Length-adjustable filter cartridges are provided which in preferred embodiments include at least one length-adjustable end cap attached to an end of a generally cylindrical filter body. This includes providing an architecture having a set of test commands, the test commands including a set of one or more stimulation commands and a set of one or more result-testing commands, and defining a set of test verbs out of combinations of the test commands. The output terminal is mounted axially on the side opposite the sensor relative to the rolling bearing and forms an axial thrust for the inner ring of said rolling bearing.