Abstract: The switching device includes a multiplexer (2) and a control device (8). The multiplexer has a first input (Y.sub.i) for receiving a first digital signal (S1), a second input (Y.sub.j) for receiving a second digital signal (S2), an output to emit a resultant digital signal (SR), and at least one control input. The control device send signals to the multiplexer's control inputs for switching the multiplexer from the first input to the second input and to introduce during the switching a characteristic sequence into the multiplexer output. This sequence may, in particular, be produced by a clock signal generator connected to a third input of the multiplexer.