A jumper is provided as a control input means for switching operation modes of a CardBus controller. The magnetic toner is of an average particle size 0. Microprocessors are arranged on the boards, and the boards are connected to each other in a serial communication, thereby reducing the number of wiring harnesses and thus configuring the printed circuit board assembly with high reliability. The method includes checking in each firewall whether there is a change of the VRRP state from primary to secondary or reciprocally. The additional blocks are either the older blocks or the newer blocks depending on the direction value.