User's Manual

DLT4000 SCSI Interface
8 3
8 2. Unit Attention Condition
Queued Unit Attentions are implemented on this device, and are maintained
following circumstances:
•
• BUS Reset
Bus Device Reset message
• media may have changed asynchronously
•
• A firmware (microcode) update has completed
a cartridge is loaded, Power Up and Not-ready to Ready Transition Unit Attentions are
created. Due to a limited number of Unit Attention buffers, if an initiator does not
new Unit Attentions for that I-L combination (but existing ones will be left queued).
A LOAD command will not generate a Unit Attention for the initiator that issued the
8. .5
• All device SCSI lines go to high impedance when the DLT4000 drive is powered
• The DLT4000 drive will not generate any spurious signals on the SCSI bus at
• Within 5 seconds of power on, and within 250 milliseconds (typically under 4 ms)
return appropriate, normal, responses. Tape motion commands will be returned
with Check Condition status, Sense Key Not Ready, until the media has been
• The Hard Bus Reset option is implemented.
The media is rewound to BOP (Beginning of Partition, i.e. Beginning of Tape).
resets of arbitrarily long duration. It will recover within the time limits specified
above, following the last bus reset.