Based on beidou satellite network time protocol (NTP) of GPS synchronous clock design
1, equipment adopts redundant architecture design, high precision clock directly from the big dipper, each satellite atomic clocks, GPS system by analytical taming the local clock signal source, realize the satellite signal loss after the local clock accurate holding function, unique design of embedded hardware Linux operating system, a variety of flexible expand the clock signal output,
2, the equipment support/SNTP time protocol (NTP), certificate of MD5 encryption security protocols and encryption protocol, time precision is better than that of 2 milliseconds, at the same time support the TOD, 10 MHZ, 1 PPS, logging, USB port upgrade downloads and the dry contacts alarm function, so time unified monitoring software and easily realize the network time synchronization and effective monitoring,
3, by the 64 - bit high-performance CPU, high-speed FPGA and high stable oscillator (rubidium atomic clocks or OCXO), using Linux for multitasking real-time parallel processing and scheduling,
Big dipper system can receive at the same time, the GPS synchronization, and send the seconds information and meet/SNTP protocol (NTP) network time message, according to the priority automatically choose external time reference signal and the control guide into the source LOCKED (LOCKED). With input transmission delay compensation algorithm, using kalman digital filtering technology filter after external time reference signal jitter, to control and tame of rubidium atomic clocks or OCXO, 1 PPS signal can be obtained through the internal oscillator frequency division, so that the output 1 PPS signal synchronization in external time benchmark output 1 PPS signal value, long-term stability of the conquered by external benchmark seconds the effects of pulse signal jump, make the time of the output signal not only signal synchronized with external time benchmark and more stable,
When external lost time reference signal into punctual keep state (HOLD - OVER), when the external reference signal recovery time, punctual automatic end keep state and traction tracks to the locked position, thus continuous output and UTC synchronized time information,
