传输系统出现故障的分析与解决方法

1、传输系统出现故障的分析与解决方法it was a loss of gold. several early warblers contend for a warm tree. in this nocturnal music, there is no one who can't afford the garden sima zhao, s heart is known to everyone heaven and earth are old, and the world is a vicissitude analysis and solution of failure of transmi

2、ssion systemthe transmission system for tv monitoring, commonly used, is the video transmission. limited to space, this paper analyzes the failure phenomenon of video transmission and puts forward some solutions.in a and video transmission, the most common failures are over 50 weeks the form of pres

3、entation is a black bar or white bar that appears on the monitor, and rolls up or dow n si owl y. this phenomenon is caused by a system that produces a bad road and introduces 50 weeks of interference from the currentneed to mention is that sometimes due to the camera or performanee of the control h

4、ost (matrix switcher) bad (or partial damage) will also appear this kind of breakdown phenomenon (sometimes there will be two black bar or white bar), therefore, on the analysis of this kind of failure occurs, to distinguish between two different reasons for failurewant to distinguish is the problem

5、 of power supply or ground loop problem, a simple method is, on the control of the host, only to the nearest access to a camera output signal power is no problem, if the interference phenomenon did not appear on the monitors, then control the host without problem. the next available nearby a portabl

6、e monitor in front the camera video output, dnd running a camera check them one by one, in order to search for the interference caused by power supply problems of the camera if so, do it. if not, the disturbance is caused by other causes such as earth ring road.b, the presence of the wooden pattern

7、interference on the monitor this interference occurs when the normal image is not submerged in light, and the image is unable to view (and even the synchronization) when it is serious the causes of this failure are more and more complex. there are several reasons for this:the quality of the video tr

8、ansmission line is not good, especially the shielding performance poor (the screen is not a good copper wire network, or the screen is too thin to block) at the same time, the line resistance of the video line is too large, and the resulting attenuation of the signal is also the cause of the fault i

9、n addition, this kind of video line characteristic impedance is not 75 q, as well as the distribution parameters within the prescribed is one of the causes of failureit is difficult to judge the cause of this fault, and because it is finished (the wiring is finished), it is difficult to solve the pr

10、oblem by changing lines therefore, the standard and required video cable must be guaranteed in advance don，t buy a bad video cable because you want to save moneysince the above interference phenomenon is not necessarily the failure of the video line, the judgment is accurate and prudent only when ot

11、her possibilities are ruled out can you consider the negative aspects of video. judgment method is that after rule out other possible causes of the failure, conditional word, the rest of this video cable (if no rest, had to intercept in the system for a period of such cable) sent to the inspection d

12、epartment to check when the test results are not satisfactory, the quality of the cable is determined if that's the cable quality problem, the best thing to do, of course, is to replace all of the cable, switch to conform to the requirements of the cable, this is the best way to solve the proble

13、m completely.under the condition of the interference is not very serious, you can try to clean by power supply, ups online connection to the entire system power supply way, often can reduce or basic elimination of interference but this approach is sometimes not obvious or sometimes useful, sometimes

14、 useful, because of the spatial signals around the systemthe power supply is not "clean the power that is referred to here is not "clean", which means that there is an interference signal on the normal power supply (50 weeks of sine wave) and the jamming signals from the power supply

15、come from the use of silicon-controlled devices in the gridin particular, large current, high-voltage, thyristor devices, which are very polluted to the grid, cause the power supply in the same grid to not be "clean such as the power grid has high power thyristor frequency modulation speed cont

16、rol device, silicon controlled rectifier device, scr ac/dc conversion device, etc,will produce pollution to the power supply.the solution for this is simple, as long as the entire system is cleansed or online ups is available.there is a strong disturbanee source near the system this can be judged by

17、 investigation and understanding. if this is the case, the solution is to enhance the camera，s shielding and to ground the pipes of the video cablec, the fault caused by the short circuit and circuit breakers of the video cable manifestation of this fault is produced on the monitor disorderly moire,

18、 large area of deep and all images are destroyed, not form images and synchronous signals this occurs more often in bnc connectors or other types of video connectors you can solve the problem by checking the joints one by onesuch fault phenomenon and it is easy to judge, namely the failure phenomeno

19、n occurs, often is not the who1e system of multiple signals are a problem, but only appear in the joint bad ' way.d, the fault phenomenon caused by the mismatch of the characteristic impedanee of the transmission line manifestation of this phenomenon is the monitor screen is produced by several

20、equal spacing bar interference, the frequency of the jamming signal is basically integer times the line frequency this is due to the nature of video transmission line impedance is not 75 q caused due to impedance mismatch if viewed with oscilloscope is jamming waveform of the image, will find good s

21、ynchronization head shoulder, after superposition has higher horizontal frequency harmonic oscillation waveform amplitude, interference is causedthrough the analysis of the waveform and quantitative measurement of video cable, also found that the impedance is not in conformity with the requirements

22、of video cables, its distribution parameter is not in conformity with the requirements, in fact this is also one of the reasons that the impedance mismatch therefore, it is also possible to say that this interference is caused by the fact that the properties of the video cable are not matched by the

23、 properties of the negative and the distributed parameters the solution of this problem is to solve it by means of "'starting and cormecting resistance" or z，terminal resistance here it is important to note that in the video transmission distance is very short time (usually within 150

24、meters), using the impedance mismatch and distribution parameter of the video cable will not necessarily appear afore-mentioned interference phenomenon therefore, in a system that is very close to the distance of the transmission distance, do not be confused by the short distance and no interference in the analysis of this fault phenomenon.the fundamental solution to the above problem is to ensure the quality of the video cable check the cable when necessary.e, the space radiation interfere