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SONY SDT-10000/SDT-11000 DDS Tape Drive
5. SCSI INTERFACE
5. 4 STATUS SPECIFICATION
A Status byte is sent from the drive to the Host during the STATUS phase at the termination of each command as
specified in the SCSI specification, unless the command has been cleared by an ABORT message, by a BUS DEVICE
RESET message, or by a hard RESET.
The Status bytes that will be return are:
00h
GOOD: This status indicates that the drive has successfully completed the command.
02h
CHECK CONDITION: Any error, exception, or abnormal condition that causes sense data to be set returns
CHECK CONDITION. The REQUEST SENSE command should be sent following this status to determine the
nature of the error.
08h
BUSY: The drive is busy. This status is returned whenever the drive is unable to accept a command from an
otherwise acceptable initiator.
The BUSY status will be returned by the unit, if, while it is DISCONNECTED from the SCSI bus, it receives a
command from a different initiator. The unit does not stack commands and therefore will not accept the next
command until the current one has completed. Note that if an initiator sends overlapped commands to the unit
(i.e.: it sends a new command while the previous one is still executing and the unit is disconnected) then the first
command will be aborted and a CHECK CONDITION will be returned to the initiator to indicate that the
command was aborted. The second command will NOT be executed.
The BUSY status returned by the drive must not be confused with DRIVE NOT READY. DRIVE NOT
READY will be returned as part of the Sense data following a REQUEST SENSE command and indicates that
the drive is offline and no media is loaded in the drive.
The drive is deemed offline if the tape is currently unloaded and, normally, ejected from the drive. However,
the drive will still be offline if the tape has been retained within the drive following a Host issued PREVENT
MEDIA REMOVAL command prior to the unload.
In the offline state, the Host cannot perform any operation which would cause tape motion. These commands
will return a CHECK CONDITION status with a DRIVE NOT READY sense key set. The command types
which are not allowed are write, read, verify or space commands. The Host may load the tape when the unit is
offline so long as the tape has been prevented from being ejected via the PREVENT/ALLOW MEDIA RE-
MOVAL command.
Summary of Contents for DDS-4
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