16 Peripheral Bay Backplane: Description; Warnings And Cautions; Peripheral Bay Backplane - Intel AC450NX Product Manual

16 Peripheral Bay Backplane: Description

This chapter describes the peripheral bay backplane and lists its SCSI ID.

Warnings and Cautions

Only a qualified service technician is authorized to remove the server covers and to access any
of the components inside the server. Before removing the covers, see "Safety Guidelines" on
page 115.

Peripheral Bay Backplane

The WideUltra disk backplane supports hot-swapping of SCA-type SCSI drives, manages the
enclosure (chassis), and monitors server functions conforming to the SCSI-Accessed
Fault-Tolerant Enclosures (SAF-TE) specification. The disk backplane provides:
•
an independent SCSI channel
•
two SCA-2 connectors for SCA-type SCSI hard disk drives
•
active terminators that terminate the backplane end of the SCSI bus (SCSI-3 compliant)
•
power control for each drive that automatically powers down a slot when a drive failure is
detected and reported or a drive is removed (when a new drive is inserted, the power control
waits a few moments and then applies power to the new drive)
•
three light-emitting diodes (LEDs) for each drive
 power LEDs indicate the drives are receiving power
 activity LEDs indicate the drives are being accessed
 drive fault LEDs indicate the failure status of each drive (during server initialization, they
flash for one second)
•
2
intrachassis I C bus
•
2
I C bus temperature sensor for each microcontroller
•
2
interchassis I C bus support, per SAF-TE specification
•
serial EEPROM for nonvolatile information storage
The SCA-2 connectors on the disk backplane provide control signals and power for up to two
wide/fast 3.5-inch SCA-type SCSI hard disk drives. The backplane receives control signals from a
Symbios 53C896 host adapter on the PHP I/O baseboard.
The fault indicator LEDs on the front panel indicate failure status for each drive in the hot-docking
bays. These indicators get their signals through a cable connected to the front panel connector on
the disk backplane.
The temperature sensor on the disk backplane provides temperature information to other devices in
the server through enclosure service messages.
The disk backplane power control provides powering down of a drive when a failure is detected
and reported to the SCSI bus through enclosure service messages. When a new drive is inserted in
an SCA connector, the power control waits a short time for the drive to become fully seated and
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