Principles of good and bad evaluation of urban video surveillance system

The basic evaluation principles of the urban video surveillance and alarm networking system are: whether the system can meet the actual use needs; whether the system can be managed and maintained; whether the system has expansion and upgrade capabilities, can provide conditions for intelligent function upgrades; whether the system is sustainable The ability to develop.

The technical evaluation of the system mainly includes 10 criteria:

1. Practicality. The system should consider factors such as local environmental conditions, monitoring objects, monitoring methods, maintenance and investment scale, etc., to meet the needs of the normal operation and social public safety management of the urban video surveillance and alarm network system.

2. Reliability and stability. The system should use mature technology and reliable equipment, with backup or redundancy measures for key equipment. The system software has the maintenance guarantee capability and strong fault tolerance and system recovery capability, to ensure that the system runs stably for as long as possible, and can be repaired or recovered as soon as the system fails.

3. Scalability. The distributed system and modular structure design should be adopted to meet the needs of system scale expansion, function expansion, and supporting software upgrade. Users can expand or cut the system at any time as needed, reflecting sufficient flexibility.

4. Advancement and inheritance. The construction of the urban video surveillance and alarm networking system cannot completely abandon the original analog-based system. The appropriate approach is to incorporate the original analog system as much as possible under the premise of planning a fully digital system. The ideal system is to make a seamless connection between the two to form a complete network video surveillance network.

5. Performance price ratio. The designer should reasonably set the system functions, correctly configure the system and select the equipment. Under the premise that the quality of key equipment is good, the overall price of the system is low, so that the system has a high cost performance. The camera selection at the front end of the system and the level of back-end software should be the focus of attention. If the number of front-end camera lines is less than 460 lines, the subsequent system will be of no avail, and it is impossible to ensure that the system has a clear image effect. In some applications, advanced features such as wide dynamic range are also required.

6. Convenience of system upgrade and maintenance. Due to the large scale of the system, the system software and core equipment should have automatic upgrade and maintenance functions; in addition, the city monitoring and alarm networking system is composed of multiple complex systems, including network, storage, operating system, platform software, various front-end equipment, etc. Therefore, it is required that each subsystem should have a work log record, including the system modules and core equipment.

7. System management functions and ease of operation. Considering the scale and complexity of the networked system, the management software platform should have a good system architecture, and the core management and business management of the system must be clearly separated to ensure that different application requirements are met. Due to the large number of various management servers, storage and forwarding servers in the system, the network management function of the system must be powerful, otherwise daily maintenance cannot be performed; the management and user interface provided by the system should be clear, concise, and friendly, and the control should be simple, Flexible, easy to learn and use, easy to manage and maintain.

8. The ability of the system to support secondary development. The number of cameras in a city ’s surveillance and alarm networking system is at least hundreds, and as many as tens of thousands, so the sustainable development of the platform must be considered. To achieve the goal of "creating value by video", the system must be qualified for secondary development. Only in this way can the platform's video resources be fully utilized.

9. The degree of security of the system. System security includes many aspects, mainly to prevent illegal users and devices from accessing, so in addition to different levels of authentication for different users (including administrators and users), it is also necessary to ensure that illegal devices cannot be accessed Go to the system. Networked monitoring systems are most vulnerable to hacker attacks, and effective security protection measures should be taken to prevent the system from illegal access, illegal attacks, and virus infections. In addition, unsafe factors such as lightning strikes, overload, power outages, electromagnetic interference, and man-made destruction are also needed to provide comprehensive and effective security measures.

10. Compatibility and standardization. Compatibility is the key to interconnecting devices from many different manufacturers and different protocols. The system should be able to effectively communicate and share data, as far as possible to achieve compatibility and interoperability between devices or systems. The higher the standardization of the system and the better the openness, the longer the life cycle of the system. Control protocols, transmission protocols, interface protocols, video and audio codecs, video and audio file formats, etc. should all comply with the relevant national standards or industry standards.

RS485 is one of the the most widely used serial interfaces in SCADA, remote control and telemetry applications.