Disconnect/Reconnect Function - Quantum LTO 2 User Manual

Disconnect/Reconnect
Function
LTO-2 SCSI Interface Guide
• DT data transfers with CRC protection running a max rate of
160Mbytes/sec
• 16 bit SCSI arbitration
• Disconnect/reconnect
• Hard reset
When the drive is performing a task not requiring communication with
the Initiator or when the tape drive determines that a relatively long time
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has passed with no bus activity, it disconnects from the SCSI bus.
Examples are:
• When rewinding the tape.
• When writing to the tape and the buffer is full.
• When reading from the tape and the buffer is empty.
• When spacing, locating, or generally performing any tape motion
when data cannot be transferred on the SCSI bus.
During the time the Target is disconnected for one of these functions, the
bus is free for use by other devices. Both disconnect and reconnect are
initiated by the Target.
If the tape drive is selected while disconnected, it only allows the
following actions:
• If the command is from a different initiator or is from the same
initiator but to a different LUN, the tape drive accepts the command
and immediately disconnects if the command is a media-access
command. If the new command is a
TEST UNIT READY
• Immediately following the selection, the Initiator may send the
Identify, No Op, Abort, or Bus Device Reset messages to the drive.
• If the command is from the same initiator to the same LUN, the
current command terminates with a Check Condition and an Abort
Sense Key.
REQUEST SENSE
, then the new command is executed immediately.
Chapter 1 SCSI Interface
Parallel SCSI Interface
, or
INQUIRY
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