User`s guide

The second controller will occupy the SCSI ID #6 slot. The second controller will
not function correctly if there are attached devices in slot 6 of any storage shelf
for any port. Check that each port has no more than six SCSI–2 devices at ID
numbers 0 through 5. Enter the SHOW DEVICES command and look at the Port
column for each device to determine the number of devices configured on each
port.
Figure 4–11 is an example of a dual-redundant HSJ40 configuration with
controllers in SCSI ID slots 6 and 7.
Installation 4–25