Seagate Medalist 2160N (ST52160N), Руководство по эксплуатации продукта

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3.0 Command set
The drives support a subset of the Group 0, Group 1 and Group 2
standard SCSI commands.
The commands are described in this section.
3.1 Command descriptor block
The initiator makes a request to the drive by sending a command
descriptor block (CDB) to the drive. Each CDB has the following common
characteristics:
•
Byte 0 always contains the operation code.
•
The three most significant bits (bits 7–5) of byte 1 contain the logical
unit number (LUN). This field is ignored if an Identify Message is sent.
•
The last byte is always zero.
3.2 Status byte
The drive terminates each command by sending the status byte (shown
below) to the initiator during the status phase before the command
complete message.
Bytes
Bits
7 6 5 4 3 2 1 0
0
Reserved
Status byte code
Rsvd
0 0 0
The status byte can be any of the following:
00
H
Good status. The drive has successfully completed a command.
02
H
Check condition status. The drive detected an error, an excep-
tion or an abnormal condition. In response, the initiator may issue
a Request Sense command to determine the nature of the condi-
tion.
08
H
Busy status. The drive is busy and is unable to accept a command
from an initiator. The initiator retries the command later. The drive
returns a busy status if 1) the initiator has not sent the disconnect
message and tries to queue a command or 2) the initiator rejects
the disconnect message and the queue is not empty.
Medalist Pro 2160N/2160WC Product Manual, Rev. A 35