Operating instructions

SEPTEMBER 2005 PRELIMINARY MAGNUM 1X7 LTO AUTOLOADER
2-9
SCSI COMMAND PROTOCOL
 Numbers or upper case letters immediately followed by lower-case h (nnh)
are hexadecimal values.
2.4.3 COMMAND STATUS
The autoloader sends one status byte to the initiator at the completion of a
command. The status byte is formatted as follows:
Ta b l e 2 - 4 contains a summary of the status bytes used by the autoloader.
Note: The autoloader may go to the Bus Free phase without reporting status in
response to a command sequence. If this happens, immediately issue a
REQUEST SENSE (03h) command to determine the cause of the
unexpected disconnect.
Status Descriptions
The following are expanded descriptions of the status bytes listed in Ta b l e 2 - 4 .
Good The autoloader returns Good status to indicate that the operation
specified by the CDB completed normally.
Check Condition The autoloader returns Check Condition status to indicate
that an error has occurred while it was executing a command. The autoloader
reports Check Condition status as soon as it detects the error unless it is
disconnected from the SCSI bus. If the autoloader is disconnected, it reports
Check Condition status after the reconnect process.
Examples of situations that result in Check Condition status are listed below:
Bit
Byte
7 6 5 4 3 2 1 0
00 Reserved Status Byte Code
Table 2-4 SCSI command status bytes supported by the autoloader
Status
Hex
Value
Description
Good 00h Indicates that the autoloader successfully completed the operation
specified by the CDB.
Check Condition 02h Indicates an error, exception, or abnormal condition that has caused
sense information to be set.
Busy 08h Indicates that the autoloader is unable to accept a command from an
initiator.
Reservation Conflict 18h Indicates that the elements identified in the command are reserved by
another initiator.