User's Guide
Chapter 3 Emulated DLT7000 SCSI Commands
Request Sense (03h)
Quantum DX-Series Software Interface Guide 247
Request Sense (03h) 3
The REQUEST SENSE command causes the tape drive to transfer 
detailed sense data to the initiator.
Table 199 REQUEST 
SENSE Command 
Descriptor Block - 
Data Format
Bit/Byte 7 6 5 4 3 2 1 0
0
1
2-3
4
5
Table 200 REQUEST 
SENSE Command 
Data - Field 
Descriptions
The REQUEST SENSE command causes the tape drive to transfer 
detailed sense data to the initiator.
The sense data is valid for a CHECK CONDITION or RESERVATION 
CONFLICT status returned on the previous command. The sense data 
bytes are preserved by the tape drive until retrieved by a REQUEST 
SENSE command, or until the receipt of any other command from the 
same initiator, though some commands, such as INQUIRY, do not change 
sense data.
If the tape drive receives an unsolicited REQUEST SENSE, it returns 
sense data with the appropriate values in the End of Media (EOM), Sense 
Key, Additional Sense Code, and Additional Sense Code Qualifier. The 
positional information provided reflects the logical position of the tape 
Operation Code (03h)
Logical Unit Number Reserved
Reserved
Allocation Length
Unused Reserved Flag (0)Link (0)
Field Name Description
Allocation 
Length
This field specifies the maximum number of sense 
bytes to be returned. The tape drive terminates the 
transfer when this number of bytes has been 
transferred or when all available sense data has 
been transferred to the host, whichever is less.










