In is holding 2010 Shanghai worlds on abundant, Shenzhen superior tetraethyl pyrophosphate science and technology is very honored is the World Expo multimedia informations released that the system has provided specialized, highly effective, the environmental protection transmission plan - - twisted pair line transmission, it by the fine transmission effect, simple installed safeguarding as well as the extremely high performance-to-price ratio has won the consistent high praise from all walks of life with the appreciation. Below we under understanding this wrap transmission plan.
This session of World Expo attract worldwide attention in the Chinese hall has a landscape is " the sightseeing bus sightseeing ", sits may understand from ancient times till now some architectural style change as well as the millennium culture evolution on the vehicle, including the botanical garden area, bridge area and so on. Waits for the tour in the tourist the line area, is composed of 16 large-scale liquid crystal boxes, released that in the facility some simple introductions and the design idea, let the tourist be clear, the feeling is clear.
In Wan in Ke the tube, the boundless atmosphere's projection background, the fresh careful exhibition hall introduced that the tall and pleasing to the eye suspended ceiling phantom as well as the grand broad big screen theater draws support from the specialized reliable VGA transmitter to implement, through the ordinariest twisted pair line the high quality image long-distance transmission, lets the most careful primitive picture development in front of the tourist.
In the World Expo so high specification's grand meeting, why do many important facilities use the VGA twisted pair line transmission mode to take the propaganda method in abundance, and has made the so pleasant image progress? Thus it can be seen, the twisted pair line transmission technology undergoes many year temperance and the practice, technically already achieved a brand-new altitude, it not can only achieve transmits the high standard image signal requirement, moreover satisfies the current environmental protection, the energy conservation, the highly effective social subject. Why then the VGA twisted pair line extension mode can so win World Expo's favor, below we comparative analysis reason:
1st, knows the VGA signal
VGA signal: In is obviously saves the image which stores by the number format (frame) the signal to pass through in RAMDAC the analog modulation simulation high frequency signal, then outputs the screen image formation again. The VGA signal has the resolution high, the display speed quick, the color rich and so on merits, obtained the broad application in the colored monitor domain.
2nd, which transmission mode does the VGA signal have?
VGA signal-amplifier
It uses the simple enlargement principle, either enlarges the transmitting end signal, either signal enlargement which already weakened the receiving end. The mode enlarges which in the receiving end as soon as comes out to get rid, because he will transmit the disturbance to enlarge together, crosstalk including internal signal between. Uses device which the transmitting end enlarges, in uses specially makes the VGA video frequency line cable after the transmission medium, may in computer's VGA video signal transmission several dozens meters. But the people more make afterward the VGA wire rod line core are thicker, has not changed the VGA transmission technology principle the flaw to be getting more and more obvious:
First, the long distance VGA wire rod is also thick is also hard, is not easy to find, needs to arrive at the factory custom make fiercely, the corner also easy to present the internal break, the wiring is extremely inconvenient.
Second, VGA in welding time is also easy each kind of question (for example standing wave disturbance, faulty soldered joint and so on).
Third, it cannot resist the disturbance, cannot eliminate the crosstalk. The VGA wire rod itself resolved that its long distance transmits the internal crosstalk, the mold disturbance is altogether big. But along with distance adding, some are not originally the very strong disturbance also becomes inside the long distance wire rod formidable, causes under some experimental conditions to be able to succeed, but the actual project does finished simply does not have the means application, creates heavy loss which doing over or is unable to approve. Therefore surpasses 30 meter distance this mode not to use.
