In a computer room monitoring system into the commissioning phase, commissioning phase and after delivery, there may be such a failure phenomenon. This article describes the 12 common faults in the engine room monitoring system and how to handle them. After a monitoring system enters the commissioning phase, commissioning phase, and after delivery, there may be such failure phenomena. These failure phenomena are not normal operation, or the system does not meet the technical requirements of the design requirements, or the overall performance. And the quality is not ideal. Here are some of the more common faults that are provided to netizens for reference.
1. Incorrect equipment caused by power failure
Solution: There are several possibilities for incorrect power supply: incorrect power supply line or power supply voltage, insufficient power (or insufficient line diameter of a certain power supply line, excessive voltage drop, etc.), short circuit in the transmission line of the power supply system, and open circuit , instant overpressure and so on. In particular, the device may be damaged due to power supply errors or instantaneous overvoltage.
2. Line problem
Because some lines, especially those connected to the equipment, are not handled well, causing circuit breakers, short circuits, poor insulation between the lines, miswiring, etc. cause damage to the equipment (or components), degradation of performance, or failure of the equipment itself, but The phenomenon is reflected in the equipment or components. In particular, the quality of some connectors is poor, and the connection process is not good. This is a common cause of problems.
Solution: In this case, the analysis should be conducted calmly based on the fault phenomenon to determine which of the faults occurred on several lines due to the connection of which lines. This will reduce the scope of the problem. For example, a camera with three variable lens image signal is normal, but the lens can not control, you do not have to check the video output line, but just check the lens control line on the line. In addition, connectors, especially BNC type connectors, are very high in the welding process and the connection and installation process requirements of video cables. If they are not handled properly, even if there are no problems in the commissioning and commissioning stages, problems occur after a period of operation. It is particularly worth pointing out that cameras with pan-tilt heads have a long time due to all-round movements, resulting in disconnection and breakage of connections that are common. Therefore, special attention should be paid to the connection of equipment and various lines in this case to meet the requirements of long-term operation.
3. The quality of equipment or components itself
In general, there should be no quality problems with carefully selected commercialized equipment or components.
Workaround: Even if problems occur, they often occur after the system has been delivered and run for a long time. In addition to the quality of the product mentioned above, the most common problem is due to improper adjustment of the equipment. For example, the adjustment of the intercept after the camera is a very precise and precise job. Without careful adjustment, problems such as poor focusing or defocusing in various operations of the three-variable lenses may occur. In addition, whether the positions of some switches and adjustment knobs of the camera are correct, whether they meet the technical requirements of the system, the correctness of the encoder coding switch or other adjustable position settings directly affect the normal use of the device itself or affect the normal performance of the entire system.
4. Problems caused by incorrect connection between equipment (or parts) and equipment (or parts)
Solution: The impedance does not match. If the video is connected to a monitor with a high impedance, the image will be very bright, the characters may jitter, or sometimes there may be characters. The communication interface or communication method is incorrect. This situation often occurs between the control host and a device such as a decoder or control keyboard that has a communication control relationship. This is mostly due to the fact that the selected control host and decoder or control keyboard are not products of one manufacturer. In general, different manufacturers use different communication methods or transmission control codes. Therefore, the same manufacturer's products should be used for the host, the decoder, and the control keyboard.
Drive capacity is insufficient or exceeds the prescribed number of device connections. For example, the number of main control keyboards and sub-control keys corresponding to the control host is regulated. Exceeding the prescribed amount will cause the system to work abnormally. Decoder pan/tilt working power power is lower than the actual pan-tilt, it can not drive the PTZ.
5. The failure of the head
A pan/tilt is incapable of operation or cannot rotate at a short time after use. It is a common troubleshooting method for PTZ: In addition to the product quality factors, the appearance of this kind of situation is mainly caused by the following reasons; only the camera is allowed to be The head mounted (that is, the camera sitting on the upper part of the turntable) uses a hoisting method (ie, the camera is mounted under the turntable). In this case, the hoisting method leads to an increase in the operational load of the pan/tilt. Therefore, the use of the hoisting method will soon lead to damage to the drive mechanism of the pan/tilt, or even burn the motor.
The total weight of the camera and its protective cover exceeds the weight of the PTZ. Especially for PTZs that are used outdoors, the weight of the protective cover is often too large, and there is often the problem that the PTZ will not move (especially the vertical direction). The outdoor pan/tilt head is faulty or even damaged due to poor ambient temperature, low temperature, waterproof, and frost protection measures.
6. When the distance is too far, the operation keyboard cannot remotely control the camera (including the lens) and the pan/tilt through the decoder
Solution: This is mainly because when the distance is too far, the control signal is attenuated too much and the control signal received by the decoder is too weak. At this time, a relay box should be installed at a certain distance to amplify the shaping control signal.
