Abstract This paper describes a numerical model for a passive microsystem to detect and save acceleration shocks. For the first time a system is presented, where more than one or two acceleration events can be detected and saved and where the latching position is not influenced by the seismic mass position before the acceleration event. Therefor the latching positon indicates the maximal external acceleration amplitude acted on the microsystem. A numerical model is used for prediction of the dynamic system behavior. Utilizing the model a parameter study was performed to determine optimal parameters for clear correlation between ratcheting position and its acceleration threshold. A mass of the ratcheting parts in the same range as the seismic mass enable a clear result in a range of up to 500 g and five latching positions.