Quantum Instruments DLT 7000 - Manual (Page 145)

SCSI Commands
Quantum DLT 7000 Tape System 5-41
LOG SENSE Command (4Dh) (continued)
Table 5–19 LOG SENSE Command Descriptor Block - Field Descriptions (continued)
Field Name Description
Page Code The Page Code field identifies which log page is being requested by the initiator.
If the page is not supported, then the command terminates with a CHECK
CONDITION status, sense key set to ILLEGAL REQUEST, and additional sense code
of INVALID FIELD IN CDB. Supported pages are:
Page Code Page Definition See Section
00h List of Supported Pages Page 5.8.2
02h Write Error Counter Page 5.8.3
03h Read Error Counter Page 5.8.3
07h Last n Errors Events Page 5.8.4
2Eh TapeAlert Page 5.8.5
32h Compression Ratio Page 5.8.6
33h Device Wellness Log Page 5.8.7
3Eh Device Status Log Page 5.8.8
Parameter
Pointer The Parameter Pointer field allows the host to specify at which parameter within a
log page the requested data should begin. For example, if a page supports
parameters 0 through 5, and the Parameter Pointer contains 3, then only
parameters 3, 4, and 5 are returned to the initiator. Similarly, if a page supports
parameters 1, 3, and 6, and the Parameter Pointer contains 2, then only
parameters 3 and 6 are returned to the initiator.
If the Parameter Pointer is larger than the highest numbered parameter on the
page, then the target terminates the command with CHECK CONDITION status,
sense key set to ILLEGAL REQUEST, and additional sense code set to INVALID
FIELD IN CDB.
Note that parameters within a page are always returned in ascending order
according to parameter code.
If the target does not support a parameter code within this page then it does not
return any data associated with this parameter.
Allocation
Length The Allocation Length field is used to inform the target how much space the
initiator has allocated for data. The host uses this field to limit the size of data
transfers to its own internal buffer size.