A modular hemostatic valve includes a splittable valve body. By providing for at least one degree of rotational freedom between the rod and an anchoring element that is firmly connected to the bone or vertebra, the transfer of torque onto the anchoring element and can be prevented as well as loosening or even separation of the bone anchoring element from the bone or vertebra. The heat sink surface has a pattern of channels therein which define multiple heat sink substructures. Liquids flow from the bottom of the expansion chamber through a generally U-shaped line having a sediment trap therein. The system power number overflow problem is also detected with a counter if the incoming number is smaller then the number previously stored. The format does not require a third word when a frame is in an input queue.