Quantum Instruments DLT 7000 - Manual (Page 141)

SCSI Commands
Quantum DLT 7000 Tape System 5-37
LOG SELECT Command (4Ch) (continued)
Table 5–18 LOG SELECT Log Parameters Field Descriptions (continued)
Field Name Description
Parameter Code
(continued) Note: Parameter codes 00h, 01h, and 04h always have a value of 0.
Parameter value for 05h is 8 bytes; the parameter length is set to 8.
DU Disable Update. This bit is not defined for LOG SELECT; the target ignores any
value in DU.
DS Disable Save. Not supported. Must be set to 1.
TSD Target Save Disable. Not supported. Must be set to 1.
ETC Enable Threshold Comparison. When set to 1, drive performs a comparison
with threshold values once the cumulative value is updated. Comparison
criteria are defined in Threshold Met Criteria (TMC). If the comparison is met
and the RLEC bit of MODE SELECT / SENSE Control Page 0Ah is set to 1, then a
UNIT ATTENTION is generated for all initiators. The additional sense code is set
to THRESHOLD CONDITION MET. If the RLEC bit is 0 and the comparison is
met, then UNIT ATTENTION is not generated.
TMC Threshold Met Criteria. Once the criteria specified in this field is met and the
ETC bit is 1 and the RLEC bit in MODE SENSE / SELECT Control Page is set to 1,
then UNIT ATTENTION is generated for all initiators.
The criteria for comparison are:
Code - Basis of Comparison
00b - Every update of the cumulative value
01b - Cumulative value equal to threshold value
10b - Cumulative value not equal to threshold value
11b - Cumulative value greater than threshold value
The Default Threshold Values are the maximum values that each parameter
can attain.