Hardware Clock
Glossary
Hardware Clock 179
Introduction to GPS 179
Leap Indicator 180
NTP Daemon 180
Software Clock 180
Stratum 181
Timing Engine 181
Timing Source 181
UTC 181
Hardware Clock
The Hardware Clock manages the Input References:
n Gets the time from the highest priority reference that is available.
n Applies the UTC offset if the reference is GPS.
n Passes the time to the NTP daemon.
The NTP daemon includes a preferred server association for the Hardware Clock that can-
not be edited or removed.
Also see:
n TIMING - HW Clock (on page 42)
n NTP - Config
n Input References
n Timing Engine (on page 181)
Introduction to GPS
The Global Positioning System (GPS) is a worldwide radio-navigation system formed from a
constellation of at least 24 satellites that continuously orbit the earth. These GPS satellites
have several atomic clocks that are precisely synchronized to UTC from the U.S. Naval
Observatory (USNO). Coded signals are broadcast by each of the satellites with the exact
time and position of the satellite. All GPS receivers use an antenna to receive these signals.
Using a GPS receiver optimized for time (rather than position), it is possible to get extremely
precise synchronization with the satellites' atomic clocks.
997-01520-02 Rev. G2.......................................................................... Page 179
To Next Page
Loading...
