Abstract: The invention concerns a Safety tumbler for a member movable between a closed and an open position, said tumbler comprising a housing with at least one safety switch provided with an actuator and a locking element whose locking function can be activated via a drive triggerable by a control system via a triggering signal, and further comprising at least one signal transmitter which detects the position of the actuator, and at least one signal transmitter which detects the position of the drive and/or of the locking element for the purpose of producing corresponding two-channel signals, wherein an electric interface circuit is provided in the housing for connection to a data bus, the interface circuit converting the signals from the signal transmitters into the data protocol of the data bus (10) and generating the triggering signal from the data protocol of the data bus (10).