RGB transmission technology
The people according to the VGA signal to divide into the RGBHV five kind of signals the principles, analyzes the VGA line cable, transmits with five coaxial line cables, this transmission mode calls RGB to transmit. This mode valid solution weaken question (RGB line cable line core compared to VGA line cable simple root line core thick very many), simultaneously the coaxial line cable's shielding layer, also has certain inhibitory action to the crosstalk, but as a result of transmission technology principle not radical change, crosstalk question not true solution! Moreover after the RGB mode transmitting range achieves certain distance, because the job location conditions is complex, wiring time presents RGB five to transmit the RGBHV signal line cable length not consistently, the arrival time different phenomenon, creates the RGB tertiary color and the good field signal cannot the synchronization arrive. Above the screen has three kind of colors not to be able to superpose in is together unable, even the phenomenon which displayed. This is in the RGB transmission easy to have not the synchronized problem, this question is very difficult to obtain the inexpensive solution.
VGA twisted pair line transmission technology
In order to solve in these transmission problem, one kind uses the ordinary mesh wire (twisted pair line) is the transmission medium VGA video frequency transmission technology becomes the present VGA video frequency transmission technology rapidly the hot spot. This transmission mode uses a transmitter information clerk receiver, the transmitter carries on the VGA video signal codes transmits by the difference signal above the mesh wire, to far-end receiver decoding reduction VGA video signal. The mesh wire transmission uses the video frequency difference technology, every time transmits a signal time to the twisted pair line, is simultaneously originating the profile same, the polar reverse signal, this kind of pair of twisted pair line foreign radiation's signal on the counter-balance is zero mutually, technically solves the VGA signal internal crosstalk problem. Inside the mesh wire only then 4 pair of twisted pair lines, transmit VGA five kind of signal time with the mesh wire how to manage? The early time we divide inside VGA signal RGB 3 pair of twisted pair line transmissions, is left over one pair to transmit the HV signal, inside the mesh wire to the twisted pair line length is also dissimilar every time, is not also the existence not synchronization question? Solution: Line compensation! With the RGB line cable transmission different is: Inside the mesh wire has the international standard every time to the twisted pair line length difference, we may act according to this standard to know that to the twisted pair line line length approximate difference, carries on the line compensation every time according to this length, such VGA signal cannot solve the problem with the RGB mode also to be solved in here!
VGA twisted pair line transmission technology superiority
Uses the difference technology itself resistance to interference is strong, in addition some technical processing, the anti-jamming obtains enhances greatly. The anti-jamming is guaranteed that the high clear image transmission the important index, the different product antijamming effect is dissimilar. Take the mesh wire as the wire rod selection small advantage, a crystal manufacture is easier than VGA or the RGB line cable's welding, the wire rod is soft, the wiring is also convenient. At present the VGA video frequency extender and the VGA long-line driver price difference is not big, the distance is farther, the wire rod cost is lower, the contrast antijamming effect is better, the performance-to-price ratio is higher. The technology is progresses unceasingly, the twisted pair line transmission technology is also is progressing unceasingly! Not only we may use a mesh wire to transmit the VGA video signal, moreover can also simultaneously transmit data signals and so on mouse keyboard USB. This company has the twisted pair line transmission computer peripheral various seed grafting verbal message number technology, and has held at this aspect is in the lead.
Through the above analysis, we may understand the twisted pair line transmission mode has a better superiority. From the product antijamming, the wiring construction, the wire rod selection, the multi-purpose characteristics which the technology has and so on has the noing need for doubt superiority variously.
3rd, UTP801AT/AR applies in the Shanghai World Expo
In this session of World Expo various facilities image transmission's requirement is very high, therefore, to guarantee the image the quality, for can demonstrate fully national and the enterprise image, we use high clear VGA twisted pair line sound video frequency extender - UTP801AT/R, it is one has the long distance driving force high quality sound video signal transmission facility. Through at the same time the simple root ultra five category of non-shield's twisted pair line a group video frequency and the tonic train signaling long-distance transmission, after the transmission video frequency effect does not have trailing the double image, not, the picture limpid as in the beginning, the wire rod is good when may amount to 500 meters. This set of device interference suppression and anti-electromagnetic radiation ability is strong, both may use in each kind of disturbed condition complex conditions, and does not have the electromagnetic interference to the outside, is the suitable environmental protection product.
