Beidou time service system, GPS time service server

Time:2020-4-12

Beidou time service system, GPS time service server

Beidou time service system, GPS time service server

The clock system is called Beidou time service system, which limits the time information of all kinds of devices that need to synchronize the clock on the LAN to a small enough range based on the Beidou time deviation. Any time application system should have the growth and reduction of maintenance time. The internal time synchronization of the client must be synchronized with the active time, that is, the process that the system time must be accessed and kept synchronized, that is, the time signal of Beidou is converted into the reference time, because the internal client network of the system can play the role of maintenance time growth, maintenance time reference and external time Related, the synchronization process is limited to the internal stable system called time server. Therefore, we can call it passive synchronization or relative synchronization.

Beidou time service system is a system that can maintain the growth of time and the stability of time in the client network. The time transmission mode is from Beidou to time synchronization server. The transmission from Beidou time signal to network time client unit through computer network time server must go through two steps: first, the direct time transmission from Beidou to time server, and the network protocol transmission from time server to time client unit.

Direct time transfer technology mainly includes three types and six modes. The first type is coding mode, which mainly includes RS232C time coding of serial port and IRIG-B time series coding. Its common feature is to define time information such as time, minute, second and millisecond of year, month, day, year, etc. in binary, BCD or ascll coding mode to the level bits and bytes to be transferred, which are usually transferred asynchronously. The connection uses standard interface, which is relatively convenient and simple to use.

The second type is pulse type, mainly including 1PPS, lppm and lpph. They are periodic pulse timing signals. These pulse signals have fixed rising edge width and pulse width requirements, and their rising edge strictly keeps synchronization accuracy better than LUS with UTC. The third type is the frequency reference signal, which is often an associated modulation signal.

Beidou timing system products:

The GPS Beidou time service system developed by Jingzhun electronic technology in Anhui Province, based on the previous time server, greatly improves the performance indicators of the time service system, so as to reduce the failure rate and improve the work efficiency. Basically, it can be compared with the advanced GPS time service system abroad. The Beidou time service system receives the Beidou satellite and Beidou satellite time service signals, transmits the standard UTC time information through the network, and provides accurate, standard, safe, reliable and The front panel of the multi-functional NTP timing service displays the time, minute and second of month, day, year, number of search stars, system working status, power status and other information. It is a highly cost-effective network time synchronization server.

 
Beidou network time server

Beidou time service system is composed of Beidou antenna and Beidou clock server. It is connected by pre fabricated coaxial cable with BNC connector. It can be customized with two 10 / 100 / 1000mb / s adaptive Ethernet interfaces. Different network segments can be set for network time synchronization of field equipment. There are two kinds of time application of computer network: absolute time application and relative time application. The former takes time as an important parameter output and is further processed by time application system. The accuracy of time directly affects the scope and nature of application. Indicate the sequence of events, the accuracy of which does not affect the normal operation of the application system. The absolute time provided by the computer network time synchronization is mainly used in the following aspects:

(1) Public time resources;

Time resource is an important public resource. Many industries, such as telecom, bank, TV station, mapping, airport, station and so on, need very accurate time to provide services for them. Just as the video timing of TV stations, the audio timing of radio stations, and the time reporting of China Telecom can make it convenient for public users to use TV, radio and telephone to obtain standard time signals, the computer network timing can also enable users to use the network to obtain accurate time signals with higher accuracy. For example, the national time service center can provide network time service with accuracy better than 10ms.

(2) Distributed file processing;

The distributed file processing system based on computer network requires that all computers keep time synchronization in order to correctly process the application program. The network file system (NF) s is a time sensitive application program, which completely relies on each workstation to provide time labels for the files in the server. If the time errors between these workstations are large, the application can be executed The program will bring a series of illogical errors and deviations.

(3) Distributed database processing;

The consistency requirements of sequential data, historical data and real-time data in the distributed database determine that the system time between the distributed databases must be strictly synchronized, otherwise, any data and any operation in the database will lose significance.

(4) System security;

With the continuous expansion of computer network scale, more and more key businesses, password protection, encryption, electronic authentication and other security measures are increasingly important, many important security measures are related to time. For example, the electronic authentication service requires the user password of the encryption certificate to be strictly corresponding to the time mark. The certificate is only valid in a specific time window, so in this time window, the time of the client must be strictly synchronized with the time of the server.

(5) E-commerce

In e-commerce, many online transactions are time sensitive businesses, such as stock trading, bank transfer, e-payment, etc., all of which require the operating terminals in e-commerce system to keep time synchronization strictly. Especially for the settlement between banks, when the currency exchange rate changes greatly, a short time error may cause huge economic losses. In addition, there are many other applications, such as computer supported cooperative work, network billing, network management, e-mail, etc., which also require high-precision time synchronization.

Conclusion:

The key to the implementation of high precision time synchronization in computer networks lies in the selection of time synchronization algorithm, that is, how to solve the problem of transmission delay or delay modification. In the independent structure scheme, it is easier to determine the synchronization relationship, while the simple network management structure scheme is more suitable for large-scale or large-scale network time synchronization, such as cross regional securities trading system, telecommunication service system or In large-scale power plants, the integrated protection system can obtain more precise time resolution granularity by adopting simple network management structure. Computer network time service will provide more extensive time service than traditional telephone time service, broadcast time service and television time service.

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