced devices designed for distributing RTV/SAT signals in individual and community installations. They are used both in one-family houses and in multi-family or commercial buildings, where stable and uniform distribution of TV and radio signals is required. The key feature of SIGNAL PROfessional multiswitches is the possibility of simultaneous transmission of signals from satellite dishes (from a quatro converter) and terrestrial DVB-T2 and FM/DAB+ radio signals to multiple subscriber outlets. An important element of the SIGNAL PROfessional series is the pass-through (cascadable) design, which makes it possible to combine many devices into larger distribution systems. As a result, these multiswitches are used in extended community installations where it is necessary to scale the network without losing signal quality.

Name	MS-508	MS-916	MS-924	MS-932
Code	R69508	R69916	R69924	R69932
Shielding class	A
Housing	Zinc-aluminum alloy casting
Input	SAT A + Radio/DVB-T2	SAT A + SAT B + Radio/DVB-T2
Number of inputs	5	9
Number of outputs	8	16	24	32
Dimensions [mm]	155x145x30	225x200x30	310x205x30	385x210x30
Type	Pass-through or terminal (mounting resistorsów with DC interlock)
Purpose	Small and medium-sized buildings	Multi-family buildings
Guarantee	4 years

The devices in this class are also distinguished by their high technical parameters - very good impedance matching, high class shielding (Class A) and a robust cast housing for resistance to interference and durability in service. Many models also feature external power supplies and LED signalling for easy diagnostics of the installation. SIGNAL PRO multiswitches are professional solutions for installers and designers of RTV-SAT systems, combining high quality workmanship, flexibility of configuration and the possibility of expanding the installation. As a result, they are widely used in modern TV signal distribution systems.

Using relay outputs in Hikvision's DS-KH6320-WTE1 IP video door entry monitor.

When installing a video door entry system, there is sometimes a need to install additional signalling to inform the user that someone has pressed the call button at the door station. An example of this could be installing the system on a noisy shop floor, being used by a hearing impaired person, or wanting to install signalling outside the house so that when you are in the garden you realise someone has arrived.

The DS-KH6320-WTE1 video-intercom monitor has two built-in relays that can be activated when the monitor starts ringing after the call button is pressed. These relays can operate in monostable (1-180 s) or bistable mode. The operating time and mode of each relay can be configured individually. For example, one relay can be connected to an buzzer with an operating time of 5 s and another to a visual indicator with an operating time of 60 s. Pairing the relays with a call button can be done using the iVMS-4200 application, after entering the remote settings of the monitor in the tab: Intercom -> Calling Linkage. Select the Enable option and choose the relay output that will be activated at the moment of calling. The relay mode and time setting can be configured directly from the monitor.

GreenPower UPS technology - how does it work and why does it save energy?

CyberPower has developed and patented GreenPower UPS technology, which significantly improves the efficiency of uninterruptible power supplies, reduces energy consumption and reduces heat generation. This enables users to reduce operating costs by up to 93% compared to conventional UPS systems.

The patented switch and dual charger system play a key role in the operation. In traditional line-interactive UPSs, the battery is continuously recharged, even when it has reached full capacity. This leads to continuous power consumption, more heat emission and faster battery wear. CyberPower eliminates this problem by automatically disconnecting the fast charger when the battery is fully charged. In practice, this means that the UPS only uses as much energy as is actually needed, significantly improving its energy efficiency. Less heat generated also translates into longer life for both the electronics and the battery itself.

The energy efficiency of GreenPower UPS technology was confirmed in comparative tests carried out on CyberPower UT series units, which showed a clear reduction in energy consumption compared to models from other manufacturers. The test procedures and test environment were verified by the independent SGS unit, further confirming the reliability of the results. The full SGS report can be viewed on the manufacturer's website.

Hikvision 2-Wire IP video intercom system. Often there is a need to replace an existing (video) intercom system with a newer one that offers greater capabilities. This type of upgrade may require the replacement of cabling, for example to twisted pair in the case of IP systems. A Hikvision video intercom operating in the 2-wire standard, so-called 2-Wire IP, which has the same functionality as the Hikvision 2nd generation IP video intercom, comes to the rescue here. The construction of a small system consists in connecting monitors (e.g. G74019 DS-KH6320Y-WTE2) and the main module of the door station ( G73646 DS-KD8003Y-IME2) to the G74824 DS-KAD706Y distributor via a 2-wire bus (2-Wire). The 2-Wire bus allows the devices to be powered and communication to be established...>>> more