An antenna assembly has an antenna set, a rotation assembly and a control circuit for driving the rotation assembly to rotate to adjust receiving angel of the antenna set. The first friction surface arrangement and the second friction surface arrangement are brought into frictional engagement by the pressing arrangement. The seal assembly enables a robust, easily assembled three-component sub-assembly of the seal seat, grommet and pump component that can be handled as a single unit, and which easily installs onto, seals with, and becomes rotationally locked to a shaft. By using the fast operating grounding switch and controlling this on the basis of the detectors placed inside the CSS, an active arc fault protection is achieved. The medical line manager is configured to receive and removably retain at least one medical line therein. The stack processor is operative in response to as many as 64 possible instructions based upon a 16 bit word.