A mass storage cabinet having passive device position sensing and including shelves
for racking device enclosures. A cabinet bus is linked to the shelves and adapted
to provide a unique shelf identifier signal to each of the shelves. The cabinet
includes a device providing a cabinet identifier to the shelves. The cabinet bus
includes junction boxes having first and second sets of sensing wires and a side
connectors linked to the shelves for providing the shelf identifier signal from
the first and second sets of sensing wires. To provide a different signal at each
junction box, the sensing wires in the first set are moved one position and the
sensing wires in the second set are moved one position prior to the connection
to an adjacent junction box. An additional sensing wire is linked to the side connectors
and grounded and ungrounded at each side connector to alter the signal.
