Abstract: The invention relates to a signalling device (12, 2; 42, 2A) for detecting an operating state (B) of a machine (1) or an appliance, and for transmitting an operating state signal (SS, B, B*) associated therewith to a receiver circuit (2, 42) which is a spatially separated part of the signalling device (12, 2; 42, 2A) and converts said signal (SS, B, B*) into an optical, acoustic and/or tactile signal and outputs the same. The operating state signal (SS) passes through an amplitude threshold value circuit (V) and part of the signal (B) exceeding the threshold value is supplied to a retriggerable time overtravel circuit (NS), during the time interval of which the final operating state signal (BE) is used to form the alarm signal.