Equipment and component failures of common faults in monitoring systems

Common fault phenomena of the monitoring system and their solutions may occur when a monitoring system enters the commissioning stage, trial operation stage and after it is delivered for use. These fault phenomena either cannot operate normally or the system cannot meet the technical indicators required by the design; Or the overall performance and quality are not ideal, and there are some so-called "soft problems". These problems are unavoidable for a monitoring project, especially for a complex and large-scale monitoring project. It is the obligation and responsibility of engineers and technicians to solve these problems when they occur.

The faults and solutions caused or reflected by the equipment and components should be debugged and powered on as required before the equipment (or components) are installed. But nonetheless, it is common for equipment (or components) to fail due to some reason during installation.

A. Equipment failure caused by incorrect power supply. There are roughly the following possibilities for incorrect power supply: incorrect power supply line or power supply voltage, insufficient power (or the diameter of a certain power supply line is not enough, the voltage drop is too large, etc.), the transmission line of the power supply system is short-circuited, open-circuited, or instantaneously crossed. pressure and so on. In particular, equipment damage due to power supply errors or transient overvoltages often occurs.

B. Due to the poor handling of some lines, especially the lines connected to the equipment, open circuit, short circuit, poor insulation between lines, misconnection, etc. lead to damage to the equipment (or components), performance degradation or the equipment itself is not damaged. , but the reflected phenomenon is on the device or component. The above problem occurs because there are many connections for some devices (such as cameras with three variable lenses and PTZs), which are often not handled properly. In particular, the quality of some connectors is poor, and the connection process is not good, which is a common cause of problems. In this case, it should be calmly analyzed according to the fault phenomenon, and it is judged that the fault phenomenon occurs because of which lines are connected with problems on several lines. This narrows down the scope of the problem. For example, if the image signal of a camera with three variable lenses is normal, but the lens cannot be controlled, there is no need to check the video output line, but just check the lens control line. In addition, in terms of connectors, especially BNC-type connectors, the requirements for welding process and video cable connection and installation process are very high. It is particularly worth pointing out that due to the omnidirectional motion of the camera with the gimbal, it is common for the connection to fall off and break for a long time. 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.

C. Quality problems of the equipment or components themselves. In general, carefully selected commercialized equipment or components should not have quality problems. When problems do occur, they tend to occur after the system has been delivered and in operation for a considerable period of time. In addition to the quality problems of the products mentioned above, the most common problems are caused by improper adjustment of equipment. For example, the adjustment of the back intercept of the camera is a very delicate and precise work. If it is not adjusted carefully, there will be problems such as poor focusing or defocusing during various operations of the three-variable lens. In addition, whether the positions of some switches and adjustment knobs on the camera are correct, whether they meet the technical requirements of the system, and whether the settings of the decoder code switch or other adjustable parts are correct or not will directly affect the normal use of the device itself or the normal performance of the entire system.

D. Problems caused by incorrect connection between equipment (or components) and equipment (or components). Problems in this regard generally occur in the following aspects:

a. Impedance mismatch. If the video is connected to a high-impedance monitor, the image will be very bright, the characters will be jittery, or the characters will sometimes disappear.

b. The communication interface or communication method is incorrect. This situation often occurs between the control host and the decoder or control keyboard and other devices that have a communication control relationship. This is mostly caused by the selected control host and decoder or control keyboard, etc., which are not products of the same manufacturer. Generally speaking, different manufacturers use different communication methods or transmit control codes. Therefore, products from the same manufacturer should be selected for the host, decoder, and control keyboard.

c. The drive capacity is insufficient or exceeds the specified number of device connections. For example, the number of main control keyboards and sub-control keys corresponding to the control host is specified. Exceeding the specified number will cause the system to work abnormally. The working power of the decoder gimbal is lower than the actual gimbal, so it cannot drive the gimbal.