Setting device for a pressure regulator includes a tubular casing developing according to a longitudinal axis (X) and in which there are a movable body, a sliding setting plate and a spring interposed between them; an adjusting unit suited to adjust the position of the setting plate and having a first rotating shaft connected to the setting plate through a screw mechanism which converts opposite rotations of the first shaft into corresponding opposite movements of the setting plate along the longitudinal axis (X), and an electric motor powered by a control device and provided with a second shaft constrained to the first shaft. The control device includes two different input lines to receive corresponding electric signals and an output line to supply power to the electric motor and is configured to transmit an electric pulse emitted by any of the input lines to the output line with polarity depending on the input line which emitted the electric pulse.