Commands152
Descriptor format
The Descriptor format of the returned data is as follows:
Returned Sense data fields:
7 6 5 4 3 2 1 0
0 Valid Response Code
1 Reserved(0) Sense Key
2 Additional Sense Code
3 Additional Sense Code Qualifier
4–6 Reserved (0)
7 Additional Sense Length (n–7)
8 (MSB)
Sense Data Descriptor 0
: (LSB)
:
:
Sense Data Descriptor X
n
Response Code 72h The error is current, that is, it is associated with the command for which
CHECK CONDITION status has been reported.
73h The error is deferred. A deferred error occurs when there is a failure for an
operation that has already been terminated with a GOOD status, or when
failure occurs in “cleanup” activity following an operation that was
terminated by BUS RELEASE. The command for which
CHECK CONDITION
status was reported is therefore unlikely to be the cause of the deferred error.
It simply gives the drive the opportunity to report CHECK CONDITION status
for an error that already exists.
Additional Sense
Length
The number of additional sense bytes to follow, ≤244. It is never truncated to reflect
the actual Transfer Length.
Additional Sense
Code and Qualifier
Additional information about the cause of the
CHECK CONDITION, or the current
tape position when the REQUEST SENSE is unsolicited. See “Additional Sense
Codes” on page 159.
Sense Data
Descriptor
At least one descriptor is sent (Drive Error Code), the others may or may not be sent
depending on the nature of the CHECK CONDITION.
