A pressure medium-actuated control device (1.1, 1.2, 1.3, 1.4) of an automated step-by-step variable speed transmission with an actuatable clutch control valve (3, 3.1 3.2) for controlling a control clutch cylinder (2, 2.1, 2.2) of an actively closable decoupler type clutch disposed in a flow of power between a drive motor and an input shaft of the step-by-step variable speed transmission,
- a self-retaining valve (5) disposed in a pressure supply of the clutch control valve (3, 3.1, 3.2) for rotational speed-dependent emergency actuation of the decoupler type clutch,
- an electrically selectable disconnection actuator (8) being constructed and operatively connected to the self-retaining valve (5) such that a valve piston (42), of the self-retaining valve (5), is movable into an idle position locking the pressure supply of the clutch control valve (3, 3.1, 3.2) in powered state of the disconnection actuator (8), and into an operating position determined by applied control pressures in the unpowered state of the disconnection actuator (8), the disconnection actuator (8) being a hydraulic solenoid switching valve (56) having a connection of a control pressure supply line (33) conveying reduction pressure (P_Red), having a connection of a switching pressure line (49) to a front-side pressure chamber (48) of the self-retaining valve (5), containing a valve spring (41), and having a connection of a depressurized line, by which the switching pressure line (49) is connected to the depressurized line, in the unpowered state of the disconnection actuator (8), and to the control pressure supply line (33) in the powered state of the disconnection actuator (8), the self-retaining valve (5) has a concentric pressure chamber (43) which, on a spring side, has a controllable connection of a supply line (44) conveying a supply pressure (P_V1), which concentrically has a connection to a supply pressure connection line (25) leading to a supply connection of the clutch control valve (3), and which on a side facing away from the spring has a controllable connection of a depressurized line, and with a further concentric pressure chamber (45), which has a connection of a control pressure line (46) conveying a control pressure (P_Nor) during normal operation and which on the spring side is restricted by a larger active surface of an adjacent piston collar (47) than on the side facing away from the spring, and the pressure chamber (48) containing the valve spring (41), which has a connection of the switching pressure line (49) leading to the switch-off actuator (8), and a front-side pressure chamber (50) facing away from the valve spring (41), which has a connection of a control pressure line (52) conveying a rotational speed-dependent control pressure (P_D) which is closable via a control edge of a piston collar (51) adjacent on the spring side.