Twisted-pair transmitters in engineering practice, analysis of Frequently Asked Questions

    Twisted-pair transmitters in engineering practice, analysis of Frequently Asked Questions

    1, project implementation was found: 100 meters of the control points, using pairs of passive ta-302tr when color is very pale and somewhat less interference from single-active in ta-306tr, even if the vr1 transferred to the far left, brightness, or is too high, the image pale, how to solve? A: The use of double passive device, because it does not enlarge the ability to compensate, so that transmission lines in the process of decay must rely on after-class equipment to compensate, so we have repeatedly stressed that the use of pairs of passive devices must have a post-class: brightness, contrast, color adjustment function.

The interference pattern appears, you can empty a useless cable ground handling, in general can be solved. If the wire compliance, then, even if the double passive device, 200 meters should not appear after the class notes do not come back the brightness of color decay, please check the wire

    In addition, in such a short distance from the use of a single active device when the image whitish, excluding the camera itself, causes of failure and set the signal is not normal external (with the monitor connected directly to the camera below to see, to judge), is generally As it is, after amplification the signal is too strong actions, can be ta-305r of the twisted-pair inputs, each string of a 30 Europe 1 / 2 watt resistors, and then access twisted pair signal in general can be solved

    2, the above setting causes the camera signal is not normal, the main means of electronic shutter, aperture and other settings, improper settings can cause a normal looking room, watching outdoor pale or bright areas of the image, you can refer to the camera information or to obtain vendor's technical support

    3, passive converter ta-202t / r there any direct connection bnc head?

    A: You want such a passive side to connect the camera directly, we are also available. Model is ta-201t / r, can be set directly behind the bolt head of the bnc to use, easy to use also saved a bnc head. Note that this paragraph can only be used in a fixed non-PTZ monitoring point (because the twisted-pair is not folding, always moving, then quickly disconnected a), relative terms, with the terminal connected ta-202t / r likely to adapt to a wider number of surfaces, you can work according to your actual need to use

    4, we use the actual results are: a network cable in fact can only be used where two pairs of twisted pair transmission video, even if there is another two pairs of images, the effect is very poor. You do not say there will not be the same time, four pass interference do?

    A: It should not interfere. May be that you bought from the two pairs of copper wire and two pairs of copper coated iron wire consisting of low-cost cable. As usually done when the network generally used two pairs of twisted-pair can be, so do not feel anything, but the transmission of video must be of pure copper twisted-pair, can not be used to compare those two pairs of lines, it should be relatively hard, resistance is also higher than the normal line higher. Later want to pass the video, then do not use these two, more than 300 pieces / box of cheap low-quality line of the

    5, Why do not you have made the product the way DIP switch to set the distance? Debugging will briefly point, right?

    Answer: It is indeed so, a way to use DIP switches to set gain compensation amount will simplify the debugging process. However, this approach will be the circuit's gain and the amount of compensation set in a limited number of points, so it is rarely the opportunity to meet the time line is just the status quo and make optimal state of the image effect.

The project will use our own experience confirms this, so we shape the production of external sales of products, receiver gain compensation adjustments for non-use of variable resistor to adjust the level of continuous use of adjusted multiple times, after the very images can be easily adjusted to set the dial code can not be achieved by the optimal state of the

    We believe that: monitoring the project and technical personnel, should learn a little about the image brightness, color, contrast, resolution, dispersion, color smearing, ghosting, etc. the basic concept of common sense, after careful adjustment of contrast, is entirely can be done through a long distance transmission of images, tens of meters and the 100-line transmission of video images, almost no difference between the naked eye to observe the extent.

Hope that the broad engineering users to be able to achieve lower costs, while improving the image quality results, but it also depends on the efforts of constr