The mechanical features of the switching elements guarantee the reliable switching of the daisy chain without contact losses. The switching elements are located in contact positions a21-a22, b4-b5, b6-b7, b8-b9 and b10-b11. The switching elements close the daisy chain when no daughter card is inserted. Therefore, active components or jumpers are not necessary on VME64x backplanes. The switching solution integrates five pairs of switching contacts that short the VME interrupt lines when the daughter card is removed, preserving the integrity of the entire system. The har-bus 64S is an addition to the vendor’s five-row 160-way connector range har-bus 64 and is fully compatible with the har-bus 64 daughter card connectors.