DLT1/VS80 SCSI Interface Guide
81-81276-01 Rev A01
July 2004
2-5
2.8.2 STATUS Phase
The tape drive enters the STATUS phase only once per command unless the initiator requests a retry.
The sole exception to this behavior is during error cases when the drive goes immediately to BUS
FREE, as defined in the SCSI-2 standard.
The tape drive returns the following STATUS bytes:
•
GOOD (00h): This status indicates the tape drive successfully completed the command.
•
CHECK CONDITION (02h): A contingent allegiance condition occurred. The REQUEST SENSE
command should be sent following this status to determine the nature of the event.
•
BUSY (08h): The target is busy. The tape drive returns this status whenever the tape drive is
unable to accept a command from an otherwise acceptable initiator. The initiator should reissue the
command at a later time.
•
INTERMEDIATE GOOD (10h): The tape drive returns this status instead of GOOD status for
commands issued with the LINK bit set. Following the return of this status, the tape drive proceeds
to the COMMAND phase for the transfer of the next linked command.
•
RESERVATION CONFLICT (18h): The tape drive returns this status whenever one initiator (a
SCSI tape drive) attempts to access the tape drive when another initiator has reserved the tape
drive with a RESERVE UNIT command.
•
COMMAND TERMINATED (22h): The tape drive returns this status for a command that a
TERMINATE I/O PROCESS message has terminated. This status also indicates that a contingent
allegiance condition has occurred.
N
OTE
:
In contrast to the BUSY status condition, the tape drive returns the
DRIVE NOT READY Sense Key as part of the Sense data following a
REQUEST SENSE command. This indicates that an initiator has issued a
data cartridge access command and the data cartridge is not ready to be
accessed. For example, the data cartridge is not installed, the data
cartridge has been unloaded, the tape drive is currently initializing the
data cartridge to prepare it for access, and so forth.
When the tape drive is in the “not ready” state, the initiator cannot perform any operation that would
cause medium motion, for example, write, read, space, verify, etc. If the initiator attempts any of these
commands, the tape drive returns a CHECK CONDITION status with a DRIVE NOT READY sense
key. The initiator may, however, execute commands that do not require access to the data cartridge and
the tape drive may return a GOOD status.
Summary of Contents for DLT1/VS80 SCSI
Page 1: ...DLT1 VS80 SCSI Interface Guide...
Page 6: ...DLT1 VS80 SCSI Interface Guide vi July 2004 81 81276 01 Rev A01 Notes...
Page 12: ...Table of Contents xii July 2004 81 81276 01 Rev A01 Notes...
Page 16: ...List of Figures xiv July 2004 81 81276 01 Rev A01 Notes...
Page 20: ...List of Tables xviii July 2004 81 81276 01 Rev A01 Notes...
Page 24: ...Chapter 1 Introduction 1 4 July 2004 81 81276 01 Rev A01 Notes...
Page 32: ...Chapter 2 General SCSI Bus Operation 2 8 July 2004 81 81276 01 Rev A01 Notes...
Page 42: ...Chapter 3 SCSI Messages 3 10 July 2004 81 81276 01 Rev A01 Notes...
Page 181: ......
