C141-E039-01EN
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1.5.2
Response to the UNIT ATTENTION Condition Hold State and Cancellation Conditions
A UNIT ATTENTION condition generated by the IDD by the occurrence of the previously
mentioned events is held individually for each INIT and it is held until it is cleared by the INIT
it is held for issuing the commands specified below.
When the IDD is holding a UNIT ATTENTION condition, if the IDD receives a command
from the INIT that the UNIT ATTENTION condition is held for, it performs one of the
following operations depending on the type of command issued.
(1)
Commands other than the INQUIRY and REQUEST SENSE Commands
The IDD reports a CHECK CONDITION status for the command that is issued. The UNIT
ATTENTION condition for that INIT is then cleared by the CHECK CONDITION status
report. The sense key of the sense data generated at this time is UNIT ATTENTION [=6] and
the sense codes shown below indicate the event that generated the UNIT ATTENTION
condition.
•
Power-on, RESET, or BUS DEVICE RESET occurred [=29-00]
•
Mode parameters changed
[=2A-01]
•
Log parameters changed
[=2A-02]
•
Commands cleared by another INIT
[=2F-00]
•
Threshold condition met
[=5B-01]
•
Log counter at maximum
[=5B-02]
•
Spindle synchronized
[=5C-01]
•
Spindle not synchronized
[=5C-02]
However, if the IDD responds with a BUSY status or QUEUE FULL status due to its not
being able to receive the command that was issued, the UNIT ATTENTION condition is not
cleared.
The above CHECK CONDITION status response that is the cause of the UNIT ATTENTION
condition hold can be prohibited by the specification of the CHANGE DEFINITION
command. When the CHECK CONDITION status response is prohibited, the IDD executes
the commands it receives normally, except in the case of a RESERVATION CONFLICT
status, BUSY status or QUEUE FULL status. In this case, the UNIT ATTENTION condition
for the INIT that issued that command is cleared.
See 3.1.4 “CHANGE DEFINITION” concerning setting details.
(2)
INQUIRY Command
The INQUIRY command is executed normally, but the UNIT ATTENTION condition is not
cleared.