7 monitor image contrast is too small, the image is light
Solution: If this phenomenon is not the problem of controlling the host computer and the monitor itself, it is the transmission distance is too far or the video transmission line attenuation is too large. In this case, the line amplification and compensation device should be added.
8. The image clarity is not high, the details are lost, serious color signal loss or color saturation is too small
Solution: This is because the loss of the high-frequency end of the image signal is so large that the signal above 3 MHz is basically lost. In this case, either the transmission distance is too long and there is no amplification compensation device in the middle; or the distribution capacitance of the video transmission cable is too large; or the equivalent capacitance is concentrated in the transmission link between the core wire and the shielded wire. Caused.
9. Hue distortion
Solution: This is a fault phenomenon that can easily occur in long-distance video baseband transmission. The main reason is caused by the large phase shift of the high frequency band caused by the transmission line. In this case, a phase compensator should be added.
10. Operation keyboard malfunction
Solution: This phenomenon can basically be determined as the "deadlock" of the keyboard when checking the connection. The explanation of the operation of the keyboard, there are generally methods to solve the "crash", such as "whole machine reset" and other methods, this method can be used to solve. If it cannot be solved, it may be that the keyboard itself is damaged.
11. The host does not clean the image
Solution: The symptom of this kind of fault phenomenon is the interference of other pictures, or the interference of the line synchronization signal of other pictures on the screen after the selection. This is due to the poor quality of the matrix switcher of the host and the lack of isolation between images. If a radio frequency transmission system is used, it may also be caused by the system's cross-talk modulation and excessive modulation.
A large-scale television monitoring system that operates in conjunction with burglar alarms is a high-tech and complex system. Although various kinds of failure phenomena may occur, as long as the quality of selected equipment and equipment is properly shut down and construction is strictly conducted in accordance with standards and specifications, generally no major problems will arise. Even if there is a problem, as long as the analysis and thinking is calm, “doing the right thing†does not blindly make a big dismantling, it will solve the problem faster.
12. Bad communication failure
Solution: The performance of a controlled pan/tilt or motorized lens can sometimes be normal, sometimes it cannot be (or delayed), or it can't be stopped after the action. This is due to a problem with the communication line. Check the RS-485 communication terminal matching resistor (120|?) on the decoder when confirming the wiring is correct and the circuit is correct. Or disconnect the host interface and the far-end matching resistor, use a multimeter to measure the DC resistance RD of the terminal pin of the single communication chip and the DC resistance R2 of the communication port of the entire system, and compare it with the theoretical calculation (R2=R0/n, where n For the number of decoders connected in the entire system), if the difference is too large, it can be determined that there is a problem with the communication chip, and the problematic chip is found by the point-by-point elimination method. If the communication line has many branches, you can disconnect each branch to determine the approximate range of communication failures.
1. Incorrect equipment caused by power failure
Solution: There are several possibilities for incorrect power supply: incorrect power supply line or power supply voltage, insufficient power (or insufficient line diameter of a certain power supply line, excessive voltage drop, etc.), short circuit in the transmission line of the power supply system, and open circuit , instant overpressure and so on. In particular, the device may be damaged due to power supply errors or instantaneous overvoltage.
2. Line problem
Because some lines, especially those connected to the equipment, are not handled well, causing circuit breakers, short circuits, poor insulation between the lines, miswiring, etc. cause damage to the equipment (or components), degradation of performance, or failure of the equipment itself, but The phenomenon is reflected in the equipment or components. In particular, the quality of some connectors is poor, and the connection process is not good. This is a common cause of problems.
Solution: In this case, the analysis should be conducted calmly based on the fault phenomenon to determine which of the faults occurred on several lines due to the connection of which lines. This will reduce the scope of the problem. For example, a camera with three variable lens image signal is normal, but the lens can not control, you do not have to check the video output line, but just check the lens control line on the line. In addition, connectors, especially BNC type connectors, are very high in the welding process and the connection and installation process requirements of video cables. If they are not handled properly, even if there are no problems in the commissioning and commissioning stages, problems occur after a period of operation. It is particularly worth pointing out that cameras with pan-tilt heads have a long time due to all-round movements, resulting in disconnection and breakage of connections that are common. Therefore, special attention should be paid to the connection of equipment and various lines in this case to meet the requirements of long-term operation.
3. The quality of equipment or components itself
In general, there should be no quality problems with carefully selected commercialized equipment or components.
Workaround: Even if problems occur, they often occur after the system has been delivered and run for a long time. In addition to the quality of the product mentioned above, the most common problem is due to improper adjustment of the equipment. For example, the adjustment of the intercept after the camera is a very precise and precise job. Without careful adjustment, problems such as poor focusing or defocusing in various operations of the three-variable lenses may occur. In addition, whether the positions of some switches and adjustment knobs of the camera are correct, whether they meet the technical requirements of the system, the correctness of the encoder coding switch or other adjustable position settings directly affect the normal use of the device itself or affect the normal performance of the entire system.
