  This work focuses on the generation of a composite clock for time scales and
shows the advantages of a more recent digital approach with respect to a
traditional analog one. A digital approach directly processes the information
contained into the clock sinusoids, instead of the sinusoids themselves and
leads to significant advantages in terms of reliability, performance,
complexity, flexibility, size, power consumption and cost. A practical example
based on a new digital instrument is provided to show how it is possible to
combine state-of-the-art clocks from the Oscillator Imp platform at FEMTO-ST
and FEMTO Engineering (Besan\c{c}on, France).
