6.Command Specification
LOG SENSE
6-16
SONY AIT-3Ex drive SDX-800V series Ver.1.0
TSD:
A target save disable (TSD) bit of ZERO indicates a target-defined method for saving log parameters. This
implicit saving operation shall be done frequently enough to insure that the cumulative parameter values retain
statistical significance (i.e. across power cycles). A TSD bit of one indicates that either the target does not provide a
target-defined method for saving log parameters or the target-defined method has been disabled by the initiator. If
the initiator sets both the DS and the TSD bits set to one, the target shall terminate the command with CHECK
CONDITION status. The sense key shall be set to ILLEGAL REQUEST with the additional sense code set to
INVALID FIELD IN PARAMETER LIST.
ETC:
An enable threshold comparison (ETC) bit of one indicates that when the cumulative parameter value is
updated, it shall be compared to the threshold parameter value and the action specified by the TMC field shall be
taken. An (ET) bit of ZERO disables this comparison. The ET bit is the same for both the cumulative and threshold
log parameter. Thus when the ET bit is set to a value by the initiator, this value is returned for both the cumulative
and threshold values of the log parameter.
TMC:
The threshold met criteria (TMC) field defines the binary relationship between the cumulative and threshold
log parameter values under which the threshold is met. If the ET bit is one and the threshold condition is met, a Unit
Attention condition shall be posted to all initiators. When reporting the unit attention condition, the target shall set the
sense key to UNIT ATTENTION, the additional sense code to LOG EXCEPTION, and the additional sense code
qualifier to THRESHOLD CONDITION MET.
The TMC field is the same for both the cumulative and threshold parameter. Thus when the TMC field is set to a
value by the initiator, this value is returned for both cumulative and threshold values of the log parameter.
Table 6-12: Threshold Met criteria
TMC
Threshold Met Criteria
00b
01b
10b
11b
Any update of the parameter
Cumulative = Threshold
Cumulative < > Threshold
Cumulative > Threshold
LP:
The LP bit field defines whether the parameter is a data counter or a list parameter. See the description of each
supported page below for information on the setting of this field.
Note:
If any of the other bit-fields in the control byte are set then the command will terminate with a CHECK
CONDITION status with a sense key of ILLEGAL REQUEST and an additional sense code of INVALID FIELD IN
PARAMETER LIST
6.6.3. Supported Log Pages
The following log pages are supported:
Table 6-13: Supported Log pages
Page Code
Description
00h
02h
03h
07h
2Eh
30h
31h
33h
34h
35h
39h
3Ch
3Dh
3Eh
Supported Log Pages
Write Error Counter Page
Read Error Counter Page
Last n Error Events Page
Tape Alert Log Page
Tape Log Page (Sony Unique)
Tape Capacity Log Page
Drive Usage Log Page (Sony Unique)
Write Frame Error Counter Page
Read Frame Error Counter Page
Transfer Log Page
AIT Log Page
AIT Fixed Length Information Page for MIC
AIT Variable Length Information Page for MIC
A description of each supported log page is given below.
