Chapter 1. Product Description
EK–SMCPR–UG. A01
387404-001
1–19
The PVA has two status indicators:
•
The green power status LED in the power shut down switch. This LED is ON
whenever there at least four operational power supplies. When an error condition
occurs, the LED is OFF and the PVA reports the error to the EMU. The EMU also
monitors the power supplies for this condition
•
An audible alarm that beeps at a slow rate when the PVA detects removal of or
improper installation of the EMU. This ensures you are aware the EMU must be
replaced within 8 minutes to prevent a system shut down
The primary functions of the PVA include the following:
1) Ensures that there is a minimum of four operational power supplies in the
enclosure. If the PVA senses less than four power supplies, it notifies the EMU.
2) Allows the user to select the Compaq-supported device SCSI bus addresses for the
master and each expansion enclosure.
3) Monitors the EMU status and:
•
Notifies the user of removal of the EMU
•
Notifies the user when there is no master EMU
•
Notifies the user when there are multiple master EMUs
•
Provides the user a switch to disconnect dc power from the enclosure power
buses
•
Monitors the optional UPS for proper operation and reporting the UPS status (a
planned future capability)
1.3.3.1 Monitoring Power Supply Operation
For accurate, reliable transfer of data without data corruption or loss, the enclosure
requires a minimum of four operational power supplies to furnish both +5 and +12 Vdc
for operation of the following:
•
Storage Devices (SBBs)
•
Array controllers and cache memories
•
EMU
•
PVA