Method for Operating a Machine for Producing and/or Processing a Material Web

A method for operating a machine for producing and/or processing a material web, wherein a first drive unit is supplied by a converter with a current, a vibration propagating over the material web is captured via the first drive unit, the vibration is measured and transformed into a measurement signal that is examined for presence of a signature that differs from the basic waveform of the current, a web tear is thus identified if the signature propagating over the material web is missing during the evaluation of the electrical measurement signal, whereby no further sensors, in particular optical sensors, are required to capture the measurement signal, and the measurement also occurs independently of a torque, a speed or speed development of drive motors over time and, moreover, the detection of the web tear does not require a comparison measurement at the machine without a continuous material web.