2.31 Request Sense (03h)
Operation Code is (03h).
The REQUEST SENSE command requests the drive to transfer extended sense data to the
initiator. The drive supports the first 18 bytes of the extended sense data format. The drive will
transfer Allocation Length bytes or 18 bytes, whichever is smaller.
A valid bit of zero indicates that the information field is not as defined in the SCSI-2
standard. A valid bit of one indicates the information field contains valid information as
defined in the SCSI-2 specifications.
FileMk (File mark) if one indicates that the current command has read a file mark.
EOM (End of Medium) if one indicates that an end-of-medium condition exists.
ILI (Incorrect Length Indicator)
An incorrect length indicator bit set to one indicates that the requested logical block length
did not match the logical block length of the data on the medium.
Provides generic categories in which error and exception conditions can be reported. Table
2-31B lists the supported sense keys.
ASC / ASCQ (Additional Sense Codes)/(Additional Sense Code Qualifier)
Additional sense codes and additional sense code qualifier provides further detail
describing the sense key. These codes are listed in Table 2-31C.
Additional Sense Length
Indicates the number of additional sense bytes to follow. If the allocation length of the
command descriptor block is to small to transfer all of the additional sense bytes, the
additional sense length is not adjusted to reflect the truncation.
Command Specific Info
The field contains information that depends on the command which was executed. Further
definition for this field is contained within the command description.
(Sense Key Specific Valid) The sense-key specific field is defined when the sense-key
specific valid (SKSV) bit is one. A SKSV value of zero indicates that this field is not
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