A configurable switched capacitor block includes a switched-capacitor sampling circuit, a fully differential amplifier, an SC feedback circuit, and a comparator. Access to files on the storage devices is arbitrated by the cluster filesystem using tokens. The camshaft is fixed to a camshaft wheel having a predetermined pattern of camshaft wheel marks. The fluid barrier can have various embodiments that prevent andor allow predetermined amounts of fluid into the anti-creep zone. When the instrument has been properly inserted in the through-opening, the sealing element seals off the two regions from each other. The chamber further includes an air outlet spaced from the chamber opening.