The non-linear disturbances of the divertor plasma caused by ELMs are observed by a number of divertor diagnostics. A dedicated averaging procedure is applied to the time traces of the signals to reveal the coherent behaviour in the ELM as well as the changes of ELM parameters during the ELM series. In typical ELMs saturation current Isat and Dalpha emission behave accordingly, but temporal evolutions are different in the outer and inner divertor legs. Te and Vfloat vary strongly during the early ELM phase where Isat rises. The power flux to the target and the plasma potential can be constructed from the averaged signals. They show a remarkably smooth behaviour so that even the radial electric field along the plate can be estimated. Double peaks appearing sometimes in the power flux are seen by the thermography aswell. Radial proles of Isat and I(U)-characteristics of single probe tips could be reconstructed using the ELM times for a sorting procedure.