HP 3000 Enterprise Virtual Array - Manual (Page 58)

Enclosure number feature
This section provides a description of the purpose, function, and operation of the EMU enclosure number
(En) feature.
En description
In a single rack configuration, the En is a decimal number in the range 00 through 14, which is
automatically assigned by the enclosure address bus.
NOTE:
Your storage system may use an enclosure address bus higher than 14 if your configuration includes an
optional expansion cabinet. The enclosure address bus connection determines the En. For a single rack,
the display is a decimal number in the range 01 through 14. For a multiple (two) rack configuration, the
display is decimal number in the range 01 through 24.
By default, the two-character alphanumeric display shows this number. Pressing the bottom push button
changes the display to En, the En display mode.
When the display is En, pressing and releasing the top push button displays the enclosure number.
A display of 00 indicates that the enclosure is not connected to the enclosure address bus. When this
condition exists, there is no EMU-to-EMU communication over the enclosure address bus.
A display of 01 through 14 indicates that the enclosure is connected to the enclosure address bus and
can exchange information with other enclosures on the enclosure address bus. The decimal number
indicates the physical position of the enclosure in relation to the bottom of the rack.
• 01 is the address of the enclosure connected to the lower connector in the first (lower) enclosure
ID expansion cable.
• 14 is the address of the enclosure closest to end of the bus, the upper connector in the last
(upper) ID expansion cable.
Unless there is an error condition, the display automatically returns to the enclosure number (01 through
14) one minute after a push button was last pressed.
Enclosure address bus
The enclosure address bus provides a means for managing and reporting environmental conditions within
the rack. It is composed of enclosure ID expansion cables that interconnect the drive enclosures and
controller enclosures. Two drive enclosures connect to each enclosure ID expansion cable.
The drive enclosure numbers are always assigned by the enclosure address bus. Connecting the EMU
CAB connector to an enclosure address bus enclosure ID expansion cable automatically establishes an
enclosure number of 01 through 14. Any drive enclosure not connected to the enclosure address bus
has the enclosure number 00.
NOTE:
The enclosure number is automatically assigned. You cannot manually assign an enclosure number.
The enclosures are numbered as shown in Figure 18 .
58 Enterprise Virtual Array hardware components