clock normal mode

An operating condition of a clock in which the output signals are controlled by an external input reference. It is the expected mode. In normal mode, each clock in a chain has the same long-term average frequency, and the time error between the input and output of each clock is bounded. Only stratum 1 sources of timing require no input and therefore have a unique status of "normal" operation being equivalent to "freerun". Synonym [in ITU-T Recommendation G.810] locked mode.[T1.105.09-1996]