At present, the rail transit in many cities, such as Beijing, Shanghai, Guangzhou, Shenzhen, Hangzhou, Nanjing, Tianjin, Chongqing, Wuhan, Xi’an, Chengdu and Shenyang, has been put into operation in China, and urban rail transit is in a period of vigorous development. As a very important system in urban rail transit, the integrated monitoring system also plays a key role. Hangzhou Fctel technology is aimed at the establishment of an important hardware equipment of integrated monitoring system backbone network, industrial Ethernet switch.
Application networking mode of industrial Ethernet switch
The integrated monitoring system has independent networking, and the industrial Ethernet is built independently by using the industrial Ethernet switch of the integrated monitoring system and the optical fiber provided by the communication system.
Introduction of industrial Ethernet switch Industrial Ethernet switch is a kind of Ethernet equipment that meets the needs of industrial field, is compatible with commercial Ethernet switch in technology, and has higher requirements in real-time communication, reliability, stability, security, environmental adaptability than commercial Ethernet switch.
The comparison between industrial switch and civil switch shows that the switching function is basically the same, but there are many differences. First of all, the strength and applicability of the product can meet the needs of the industrial site in terms of design and component selection; Secondly, it is more flexible in module expansion, with a variety of optical and electrical ports to choose from; In addition, the material selection, product strength, applicability, real-time, interoperability, reliability, anti-interference and intrinsic safety can meet the needs of industrial site. In addition, PCB board of industrial switch is generally treated with “three proofs”. We can determine the necessity of selecting Industrial Ethernet switch in industrial field from the following aspects. In the long run, the MTBF of general switches is 3-5 years, while that of industrial switches can be as high as 15-50 years; In addition, the industrial Ethernet switch itself has good ring network construction and self-healing advantages, and only occupies the optical fiber provided by the communication system, which greatly improves the flexibility, stability and future debugging convenience of the whole system.
At present, most cities in the construction of integrated monitoring system, it is recommended that the integrated monitoring system should use the optical fiber provided by the communication system, and use the industrial Ethernet switch hardware independent networking.
Concerns of industrial switches
Backplane bandwidth: I think the backplane bandwidth of the switch should be considered from two aspects: 1. The sum of the capacity of all ports x the number of ports should be less than the backplane bandwidth, which can realize full duplex non blocking switching, proving that the switch has the conditions to maximize the data switching performance. ② Full configured throughput (MPPs) = number of full configured Ge ports × 488mpps. The theoretical throughput of one Gigabit port is 1.488mpps when the packet length is 64 bytes. For example, a switch that can provide up to 64 Gigabit ports should have a full configuration throughput of 64 × 488mpps = 95.2mpps, which can ensure the non blocking packet switching when all ports work at the average line speed.
The switches with relatively large backplane and small throughput retain the ability of upgrading and expansion, but also have problems in software efficiency / ASIC circuit design; The overall performance of switches with relatively small backplane and large throughput is relatively high. The value of backplane bandwidth is relatively easy to determine and measure, but the throughput is generally a design value, and the test is very difficult and of little significance.
Thermal design: the density of electronic components used in modern electronic equipment is higher and higher, which will cause thermal coupling between components through conduction, radiation and convection. Therefore, thermal effect has become one of the most important factors affecting the failure rate of electronic components. For some circuits, reliability depends almost entirely on the thermal environment. The data show that the service life of components will be reduced by about 1 / 2 when the ambient temperature is increased by 10 ℃. This is the famous “10 ℃ rule”. We analyze the test report of 24 port network switch with fan heat dissipation, and test results of fanless switch and fanless switch at ambient temperature of 30 ℃, 40 ℃ and 50 ℃.
It can be seen that temperature has a great impact on industrial network products. If fan cooling is used, like civil switches, it can effectively reduce the internal temperature and extend the MTBF of the equipment, but the life of the fan itself is very limited (2-3 years). The switch equipment of Metro integrated monitoring system often runs all the year round as soon as it is turned on, and the operation environment is often worse. Dust and humidity will directly affect the operation of fans. In the design of active heat dissipation switch, the heat dissipation mainly depends on the fan. Once the fan fails and is not replaced in time, the service life of components will be reduced. The heat accumulation inside the switch will quickly lead to the performance degradation of the switch until the switch collapses. Therefore, the heat dissipation system design of industrial Ethernet switch is particularly important.
Application case of Hangzhou Fctel Technology Industrial Ethernet switch in metro system project:
In order to ensure the reliability of data transmission, a three-layer optical fiber ring network switch is used to form a ring network redundancy to realize link backup. Fctel technology industrial switch adopts gigabit optical fiber ring, combined with the unique ring network technology, self-healing < 20ms, and forwards the data to the central server through the three-layer routing function, which can ensure the testability and security of network transmission. The access layer uses crs7120 management layer 2 switch to forward the gate card data to the platform server and the central server.
Industrial grade design
*Comply with en50121-4 standard
*Support three-layer static routing, rip V1 / V2, OSPF, VRRP and other management functions
*Zero packet loss rate of Ethernet switch
*Fanless design, support – 40 ° C~+85 ° C
*Less than 20ms network redundancy recovery
*Enhanced network security
Product display of Fctel Technology Industrial Ethernet switch:
This series of products are industrial grade 8-port 100Base-T to 100base FX optical fiber conversion, mainly used for optical fiber network long-distance (20 / 40 / 60 / 80 / 120 km) transmission. This product provides 1-way 100m optical port; Eight 100M Ethernet ports share 100m bandwidth, and each bandwidth can be set through console port (Ethernet interface is switch port, which can support VLAN Division), that is, logical isolation; One console port. It has perfect alarm function, stable and reliable operation, low power consumption, high integration and small size.
The device is based on Ethernet switch chip +fpga scheme, and the remote OAM frame management function supports console network management /web network management / independent SNMP network management, and can also be connected with 1-optical 1 transceiver card with SNMP card with 2U plug-in card type and SNMP network management, and can be managed on SNMP software.
OK, the above content is about the application of industrial Ethernet switch in Metro and analysis of the scheme, hope to help you! Hangzhou Fctel has been focusing on the research and development, production and sales of optical fiber communication for 20 years. We mainly operate optical terminal, optical transceiver, industrial switch, protocol converter, etc. we provide customized product services for customers. Welcome to come to know and exchange. email：ethan@fctel.com.cn
