HP Array Controller HSG V8.7 Software - Manual (Page 89)

Power Verification and Addressing
UltraSCSI RAID Enclosure 4–3
The PVA has two status indicators:
• A green power status LED that is part of the standby power
switch (C
ALLOUT 1). This LED is O N if there are at least four
operational power supplies. If an error condition occurs, the LED
turns O
FF .
Caution
Some array controllers bypass the standby power mode
functionality from the PVA standby power switch. Refer to
the array controller documentation for availability of this
feature.
Note
The standby power switch initiates the standby power mode
when the array controller is shut down. In this mode, ac
power is applied to the ac input box and the power supplies.
However, dc power is disconnected from the backplane.
• An audible alarm that sounds when the PVA detects removal of
the EMU. This alarm reminds the user to install an operational
EMU for restoring the subsystem to an operational status.
Functions
The primary functions of the PVA include the following:
• Monitors the enclosure EMU status and notifies the user when the
EMU is missing.
• Allows the user to select a Compaq-supported device SCSI bus
address (device ID) for each enclosure.
• Ensures at least four operational power supplies are in the
enclosure.
• Notifies the array controller if less than four operational power
supplies are functioning in the enclosure. The array controller
then removes power from the enclosure.