NTP clock source (GPS time source) Introduction and Analysis

NTP clock source (GPS time source) Introduction and Analysis of
Beijing Electronic Science and Technology Associate
NTP clock source (GPS time source) Introduction and Analysis of
Beijing quasi-Electronic Technology (ahjzsz.com)
With the rapid development of information technology and network technology, domestic colleges and universities, hospital in strict accordance with the provisions of relevant state departments, the configuration of the system complete time synchronization schools, for schools, for hospitals to provide a unified standard Beijing time information. The accuracy of meaning gps network time electronic clock hanging in the corridor of the hall, classrooms, a major office.

First, what electronic clock is the network?

Broadly speaking: electronic clock network is usually a composite clock system i.e. ntp network time servers and the display time information display units composition; narrow dimension substantially on said network clock electronic clocks are merely specific time information is displayed led clock. Literally electronic clock network is easy to see, the whole works is inseparable from the support of network conditions, network electronic clock having a relay function in practical applications. Master clock and slave clock can be tied directly or by way of the switch. Electronic clock NTP network port to connect to accept the master clock NTP port can be used to send cable; when the units are in general use dozens or even hundreds of table clock needs grant, then you just need to play to the network function electronic clock network and master clock are simultaneously connected to the switch core.

Two, gps time electronic clock source selection

gps electronic clock as the name suggests, this time electronic clock source is gps satellite signals specific to the application, we recommend using gps Compass and two kinds of satellite signals. While GPS does not charge any fee to end users, but at the same time positioning accuracy and timing accuracy is not make any guarantee, be taken in order to ensure their own interests selective availability policies such intangibles reduces the positioning accuracy and timing accuracy. In short gps risk, reliability can not be guaranteed.

China has independently developed the Beidou satellite navigation system, though started late, but rapid development. Beidou satellite GPS functionality and compared favorably, in theory, large Beidou satellite coverage, no communication blind spot, the system covers China and neighboring countries and regions. Also good timing system, can achieve stable single star award, gps using low-orbit satellite movement due to satellite switching will affect the timing accuracy. Beidou using geostationary satellites in geosynchronous orbit, to ensure that always receives the same satellite, ensure that the entire satellite switching time service applications need not occur, the timing to ensure stability and reliability.

In practical applications, network electronic clock which, although in some cases gps star result slightly better than the Big Dipper, but that is the United States, in order to reduce the risk, it is recommended to select Compass gps and dual-mode. Especially the core key sectors of the country, can be used as a single Beidou Beidou is the Chinese autonomous control systems, high safety factor.

Third, the network electronic clock classification

The present mainstream market electronic timepiece network generally can be divided into three types, one is the satellite time version of a timing when a CDMA version, then there interphone receiving frequency in the electronic network and WiFi wireless slave clocks can belong clocks category. Satellite network version of electronic timing clocks are usually with the use of composite clock, master clock Beidou satellite signal receiving gps or directly through an antenna, after passing through the core switch, to all the clocks in the real-time service under the LAN. Beidou GPS satellite signal has covered all of our territory, only need to install the antenna mushroom head waiting for the roof terrace or open area. This gps electronic clock, with its high stability, high reliability favored by the various enterprises and institutions, all network application range is currently the most widely used in electronic clocks, precision is the highest. LED and digital display clocks Analog clocks are two types to choose from, to meet the needs of different units of different occasions.

Electronic network timing clock

Compass, GPS network digital clocks

CDMA network version of electronic timing clock is receiving gps satellite signal acquisition time information obtained by the local telecom base stations, where long as the phone is capable of receiving signals, can be used. But the biggest drawback of such an electronic clock that is subject to the operator's policy, with the constantly upgrading technology, 4G technology is mature, there is news that 2G signal at any time may be substituted off. Once closed, CDMA version of the sub-timing clock will not work properly. Of course, even if you can use the local telecommunications base station signal will also be affected. But the CDMA sub-clock easy to use, very suitable for those places is inconvenient to set up an antenna unit, wiring, you only need power supply can be used normally. As we all know walkie-talkie frequency is 433M, once the network using the electronic clock frequency to standard time information is received, the signal is not good, easy to interference, multi-floor will certainly be more poor, more reliable recommendations or wired number.

WiFi clocks applicable to the WiFi network applications, wireless connectivity via WiFi network, access to standard time from the network, time, accuracy, must be close to the router to use only when the school day, usually need to connect the phone to set up WiFi hotspots and password user. This is typically used in homes. Hospitals, schools, subways, stadiums, airports and other high-precision time-stability requirements of the occasion into account all aspects of the preferred electronic clock wired network, installing an antenna that is used with composite clock. Master clock time acquired from the satellite, time clocks available on the master clock.

Fourth, the satellite network version of electronic timing clock Frequently Asked Questions

1, network synchronization clock requires additional expense when it granted?

A: The network time service function without having the card and other costs

2, when the network electronic clock go gps accurate?

A: When the satellite network clock timing plate, and the base real time clock synchronization information, the master clock is the standard astronomical time, one second is not bad.

3, if the satellites are lost, time will be accurate? Examination mask signal during the examination, for example,

A: quasi Beijing Electronic Science and Technology satellite network timing clock built-in high precision electronic chip, the cumulative error of about 0.1s every day, even if there is no signal within a week, the error is also a second, so the time displayed on slave clocks are accurate guaranteed.

4, the network electronic clock unplugged can display normal?

A: No matter what kind of electronic clocks are needed to power after the power supply will light.

5, if not the normal power supply, network electronic clock time affect it?

A: HR-XS200 network electronic time clock with battery backup, the screen turns off when the power failure time is not displayed properly, but the internal clock may run continuously for 1 year, that is to say as long as the power is not restored to their time needs to be recalibrated within one year.

Published 42 original articles · won praise 3 · views 10000 +

Guess you like

Origin blog.csdn.net/weixin_44990608/article/details/104971413