Quantum LTO 4, Руководство пользователя

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SCSI Interface Overview Page 9
An Initiator that accommodates disconnect/reconnect can indicate this capability to
the tape drive during the Selection phase by asserting both its own Initiator SCSI ID
bit as well as the tape drive’s SCSI ID bit (allows the tape drive to know with which
Initiator to reconnect). The Initiator must also assert ATN before exiting the Selection
phase (prior to releasing SEL) and send an Identify message out of C0h to the tape
drive. This sequence causes the drive to enter the Message-Out phase when the
Selection phase completes.
The first message sent by the host after the Selection phase is an Identify message.
Under normal conditions, the first message sent by the tape drive after a
Reselection phase is also Identify. Under certain exceptional conditions, the host
may send the Abort message or the Bus Device Reset message instead of Identify
as the first message.
2.3.9 Message exception handling
Message exceptions are handled as described in the following tables. The numbers
in the tables identify the actions that the drive takes when an exception under the
identified conditions occurs. The actions are described following the tables.
IN Phase during which ATN is raised
Message
Selection Identify Command Data in Data out Status Negotiate
Abort (06h) 2 2 2 2 2 2 2
BDR (0Ch) 11 11 11 11 11 11 11
Identify
(80h/C0h) 12 7 7 7 7 7 7
IDE (05h) 5 2 If Retry, 8,
else 5
If Retry, 8,
else 5
If Retry, 8,
else 5
If Retry, 8, if
Status, 2, if
No Status,
5
If Retry, 4,
else 5
Reject (07h) 5 2 2 2 2 2 1
Parity (09h) 5 2 11 11 11 11 If Retry, 4,
else 5
NOP (08h) 5 9 9 9 9 9 If EOM, 9,
else 4
Negotiate 5 10 7 7 7 7 10
Unrecognized
or illegal 5 6 6 6 6 6 If EOM, 6,
else 4
IN Phase during which ATN is raised
Message
Save Data
Pointers
(02h)
Restore
Pointers
(03h)
Disconnect
(04h)
Reject
Message
(07h)
Identify
(80h)
Command
Complete
(00h)
Ignore
Wide
Residue
(23h)
Abort (06h) 2 2 2 2 2 2 2
BDR (0Ch) 11 11 11 11 11 11 11
Identify
(80h/C0h) 7 7 7 7 7 2 7
IDE (05h) If Retry, 4
else 5
If Status, 2,
if No Status,
5
If Retry, 4,
else 5
If Retry, 4,
else 13
If retry, 4,
else 5
2 If retry, 4,
else 5
Reject (07h) 2 If Status, 2,
if No Status,
5
1 2 2 2 2
Parity (09h) If Retry, 4 If Status, 2, If Retry, 4, If Retry, 4, If Retry, 4, 2 If Retry, 4,