Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E 115
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The DU bit is not defined for threshold values (indicated by the PC field of the Log Sense command
descriptor block) nor for list parameters (indicated by the LP bit). The drive ignores the value of DU bits
in a Log Select command applicable to threshold values or list parameters.
[3] Disable Save (DS). If DS is zero it indicates that the drive shall support (Log Select)/supports (Log Sense
data) saving for that log parameter. The drive shall save/does save the current cumulative and the cur-
rent threshold parameter values in response to a Log Select or Log Sense command with a SP bit of one.
A DS bit of one indicates that the drive shall not/does not support saving that log parameter in response
to a Log Select or Log Sense command with a SP bit of one.
[4] Target Save Disable (TSD). A zero indicates that the drive shall save frequently enough to insure statis-
tical significance. The drive’s method is to save after each thermal calibration, which is once every ten
minutes. A one bit indicates that the drive shall not/does not use its save method.
[5] Enable Threshold Comparison (ETC). A one indicates that a comparison to the threshold value shall be
(Log Select)/is (Log Sense data) performed whenever the cumulative value is updated. A bit of zero
indicates the comparison shall not be/is not performed. The value of the ETC bit is the same for both the
threshold and cumulative parameters.
[6] Threshold Met Criteria (TMC). This field defines the basis for comparison of the cumulative and threshold
values. See Table 5.1.3.2-5 for meanings of values in this field. The TMC field is only valid when the ETC
bit is one.
Table 5.1.3.2-5. Threshold Met Criteria
Code
Basis for Comparison
00b
Notify of every update of cumulative value
01b*
Cumulative value equal to threshold value
10b*
Cumulative value not equal threshold value
11b*
Cumulative value greater than threshold value
*Comparison made at every update of cumulative value.
If the ETC bit is one* and the result of the comparison is true, a unit attention condition is generated for all
initiators. When reporting the unit attention condition the drive sets the sense key to Unit Attention, and
the additional sense code to Threshold Condition Met.
*The RLEC bit (Report Log Exception Condition) in Mode page 0AH
(Table 5.2.1-28) must also be one.
[7] List Parameter (LP). Zero indicates the parameter is a data counter. One indicates that the parameter is
a list parameter. This bit only has meaning for the Log Sense command data-in pages.
Data counters are associated with one or more events. The data counter is updated whenever one of
these events occurs by incrementing the counter value, provided the DU bit is zero. See Note 2 above.
An LP bit of one indicates that the parameter is a list parameter. List parameters are not counters and
thus the ETC and TMC fields shall be set to zero. A list parameter is a string of ASCII graphic codes (i.e.,
code values 20h thru 73h). List parameters are not supported by the drive at this time.
