No. 41/2016 (Dec. 12, 2016)
Will graphene solutions replace LCD and LED technologies?
Dutch researchers from the Delft University of Technology have discovered a new way to display color images. It is based on graphene "bubbles" changing color during the process of expansion and contraction. In its original form graphene is transparent. However, the use of a sheet composed of two graphene layers is sufficient to cause the phenomenon of color change. The graphene sheet placed over silicon with tiny cavities and locally stretched under pressure like skin on a drum was changing the color, depending on the pressure and the resulting shape of the bubbles in the cavity areas. According to the scientists, such "mechanical pixels" could one day replace conventional display technologies. The new technology could eventually lead to the production of screens that are more durable, flexible (even rolled like a sheet of paper), and above all - much more energy-efficient. The work on the new solution is at a preliminary stage and only further research can determine whether and how quickly the new technology will go into mass production.A visualization of "graphene pixel"
Graphene has become the subject of intense research since the first groundbreaking experiments that took place fifteen years ago. Currently, it seems that the material will become as important as steel and plastics. It is expected that graphene will revolutionize many industries, including electronics and biomedicine, and will bring huge economic benefits. The material consists of a single layer of carbon atoms arranged in a honeycomb crystal lattice. It conducts electricity and heat at least like metals and is transparent like glass. Graphene is extremely durable, yet very flexible, featuring 100-times greater strength than steel. A thin sheet with a thickness of food wrap could support the weight of several tons.
Measurements of DVB-T signals - Bit Error Rate (BER).
The vast majority of commercially available meters of digital television signals allows only signal level measurements expressed in dBμV and an approximate estimate of their quality (usually as a percentage). Usually, it does not allow for precise positioning of the antenna. An important parameter that should be taken into account when measuring DVB-T signals is BER. This parameter is well known to all installers of satellite dishes and describes the quality of the received signal. It informs about the proportion of erroneous bits (caused by interference occurring in the transmission channel) in relation to all transmitted bits.Most of professional measuring instruments can measure two types of BER. First of them - BER, bBER, Pre BER or channel BER - is the bit error rate measured after decoding and before Viterbi correction. From the perspective of the installer, it is the most important parameter. The second - aBER, vBER, or Post BER - after Viterbi Bit-Error-Rate is usually about 10 000 times smaller than BER. It is practically not measured during installing antenna systems.
A good quality signal features BER of 1E-4 or less. Such signal is recognized as Quasi Error Free (QEF). The measurement tool that measures all important parameters of digital signals is DVB-T/T2 & DVB-C Signal Meter Digiair PRO T/T2/C R10511.
DVB-T/T2 & DVB-C Signal Meter Digiair PRO T/T2/C R10511
Signal levels of six channels | SNR, Pre-BER, Post-BER measurements |
Digiair PRO is an indispensable tool for exact positioning of television antennas and for measuring analog TV and digital DVB-T/T2/C signals for diagnostics reasons. The biggest advantage of this meter is the ability to measure bit error rate (BER) and modulation error ratio (MER) of digital signals. These parameters are critical for proper operation of systems using digitally modulated signals. The R10511 meter enables the user to define and store in its memory up to 5 lists, each grouping 6 channels or multiplexes that are used in a certain area.
Intelligent recording redundancy increases reliability of IP CCTV systems.
The video from an IP camera is transmitted to the IP NVR in the form of data stream. In the case of a network failure or bandwidth reduction, the information is irretrievably lost, because the network does not buffer packets and the camera cannot send them again. This is the reason for the increasing popularity of IP cameras with SD/SDHC card recording option.The recording redundancy significantly increases the reliability of such systems. However, cheaper cameras with that functionality record the video streams on a continuous basis, which greatly reduces the life of the memory cards and do not ensure automatic synchronization of data.
IP CCTV system protected against failure of data transmission
The ANR (Automatic Network Replenishment) solution developed by Hikvision limits the recording on the card only to the periods of problems with connectivity between the camera and NVR. After the end of the failure, the emergency recordings are automatically transferred to the NVR. So, in the event of interruptions in the transmission, the operator of the system does not need to take any actions to complete the video footage.
Categories 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 analog telephony and Ethernet networks. Twisted-pair cables may consist of one or more pairs. The twisting strongly reduces the influence of external electromagnetic interference and mutual interference between the pairs, called crosstalk.With the increase of the required bandwidth of computer networks, twisted pair cables have to carry signals at higher and higher frequencies. Thus, there is a number of categories to standardize parameters of the cables. The differences consist mainly in the dimensions of the wires, precision and stability of the cable structure, shielding.
