Hitachi AMS 2100 Hardware Manual page 270

6. Complete steps 1 - 3 in the Navigator 2 Add Trays window. The
expansion unit may be connected to the base unit or to another
expansion unit.
a. Complete the instructions in the following window when connecting
an expansion unit to a base unit.
b. Complete the instructions in the following window when connecting
an expansion unit to another expansion unit.
9–14
Upgrading the hardware
Hitachi AMS 2100/2300 Storage System Hardware Guide