Detailed explanation and analysis of GPS satellite timer (Beidou timing equipment)


Detailed explanation and analysis of GPS satellite timer (Beidou timing equipment)

Detailed explanation and analysis of GPS satellite timer (Beidou timing equipment)

Beijing Zhun electronic technology official micro enterprise — ahjzsz

Beijing Zhun electronic technology hr-901gb Beidou time service equipment

Product introduction

Beijing Zhun electronic technology hr-901gb Beidou time service equipment is a high-tech clock product with high precision, large capacity and high quality, which supports NTP and SNTP network time synchronization protocol.

Hr-901gb Beidou time service equipment adopts redundant architecture design. The high-precision clock directly comes from the atomic clock of each satellite in Beidou and GPS system. The local clock source is tamed through signal analysis to realize the function of accurate local clock maintenance after satellite signal loss. The unique embedded hardware design and efficient Linux operating system can flexibly expand a variety of clock signal output.

Hr-901gb Beidou time service equipment fully supports core NTP time synchronization protocol, MD5 security encryption protocol and certificate encryption protocol, with time accuracy better than 2 ms. At the same time, it supports Tod, 10MHz, 1PPS, log record, USB port upgrade download and dry contact alarm functions. With the unified time monitoring software of the whole network, the network time synchronization and effective monitoring can be easily realized.

Beijing Zhun electronic technology hr-901gb Beidou timing equipment can be widely used in medical, security, financial insurance, mobile communications, cloud computing, e-commerce, energy and power, petroleum and petrochemical, industrial automation, intelligent transportation, smart city, Internet of things and other fields.


product mix

Beijing Zhun electronic technology hr-901gb Beidou time service equipment innovatively integrates reference source seamless switching technology, high-precision time interval measurement tic technology and adaptive precision frequency measurement and control technology. Modular design is adopted, which is composed of Beidou receiver, GPS receiver, high-performance industrial motherboard, man-machine interface and monitoring management unit, local clock taming unit, output interface module and power module.

The core of Beijing Zhun electronic technology hr-901gb Beidou time service equipment is composed of 64 bit high-performance CPU, high-speed FPGA and high stability oscillator (rubidium atomic clock or OCXO). Linux is used for multi task real-time parallel processing and scheduling.

Beidou time service equipment can simultaneously receive second synchronization and time information sent by Beidou and GPS as well as network time message meeting NTP / SNTP protocol, and automatically select external time reference signal as synchronization source according to priority and control it to locked state. It has input transmission delay compensation algorithm and adopts Kalman digital filtering technology to filter out jitter of external time reference signal Rubidium atomic clock or OCXO is controlled and tamed. The internal oscillator is used to divide the frequency to obtain 1PPS signal. In this way, the output 1PPS signal is synchronized with the long-term stable value of the 1PPS signal output from the external time reference, which overcomes the influence of the jump of the second pulse signal of the external time reference, and makes the output time signal not only keep synchronous with the external time reference signal, but also more stable. When the external time reference signal is lost, it will enter the hold-over state. When the external time reference signal recovers, it will automatically end the time keeping status and traction tracking to the locking state. Thus, it can continuously output the time information synchronized with UTC.


Key features

1. Ultra high bandwidth NTP server

2. GPS / BeiDou dual reference source primary clock server

3. High performance industrial motherboard, embedded Linux operating system

4. Provide six independent 10 / 100 / 1000mbs network interface

5. Another NTP server can be connected to form a level 2 clock

6. Optional internal precision clock OCXO or rubidium atomic clock

7. Safe and efficient web user interface

8. Support SSH, SSL, SCP, SNMP, custommib, HTTPS, telnet and other protocols

9. Compatible with IPv6 and IPv4 protocols

10. The relative UTC time accuracy reaches nanosecond level

11. Support the output of sysplex time information required by IBM host

12. Support single satellite timing function in fixed position mode

13. VFD high definition vacuum fluorescent display

14. The reliability MTBF is 80000 hours

15. Support 4000 logs

16. Support remote wake-up and timer switch

17. Support MD5 encryption protocol

18. Support certificate encryption protocol

19. Support dry contact alarm function


Important functions

1. It can synchronize the clocks of tens of thousands of clients, servers and workstations

2. Improve the reliability and security of network system

3. Six NTP ports, convenient for network configuration and reconstruction

4. Improve the accuracy of network log file and the speed of network fault diagnosis and location

5. A variety of time sources can be referenced to obtain reliable and safe time

6. The 1U structure is easy to install and maintain

7. The intuitive network management interface is convenient for users to operate, control and manage

8. Support the binding function and realize the stand-alone backup quickly

9. Support heartbeat detection function, and realize the backup of the same IP of two devices


Technical parameters

Network protocol

NTP v1.v2.v3&v4(RFC1119&1305)


MD5 Authentication(RFC1321)


NTP Unicast,Broadcast,Multicast,Autokey TIME(RFC868) FTP(RFC959)DAYTIME(RFC867) DHCP (RFC2131)


SSH/SCP (Internet Draft)

SNMP V1, V2, MIB II (rfc1213) RSA asymmetric encryption

IPV4、IPV6、IPv4/IPv6 Hybrid


Server performance

1. GPS Beidou double reference source primary clock server, synchronization accuracy 1 μ s

2. Synchronous timing accuracy of user terminal: 0.5-2ms (typical value of LAN)

3. User capacity: it can support tens of thousands of clients

4. NTP requests: 14000 times / sec

5. Another NTP server can be connected to form a level 2 clock

6. Support more than 4000 logs


Time service GPS / BeiDou receiver

1. Frequency: GPS L1; BD2 B1

2. System mode: (settable): single Beidou / single GPS / hybrid positioning mode

3. Channel: 32 channels

4. First positioning time: cold start: < 35S; hot start < 1s, recapture < 1s

5. The timing accuracy is better than < 30ns (RMS)

6. Positioning accuracy: 3M (RMS)


front panel

1. VFD high brightness LCD displays satellite receiving status, time, number of satellites, longitude and latitude, height, IP of each network card and system working status;

2. Three color indicator light indicates whether the NTP service is started, whether the network connection is normal, whether the NTP request exceeds 8000 times / s, whether the satellite is locked, etc;


Rear panel

1. Antenna port: BNC, 1 channel, GPS L1; BD2 B1, output 5V DC

2. Network port: RJ-45, 6-way, 10 / 100 / 1000m adaptive Ethernet interface

3. Console: RJ-45, 1 channel, RS232 level, control interface

4. Tod: DB-9 female, 1 channel, RS232 level, time and position information

5. VGA: DB-9 female, 1 channel, display output

6. Alarm dry contact alarm: 3 pairs, power, GPS, port capacity alarm

7. 1PPS: BNC, 1 channel, accuracy 30ns (RMS)

8. USB: 1 way, backup, recovery and upgrade functions


Physical and environmental parameters

Size: 1U chassis 440 × 44.5 × 364mm

Weight: 3.5kg

Power supply: 220 V ± 20% 47Hz ~ 63Hz

Working temperature: – 10 ℃ – + 55 ℃ (host) – 40 ℃ – + 75 ℃ (antenna)

Storage temperature: – 45 ℃ – + 85 ℃ humidity: 95% non condensing

Power consumption: 20W