4. Problems caused by incorrect connection between equipment (or parts) and equipment (or parts)
Solution: The impedance does not match. If the video is connected to a monitor with a high impedance, the image will be very bright, the characters may jitter, or sometimes there may be characters. The communication interface or communication method is incorrect. This situation often occurs between the control host and a device such as a decoder or control keyboard that has a communication control relationship. This is mostly due to the fact that the selected control host and decoder or control keyboard are not products of one manufacturer. In general, different manufacturers use different communication methods or transmission control codes. Therefore, the same manufacturer's products should be used for the host, the decoder, and the control keyboard.
Drive capacity is insufficient or exceeds the prescribed number of device connections. For example, the number of main control keyboards and sub-control keys corresponding to the control host is regulated. Exceeding the prescribed amount will cause the system to work abnormally. Decoder pan/tilt working power power is lower than the actual pan-tilt, it can not drive the PTZ.
5. The failure of the head
A pan/tilt is incapable of operation or cannot rotate at a short time after use. It is a common troubleshooting method for PTZ: In addition to the product quality factors, the appearance of this kind of situation is mainly caused by the following reasons; only the camera is allowed to be The head mounted (that is, the camera sitting on the upper part of the turntable) uses a hoisting method (ie, the camera is mounted under the turntable). In this case, the hoisting method leads to an increase in the operational load of the pan/tilt. Therefore, the use of the hoisting method will soon lead to damage to the drive mechanism of the pan/tilt, or even burn the motor.
The total weight of the camera and its protective cover exceeds the weight of the PTZ. Especially for PTZs that are used outdoors, the weight of the protective cover is often too large, and there is often the problem that the PTZ will not move (especially the vertical direction). The outdoor pan/tilt head is faulty or even damaged due to poor ambient temperature, low temperature, waterproof, and frost protection measures.
6. When the distance is too far, the operation keyboard cannot remotely control the camera (including the lens) and the pan/tilt through the decoder
Solution: This is mainly because when the distance is too far, the control signal is attenuated too much and the control signal received by the decoder is too weak. At this time, a relay box should be installed at a certain distance to amplify the shaping control signal.
7 monitor image contrast is too small, the image is light
Solution: If this phenomenon is not the problem of controlling the host computer and the monitor itself, it is the transmission distance is too far or the video transmission line attenuation is too large. In this case, the line amplification and compensation device should be added.
8. The image clarity is not high, the details are lost, serious color signal loss or color saturation is too small
Solution: This is because the loss of the high-frequency end of the image signal is so large that the signal above 3 MHz is basically lost. In this case, either the transmission distance is too long and there is no amplification compensation device in the middle; or the distribution capacitance of the video transmission cable is too large; or the equivalent capacitance is concentrated in the transmission link between the core wire and the shielded wire. Caused.
9. Hue distortion
Solution: This is a fault phenomenon that can easily occur in long-distance video baseband transmission. The main reason is caused by the large phase shift of the high frequency band caused by the transmission line. In this case, a phase compensator should be added.
10. Operation keyboard malfunction
Solution: This phenomenon can basically be determined as the "deadlock" of the keyboard when checking the connection. The explanation of the operation of the keyboard, there are generally methods to solve the "crash", such as "whole machine reset" and other methods, this method can be used to solve. If it cannot be solved, it may be that the keyboard itself is damaged.
11. The host does not clean the image
Solution: The symptom of this kind of fault phenomenon is the interference of other pictures, or the interference of the line synchronization signal of other pictures on the screen after the selection. This is due to the poor quality of the matrix switcher of the host and the lack of isolation between images. If a radio frequency transmission system is used, it may also be caused by the system's cross-talk modulation and excessive modulation.
A large-scale television monitoring system that operates in conjunction with burglar alarms is a high-tech and complex system. Although various kinds of failure phenomena may occur, as long as the quality of selected equipment and equipment is properly shut down and construction is strictly conducted in accordance with standards and specifications, generally no major problems will arise. Even if there is a problem, as long as the analysis and thinking is calm, “doing the right thing†does not blindly make a big dismantling, it will solve the problem faster.
12. Bad communication failure
Solution: The performance of a controlled pan/tilt or motorized lens can sometimes be normal, sometimes it cannot be (or delayed), or it can't be stopped after the action. This is due to a problem with the communication line. Check the RS-485 communication terminal matching resistor (120|?) on the decoder when confirming the wiring is correct and the circuit is correct. Or disconnect the host interface and the far-end matching resistor, use a multimeter to measure the DC resistance RD of the terminal pin of the single communication chip and the DC resistance R2 of the communication port of the entire system, and compare it with the theoretical calculation (R2=R0/n, where n For the number of decoders connected in the entire system), if the difference is too large, it can be determined that there is a problem with the communication chip, and the problematic chip is found by the point-by-point elimination method. If the communication line has many branches, you can disconnect each branch to determine the approximate range of communication failures.
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