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No. 3/2018 (Jan. 15, 2018)
A revolution in optics - new lenses.
In the field of optics there may soon be revolutionary changes thanks to so-called "metalens" developed by scientists from Harvard University. They have created the first single lens that can focus the whole spectrum of visible light. In conventional optics, that is only possible due to the proper arrangement of many lenses. The new lens is a construction that uses nanotechnology and metamaterials. It consists of a layer of quartz with another layer composed of millions of microscopic fins made of titanium dioxide, whose length (height) is only 600 nm. These fins are arranged in appropriate patterns, each of which breaks a different length of light. The reconstruction of the standard lens action therefore consists in creating the right patterns, determining the right orientation and the distance between them. By using pairs of nanofins responsible for specific wavelengths, the scientists are able to regulate the whole spectrum of visible light simultaneously. The coupled structures allow manipulation of wave speeds of different lengths (colors), which naturally propagate in the same medium at different rates (chromatic aberration) and thus concentration of them all in one point.
Metalens - a new type of small size lens
According to the researchers, the lenses made in this way can be thinner than the human hair and may allow up to 170-fold magnification of the image. They are free from optical defects such as distortion and can be manufactured in almost any size at low production costs. This technology can be applied for lenses used in microscopes, contact lenses, video and photo cameras, and many more optical devices.
What is the maximum PoC transmission range?
PoC, Power over Coax, is a power supply system used to energize HD-TVI cameras over the same coaxial cables that transmit video signals from the cameras to the DVR. This method of remote power supply eliminates the need for additional cables/wires - each camera is connected to the system via a single coax, or optionally, via a pair of wires from (F)/UTP cable (min. cat.5e). A decent transmission range is guaranteed by the application of high quality cables, such as Triset (coaxial) or Netset (twisted-pair cables). The diagram below shows the achievable transmission distances:
Attainable PoC transmission distances in the case of different standards and cables
Conversion of DVB-S/S2 sat TV channels to DVB-T in hotel TV systems.
Nowadays, the access to DVB-S/S2 satellite channels in hotels, motels, boarding houses etc. has become a standard service. In turn, the standard and cheapest solution is the distribution of the selected satellite channels after conversion to DVB-T COFDM digital form, along with DVB-T broadcasts. Satellite channels received by conventional DVB-T televisions can be a complement to terrestrial TV broadcasts or the main or only source of programming in the system. For this purpose, the satellite DVB-S/S2 (8PSK, QPSK) signals have to be converted to the DVB-T standard (COFDM). DIPOL offers TERRA DVB-S/S2 transmodulators that effectively perform this task and can provide a wide range of TV programming easily distributed to all rooms via typical coaxial cabling used in antenna systems, in the uniform DVB-T standard .
TDX-440 R81614 and TDX-480 R81621 modules convert (transmodulate) DVB-S/S2 (8PSK/QPSK) signals into DVB-T (COFDM) multiplexes. They should be used for reception and distribution of free-to-air channels. One TDX panel can receive signals from eight satellite transponders and create group of four neighboring DVB-T muxes (TDX-440 R81614) or two independent groups of four neighboring DVB-T muxes (TDX-480 R81621). Each mux can carry freely selected satellite channels.
We invite you to watch a video showing the configuration of the TERRA tdx-480 R81621 DVB-S/S2 (8PSK, QPSK) - DVB-T (COFDM) transmodulator.
Hikvision iVMS-4200 software specifications.
The iVMS-4200 application is a client software for the management and control of video functions of Hikvision DVRs, NVRs, IP cameras, encoders, decoders, VCA solutions, alarm hosts etc. The features of the software include live viewing and recording, remote browsing and searching of recordings, playback, backup, processing of alarm signals. A modern, intuitive interface of the application allows users to easily manage distributed small- and medium-size video surveillance systems. The table below presents basic specifications of the iVMS-4200 software (v2.7.0.6) concerning applications in (IP)/CCTV systems.
| iVMS-4200 | Service capacity/parameters |
| DVRs/NVRs | 256 |
| Groups | 256 |
| Cameras | 1024 |
| Number of cameras in a group | 256 |
| Storage servers | 16 |
| Multimedia servers | 16 |
| Decoders | 64 |
| Display (number of cameras) | 64 |
| Monitors | 4 |
| Users' accounts | 50 |
| Simultaneous playback of channels | 16 |
| Simultaneous downloading tasks | 16 |
| E-maps | 256 |
| Storage server | Write speed: 64 x 2 Mbps |
| Read speed: 64 x 2 Mbps | |
| Users: 32 | |
| Number of connected clients: 128 | |
| Streaming server | Incoming steams: 64 x 2 Mbps |
| Outgoing streams: 200 x 2 Mbps |
Optical fibers in CCTV - multimode or single-mode?
