
132 Commands
■ DEFERRED ERROR sense
Unless otherwise stated, all the following descriptions apply to the sense data
for a single host whose command is being executed.
Current Sense
Current sense is the data that is returned in response to a REQUEST SENSE
command. It is modified or updated in the following circumstances:
■ It is cleared in response to the arrival of any command other than REQUEST
SENSE
or INQUIRY.
■ It is cleared following execution of a REQUEST SENSE command.
■ If the current command fails, sense is set according to the failure and
CHECK CONDITION is reported to the host that sent the command.
■ If the previous command terminated with an unexpected BUS FREE, current
sense is set according to the reason for the bus release.
■ If the command fails its pre-execution check for Unit Attention, UNIT
ATTENTION
sense is copied to the Current sense, and CHECK CONDITION is
reported to the host that sent the command.
■ If the command fails its pre-execution check for Deferred Error, DEFERRED
ERROR
sense is copied to the Current sense, and CHECK CONDITION is
reported to the host that sent the command.
Clearing Current Sense:
Clearing the Current sense involves setting sense fields as follows:
Valid = 0
error code = 0x70
segment number = 0
ILI = 0
sense key = 0
information bytes = 0
command specific information = 0
fru code = 0
SKSV = 0
UNIT ATTENTION Sense
UNIT ATTENTION sense is set when one of the following Unit Attention
conditions occur: