Operating instructions

2-10
SCSI REFERENCE PRELIMINARY 1012975
CHAPTER 2—OVERVIEW OF THE AUTOLOADER AS A SCSI DEVICE
 You send an Identify message with an invalid LUN followed by a command
other than INQUIRY or REQUEST SENSE.
 You send a command other than INQUIRY or REQUEST SENSE when there
is a pending Unit Attention condition of the autoloader.
 The autoloader has an unrecoverable hardware error and receives a motion
command.
 The autoloader is not ready when it receives a motion command.
 You set a reserved field to a value other than 0 in the CDB or the parameter
list for the requested command.
 You specify an invalid parameter in the CDB or parameter list for the
requested command.
 The command fails for one of the reasons listed in the command chapter. For
example, a MOVE MEDIUM command terminates with Check Condition
status if the source for the move is empty.
 For specific situations that return Check Condition status, refer to the
command descriptions in Chapter 4 through Chapter 25.
Busy The autoloader returns Busy status to any initiator that sends a
command other than INQUIRY or REQUEST SENSE when the autoloader is
disconnected from the SCSI bus or when it is waiting for a SCSI motion
process to be aborted.
 If allowed, the autoloader disconnects from the SCSI bus when performing
any lengthy operations, such as a move operation.
 The autoloader aborts motion processes in response to an Abort Task Set
message from the initiator that requested the motion command. The
autoloader has to abort the motion process completely before it can process
commands other than INQUIRY and REQUEST SENSE.
Reservation Conflict The autoloader returns Reservation Conflict status to
indicate that either the entire autoloader or the elements requested to be
accessed are currently reserved by another initiator. This status is reported
until the initiator that reserved the autoloader or elements issues a RELEASE
(17h or 57h) command or a reset condition occurs.
2.4.4 COMMAND FORMAT ERRORS
A command format error may occur when:
 The Operation Code in the CDB is not supported by the autoloader.
 The value of the bytes or bits in a Reserved field (as defined by the SCSI
standard) is not 0.