Generally, when selecting the equipment and cables, both the elements have to be compatible. If the connections between cameras and the switch are greater than 2 km, it is necessary to apply single-mode cables. Similarly to situations where one cable should transmit signals from dozens or hundreds of IP cameras. With such a wide band, the use of single-mode fibers should be a more preferred solution. The range of single-mode cables is broader, allowing for the selection of optimum cable, and the transmission line can be extended in the future beyond 2 km, if necessary.
The most popular types of optical cables used in CCTV systems are universal cables with single-mode fibers. The picture shows Ultimode UNI-4SM-A L76004.
Advantages of choosing cables with single-mode fibers:
- easier choice due to a broader range of the cables on the market
- ability to transmit signals at distances of tens of kilometers using typical equipment
- lower prices compared to multimode fibers due to lower production costs
- higher throughput capacity
- availability of cables with small bending radius, from 7.5 mm
In the case of single-mode installations, it is important to pay attention to:
- different versions of fibers may cause problems with splicing, it is recommended to unify the cables in the system
- in some cases and depending on the equipment it may be necessary to use fiber optic attenuators for short-distance links
Types and markings of twisted-pair cables.
Twisted-pair (balanced) cables are used to transmit signals in telecommunication systems and computer networks. Currently they are mainly used in Ethernet networks. Twisted-pair cables usually consist of 4 pairs of twisted insulated wires. The twisting strongly reduces the influence of external electromagnetic interference and mutual interference between the pairs, called crosstalk.![Cat5e Shielded Cable: ALANTEC F/UTP 5e [1m] (PE, outdoor, with messenger wire)](https://static.dipol.com.pl/images/en/pict/e1519_1.jpg)
Cat5e Shielded Cable ALANTEC F/UTP 5e (PE, outdoor, with messenger wire).
New item in our range of products.
New item in our range of products.
Acronyms for balanced cables are standardized by ISO/IEC 11801:2002 (Annex E). The information contained in the cable description should have the following syntax: xx/yyTP, where the letters yy characterize individual wires/pairs and the letters xx describe the overall construction of the cable.
The xx and yy markings can be as follows:
- U – unshielded
- F – foiled (screened with foil)
- S – shielded (screened with braid)
- SF – shielded and foiled
- U/UTP – unscreened cable: E1408, E1410, E1412, E1608
- F/UTP – foil screened cable: E1515, E1517, E1519
- U/FTP – unscreened cable with foil screened pairs: E1616
- F/FTP – foil screened cable with foil screened pairs
- SF/UTP – overall braid and foil screened cable with unscreened balanced elements
- S/FTP – overall braid screened cable with foil screened pairs
- SF/FTP – overall braid and foil screened cable with foil screened pairs
 | Ceiling IP Camera: Hikvision DS-2CD1141-I K17284 is dedicated for IP CCTV systems. The ceiling camera has been equipped with 4 MP 1/3" CMOS sensor providing good video coverage even in low-light conditions. Along with IR illuminator with range up to 30 m, the camera can also operate in complete darkness. The built-in 2.8 mm lens has 105° viewing angle. The IP67-rated housing of the camera protects the electronics against adverse weather conditions. The camera can be powered conventionally from a 12 VDC source or with the use of PoE option (802.3af). | |
 | HD-TVI TURBO HD 4.0 Camera: Hikvision DS-2CE56D8T-IT3ZE M75183 has been designed for use in CCTV systems based on HD-TVI DVRs. With very high sensitivity (0.005 lx) and built-in IR illuminator with range up to 40 m, the camera provides high quality 1080p video in low light or even no-light conditions (the IR illuminator made in Exir technology ensures uniform lighting of the whole observed field). 2.8-12 mm motozoom lens allows the user to set optimum viewing angle. | |
 | HD-TVI TURBO HD 4.0 Camera DS-2CE16D8T-IT3E M75666 has been designed for use in CCTV systems based on HD-TVI DVRs. With very high sensitivity (0.005 lx) and built-in IR illuminator with range up to 40 m, the camera provides high quality 1080p video in low light or even no-light conditions (the IR illuminator made in Exir technology ensures uniform lighting of the whole observed field). | |
Worth reading
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