Principal clock
Encyclopedia
In telecommunication
s, the principal clock of a set of redundant clock
s, is the clock that is selected for normal use. The principal clock may be selected because of a property, e.g. superior accuracy, that makes it a unique member of the set.
The term "principal clock" should not be confused with, or used as a synonym for, the term "primary frequency standard
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Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
s, the principal clock of a set of redundant clock
Clock
A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece...
s, is the clock that is selected for normal use. The principal clock may be selected because of a property, e.g. superior accuracy, that makes it a unique member of the set.
The term "principal clock" should not be confused with, or used as a synonym for, the term "primary frequency standard
Frequency standard
A frequency standard is a stable oscillator used for frequency calibration or reference. A frequency standard generates a fundamental frequency with a high degree of accuracy and precision. Harmonics of this fundamental frequency are used to provide reference points.Since time is the reciprocal of...
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