A value holding system includes a receiving unit that receives an instruction to add or remove a value relating to a payment, a judging unit that judges whether the instruction is identical to a previously received instruction, and a rejecting unit that rejects the instruction when the judging unit judges that the instruction is identical to the previous instruction. The interlocking mechanism includes a first and a second housing connected to each other, a first and a second sliding bar. Additionally, the ODTs for a first set of the buffer circuits can be enabled and disabled responsive to the ODT control signal and the ODT for at least one of a second set of the buffer circuits is disabled. A housing covering the conduit member collects andor contains the heavier matter that exits the through openings by the effect of centrifugal forces acting thereon.