TIA/EIA 568A standard | ISO 11801 EN50173 | Connectors | Application | Band |
Cat. 1 | Class A | Telephone services | up to 100 kHz | |
Cat. 2 | Class B | Voice services and older terminal systems | up to 1 MHz | |
Cat. 3 | Class C | RJ11 RJ12 RJ45 | 10BASE-T Ethernet, telephone cables | up to 16 MHz |
Cat. 4 | - | RJ45 | 16 Mbps Token Ring | up to 20 MHz |
Cat. 5/5e | Class D | RJ45 | FastEthernet 100Base-TX, GigabitEthernet 1000Base-T | up to 100 MHz |
Cat. 6 | Class E | RJ45 | ATM622, GigabitEthernet 1000Base-T | up to 250 MHz |
Cat. 6A | Class EA | RJ45 | GigabitEthernet, 10-GigabitEthernet 10GBase-T | up to 500 MHz |
Cat. 7 | F | GG45, TERA | 10GBase-T, transmission of HD video, 3-play services | up to 600 MHz |
Cat. 7A | FA | GG45, TERA | 10GBase-T, CATV up to 862 MHz, 3-play services, ready for 40G, ready for 100G | up to 1 GHz |
Fiber optic connection for cameras on a pole.
IP cameras located on a pole can be connected to industrial switch via outdoor twisted-pair cable NETSET E1412. The Ultipower 124P N29973 switch also acts as an Ethernet to fiber media converter and PoE power supply for the cameras. In turn, the switch is powered by the Industrial Power Supply N93326 connected to AC power network (100-240 VAC). The switch is connected with the fiber optic system via two SC-LC L3215 patch cords.Components of the implementation of a junction point in weatherproof box installed on a pole, which can provide a ready-made solution for many applications:
- R90603 - Waterproof Installation Box (250/310/145 mm, IP55)
- R90610D - Pole Mount (2 brackets)
- N29973 - Industrial PoE Switch ULTIPOWER 124P-4POE-20
- N93326 - Industrial Power Supply Mean Well MDR-60-48
- L5402 - Distribution/Termination Box ULTIMODE TB-02B (IP65)
- L3555 - Single-mode Pigtail ULTIMODE PG-55S (1xLC, 9/125) - 2 pcs.
- L4355 - Single-mode Adapter ULTIMODE A-555D (2xLC to 2xLC)
- L3215 - Single-mode Patch Cord ULTIMODE PC-515S (1xSC-1xLC, 9/125) - 2 pcs.
- E1412_1 - Cat 5e UTP Cable NETSET U/UTP PE (outdoor)
- L76004 - Universal Cable: ULTIMODE UNI-4SM-A (4xG.652.D)
The L76004 optical cable with four fibers enters the R90603 box and the L5402 distribution/termination box. The fibers are laid in several loops for the formation of a cable reserve, in case one needs to take the L5402 box outside. Two of them are spliced with L3555 pigtails (LC) with the use of the L5810 fusion splicer and L5554 heat-shrinkable protective tubes. Their LC connectors are plugged into the 2xLC to 2xLC L4355 single-mode adapter.
Independent HDMI and VGA outputs in Hikvision NVRs from the "I" series.
Hikvision NVRs from DS-76xxNI-I2 and DS-77xxNI-I4 series have been equipped with independently configured HDMI and VGA outputs. Each of them can provide different video stream and screen divisions with images from any cameras connected to the NVR. The displaying parameters can be setup in the System->System Settings->Configuration->Menu Output window. The maximum resolution of the HDMI output is 4K (3840x2160 pixels), and of the VGA output is Full HD (1920x1080 pixels).Setting up HDMI and VGA output resolutions in DS-7608NI-I2 K22083 NVR
FM-VHF/UHF Antenna Diplexer/Combiner Telmor ZWR-210DC C0325 is a masthead diplexer used for combining signals from two antennas, FM/VHF (5-230 MHz) and UHF (470-790 MHz). With the splash-proof box, it can be placed close to the antennas, directly on the antenna mast. | ||
Metal Housing/Box: TPR-23p+w (600x400x200mm, with fan) R90567 is a surface-mount housing for indoor applications, used in antenna, alarm, Ethernet systems for protecting various devices employed in the systems. | ||
4K IP NVR: Hikvision DS-7608NI-I2/8P K22086 is a modern IP network video recorder capable of monitoring, recording and playing back images from 8 IP cameras of megapixel resolutions, up to 12 MP. This model has been equipped with switch with 8 PoE ports for connecting and powering IP cameras. Its independent VGA (up to 1080p) and HDMI (up to 4K) monitor outputs can provide images with different layouts. Each monitor can display the video from any camera, in any screen division. | ||
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Transmission of HD video (HDMI) from a DVR/NVR over a long distance. The DVR/NVR that records the video surveillance data is often located in a safe place, distant from the surveillance room with the monitor(s). This implies the need to send the video signal (most frequently HDMI) from the video recorder over the long distance, of tens and sometimes even hundreds of meters... >>>more
Transmission of HDMI video with the use of Signal-HD H3608 converter and optical link