In a valve drive train device, in particular for a valve drive of an internal combustion engine, with a switching unit comprising an actuator with a solenoid unit and with a control unit for monitoring switching operations of the switching unit provided for switching an axially displaceable cam element by means of a switch gate, the control unit for monitoring the switching unit is taking into account at least one characteristic value of a voltage integral over a voltage which is induced in a coil of the switching unit during the switching operation and is adjusting the value with respect to a characteristic limit value stored in the control unit.