What are the GPS clock system timing methods?

The GPS clock system has the following main methods:

1. Pulse synchronization signal (hard-to-time): The synchronization pulse of the clock device is output in empty contact, TTL level, 422 level (differential), 24V/110V/220V active, current loop mode.

2. Time message (soft-to-time): When the device is synchronized, the device reads the time of the serial output of the synchronous clock once per second through the serial port. The serial port information includes year, month, day, hour, minute, and second, and may also include other special content specified by the user, such as receiving GPS satellites, alarm signals, and the like.

3. IRIG-B: A serial time exchange code applied to a shooting range. A time information coding standard proposed by the "target range instrument group" subordinate to the American Shooting Range Command Committee is now widely used.

4. NTP protocol: The Network Time Protocol (NTP) is a protocol used to synchronize the time of a computer. It can make the computer synchronize its server or clock source (such as quartz clock, GPS, etc.), which can provide high Accuracy time correction (less than 1 millisecond between LAN and standard, tens of milliseconds over WAN). SNTP Protocol: SNTP is an abbreviation of Simple Network Time Protocol. It is an important engineering method for implementing time synchronization on the Internet. The SNTP protocol uses a client/server working method. The server receives the GPS signal or the built-in atomic clock as the system time reference. The client obtains accurate time information by regularly accessing the time service provided by the server and adjusts its own system clock to reach the network. The purpose of time synchronization. The client and server communicate using UDP protocol and the port is 123.

5, DCF77 signal (Deutsche, long wave signal, Frankfurt, 77.5kHZ): German calibration signal (referred to as DCF77): Operated by the Physikalisch-Technische Bundesanstalt (PTB), launched from the southeast of Frankfurt. The carrier frequency is 77.5 kHz, and the time information encoding uses pulse width modulation.

The GPS clock system described above is introduced.