With the rapid development of high-definition digital transmission system, Industrial Ethernet switches play an increasingly important role in the intelligent traffic monitoring system.
After the intelligent traffic enters the data excavation, the data application era accelerates. The digital network data such as GPS positioning, bus dispatching, station monitoring and so on plays an increasingly important role in real life. The performance is that many cities now have 3G monitoring , GPS traffic control, ITS and other systems. Industrial Ethernet switches play an important role as an indispensable transmission device in intelligent transportation system.
According to a research report released by cutting-edge research institutes in the security industry, the market demand for industrial Ethernet switches in China has risen sharply since 2005. According to Inaccurate Statistics In 2008, China's industrial Ethernet switch market reached 540 million yuan and is expected to grow at a rate of 26.2% in the future (as shown in Figure 1, CAGR is 26.2% in 2008-2013).
Figure 1 Industrial Ethernet Switch Market Size
Industrial Ethernet switches in the rapid growth of the country, its power and rail transit is the focus of industrial Ethernet switch applications, in metallurgy, petrochemicals, industrial control, building automation, prison monitoring system in Industrial Ethernet Network switches are also widely used. Industrial Ethernet switches different from the general nature of commercial Ethernet switches from the "reliability", that is, the reliability of the device itself and the degree of network architecture reliability, embodied in the following aspects (Table 1)
Table 1 Industrial Ethernet Switches and Commercial Ethernet Switches Reliability Comparison
Industrial Ethernet switches
Commercial Ethernet switch
Reliability of the device itself
Site installation (to adapt to the more demanding and demanding environment)
Installed in a dedicated network chassis
MTBT 20 years ago, or even longer deadline
No corresponding standard (usually a few years to ten years)
Adaptable to -40 to 80 ℃ operating temperature, 5% to 90% non-condensing humidity and other complex environment, a strong anti-jamming performance
High environmental requirements, such as room temperature, humidity and vibration-free, click, etc., poor immunity
Network Architecture Reliability
A variety of redundant combinations, such as redundant power supply
No redundancy or only core redundancy
Star, double star, ring, double ring type
Star, bus, tree
2, intelligent traffic monitoring system for industrial Ethernet switch needs
As we all know, HD network camera resolution, the higher the resolution, the transmission of the code stream will increase, increasing the network bandwidth pressure. Therefore, the formation of network transmission system for HD network video surveillance system is crucial to the formation, if the transmission system can not meet the network video streaming transmission requirements, then the network monitoring will be impossible.
According to the features of the megapixel network camera, if the ONVIF network video standard is adopted, the burst peak traffic of each 1080P full HD network camera can reach 50Mbps and the burst peak traffic of a 720P HD network camera can reach 25Mbps. Therefore, each monitoring area aggregation switches and monitoring center of the core switching equipment should have strong data exchange capabilities and carry a burst of multi-user high-capacity peak access capabilities for rapid exchange of network video data to meet the fast response to data access requests.
In response to this situation, the major solutions currently in the industry are undertaken by the central core switch with a gigabit switch with high backplane bandwidth and packet transfer rate. Such a solution requires that the entire equipment room and front-end equipment have gigabit bandwidth, and the cost of laying, operating and maintaining is high. To this end, I Division special research and development of multi-service with cache industrial-grade switch products. The 100 Mbps switch is upgraded and smoothed by adding a buffer to smooth the bandwidth. This solution perfectly solves the buffering of traffic bursts and the smoothing of the rate of network services without increasing the bandwidth cost. (Figure 2)
Figure 2 Industrial Ethernet Switch Functional Block Diagram
At the same time, multi-service industrial switchboard with cache can support up to 3 low-speed data interfaces, each port can be individually configured RS232, RS485 or switch business, through a core optical fiber traffic light control, traffic monitoring, LED large screen, alarm And other data back to the central computer room, not only streamline the original low-speed data transmission equipment, reducing engineering costs, but also for the latter part of the management and maintenance to reduce the hidden dangers.
3, application example analysis
3.1 complex crossroads monitoring program
According to the planning requirements of a traffic command center, our company designed and developed a set of video monitoring and transmission system specially applied to crossroads at a traffic intersection, realizing all-round real-time monitoring of the traffic crossroads, Equipment costs greatly reduce the cost of the cost, which greatly improves traffic jams car and pedestrian flow complex monitoring efficiency, effectively improve the remote staff and dispatchers through real-time image information for comprehensive monitoring and analysis capabilities. Specific analysis as shown in Figure 3:
According to the field analysis, we learned that four traffic junctions of a crossroads intersection are respectively equipped with different numbers of IP cameras. According to the number of IP cameras, we can pass different signals through optical fiber in a ring with a Fast Ethernet switch Link together, pay the final four intersection Industrial Ethernet switches converged signals are all merged into our newly developed hybrid Industrial Ethernet switches (the device is a redundant dual redundant power supply industrial aggregation switches , It can be the largest four 10 / 100M Ethernet electrical port and four 100M Ethernet optical port through two 1000M Ethernet optical port to achieve convergence.), Then by the hybrid Industrial Ethernet switches through the optical fiber will be different Business signals back to the traffic police command center of the general election gigabit switches, and finally connected to the user terminal to achieve the effective transport of information at the crossroads of the entire transmission of information fast, high speed, timely and effective.
Figure 3 complex intersection monitoring program
3.2 intelligent traffic monitoring program
In order to solve the problems of intelligent traffic monitoring that multiple IP cameras work at the same time to generate large code streams and different service transmission problems, we specially developed a series of industrial Ethernet switches with low-speed data for a certain intelligent traffic monitoring. This series is the perfect solution to the buffering of high-throughput burst network services, the smoothing of the rate of network services and the remote transmission of low-speed data interfaces with industry-leading performance advantages. With a compact size, wide operating temperature, redundant power connections, IP40 protection, LED indicators, this series of products is the best choice for industrial-specific applications and is the most reliable solution for Industrial Ethernet connections. POE unmanaged industrial switches support IEEE802.3at standard 25.5W power output, power and IP cameras can be powered by network-based POE technology for high-definition network cameras, wireless APs and IP telephones without power and power cables. Specific as shown in Figure 4:
Figure 4 low-speed data Industrial Ethernet switches
3.3 Key Technologies and Innovation
The above key technical solutions and innovations are as follows:
Traditional system due to inconsistent before and after the end of the device caused by a larger code rate problem, and solve the problem of caching can only be upgraded to Gigabit through the megabyte rate, bandwidth smoothing function can now effectively solve the large-flow burst network services Buffer, the rate of the network business is smooth, and can realize the long-range and effective transmission through the low-speed data. This will not only greatly reduce the construction / wiring costs, more convenient for managers to work.
In the past, the transmission of multi-service information mostly used different equipment for transmission. Now a low-speed data Ethernet switch can effectively and rapidly transfer different services at the same time, instantly reducing the cost several times and reducing the number of managers The workload.
A variety of redundant design, it is able to cope with a variety of harsh conditions of equipment under the work environment, to a certain extent, can increase the service life of equipment, reduce system replacement costs.
To sum up, the multi-service industrial switchboard with cache can perfectly solve the problem of multi-service transmission and cache without increasing the bandwidth and can be widely applied to various fields of digital video surveillance of HD network, such as intelligent traffic monitoring system.