into the basic operating mode if all parameters p i have been compared with the two decision threshold values s i i u2212 1 and s i i and none of the threshold values has been exceeded the positioning device is still in the basic operating mode i e even when one of the end positions of the windows is reached there is no adjustment of the position determined by the positioning device the parameters p i are then compared with the two decision threshold values s i i u2212 1 and s i i while the window is moving according to the illustrated process in order to provide for a permanent monitoring of the positioning device as the parameters p i have different physical units it is useful to transform the determined values of the parameters p i so that they can be compared with a uniform first or second decision threshold value however it is also possible that for each parameter p i an individual first and second decision threshold value exists for illustrative purpose however this embodiment is not shown in the flow diagram fig2 shows the flow diagram of a second embodiment of the method according to the invention initially like in the previous embodiment the positioning device is in the basic operating mode while the window is moving the parameters p i are compared with a threshold value s i if this threshold.