Depending on the function of each part of the monitoring system, we can be the entire video surveillance system is divided into seven layers: presentation layer (such as monitor video wall, monitor), the control layer, audio and video processing layer, transport layer (audio and video cable, wired and wireless network), command execution control PTZ, lens, decoder, etc., used to protect and support acquisition layer, the execution layer devices bracket, shield, auxiliary equipment, including lenses, surveillance cameras, alarm sensors and other equipment acquisition layer. Of course, since the device is integrated increasingly high for some systems, some devices may be the identity of a plurality of layers at the same time present in the system. System as an important part of the monitoring system control functions should meet the following requirements: The monitoring system should be capable of manual or automatic operation, remote operation of the various functions of network camera, PTZ, lens, shield devices, and stability control effect reliable. The system should be able to manually switch or programmed to automatically switch the video input signal on a specified monitor fixed or sequential display switching image reconstruction time should be in the acceptable range is displayed. Matrix switching and digital video network virtual exchange / switch mode system should have a system of information storage function, should be maintained after the power supply is interrupted or shut down, all programming information and time information. The video monitoring system should have a linkage interface with other alarm systems, when the interlock signal is given to the video surveillance system, the other system, the system can be switched out in accordance with the predetermined working mode corresponding parts of the image to the specified on the monitor, and can start video recording apparatus linkage response time does not exceed 4s. Auxiliary lighting equipment should be coordinated with the corresponding linkage network camera image shows synchronized with the audio monitoring function of the monitoring system should have the ability to switch video and audio synchronization. The need for multi-stage or off-site control system should support the sub-control function, front-end equipment for real-time control terminal of the control response and image transmission should meet the safety management requirements. The monitoring system should ensure that the image of the scene, the sound information timely response, and meet regulatory requirements and monitor image information and voice information should have original integrity. Image recording functions of the monitoring system should meet the following requirements: playback of the recorded image data should meet the original integrity of video storage capacity and recording / playback bandwidth and retrieval capabilities to meet regulatory requirements. The system should be able to record the following image information, the the events live its whole process of image information; predetermined location alarm occurs when the image information; need to master other site dynamic image information. The system records the image information shall contain the picture number / address, the time of recording time and date. Alarm video should provide for important fixed area of ??the image recording before the alarm, according to the needs of the safety management system should be able to record live sound information. System monitoring or playback images should be clear, stable, and should meet the requirements of the safety management. The display on the screen should be the image number / address, time, date, etc.. The image display inside the elevator car should contain the information of the floor where the elevator car information and operating status. Selection and setup of audio and video signal transmission equipment in addition to the relevant provisions should be consistent with the current national standards, but also meet the following requirements: the transmission equipment should ensure that the transmission bandwidth, carrier-to-noise ratio and transmission delay to meet the requirements of the overall system indicators, the interface should be adapted to front-end and back-end equipment connection requirements. Transmission equipment should have its own security measures, and should have a tamper alarm function; encryption / decryption functions for the need for confidentiality of the transmitted signal, the device should be supported. Transmission equipment should be set up in the easy maintenance and protection of the area, and should be near the front / back-end video equipment. The selection of video switching control equipment should meet the following requirements: functional configuration of video switching control equipment should meet the redundancy requirements, and the lowest ones of the video input interface should allow a certain amount of redundancy. Video output interface, the lowest ones should be based on the demand for security management and display record configuration to determine the number of devices. Video switching control equipment shall be capable of manual or automatic operation the various lens, electric PTZ and other actions (such as steering, actions such as zoom, focus, aperture) for remote control. Video switching control apparatus should be capable of manual or automatic programming switching fixed or sequential display of all the input video signal in the specified monitor. Video switching control equipment should have the configuration information is stored boot or power is restored after a power interruption or shutdown, all programmed settings, network camera number, address, time can be memory in the system should be restored normal work . Video switching control equipment should have a linkage with other external systems interfaces. When linked with the alarm control equipment should be able to switch out of the image of the corresponding parts of the network camera, and display the records. When the system partakers control requirements, should be allocated according to the actual situation control terminal, such as control of the keyboard and video output interfaces, and in accordance with the need to determine the operating authority. Large integrated security systems should adopt the multimedia technology, so that text, dynamic alarm information, graphics, image, system operation is completed on the same computer. Selection and setting of the recording and playback network camera should be used in digital video recording equipment, and should have a tamper-resistant features, images (and sound) of storage capacity and playback quality should meet the requirements of standards and management use. In the same system, the specifications should be consistent with tape recorders and recording media, video equipment should have linkage interface. Need to record sound in the video at the same time, the recording equipment shall be able to simultaneously recorded images and sound can be synchronized playback. The image recording query retrieval equipment should be set in an easily accessible location. The display device should meet field conditions and requirements of the clarity of the display device should not be less than the clarity of the network camera, should be higher than 100TVL. The distance between the operator and the display device screen should be 4 to 6 times the screen diagonal display device's screen size should be 230mm to 635mm. Large screen display devices, such as the choice according to application requirements. The number of display apparatus is determined by the number and management requirements of the actual configuration of the network camera. Meet the management needs and ensure image quality, multi-screen display, multiple display devices simultaneously display should be installed in the equipment cabinet or TV display wall, in order to obtain better observe the effect. The settings of the display device should be located so that the screen without outside direct glare, when the the inevitable glare incident, should take corresponding dark measures. External knob / button should facilitate the operation, the device should be set to consider the design of the monitoring center unified, rational distribution, easy to operate, easy to maintain.
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