ARRANGEMENT STRUCTURE OF SELECTION CONTROL LINE FOR LOW ORDER DEVICE

摘要

PURPOSE:To improve the degrees of freedom of low-oder devices by arranging control lines from a host device in such a manner that N units having >1 packaged low-order devices are inserted into a storage rack capable of accepting N units on preferential basis. CONSTITUTION:Control lines CHSL1-CHSL8 for selecting low-order devices are connected from the host device 12 to terminals X and Y provided to strorage rackes a1-a8 where units are inserted. A units is inserted into any storage rack and the host device 12 sends out a signal for selecting a low-order device to be used with top priority to the CHSL1; the priority decreases in increasing order of a number from the CHSL2. Consequently, units in storage racks are only replaced for altering the priority and the degrees of freedom of the low- order devices to the host device are improved greatly.