User's Guide

Page 56 DDS-4 SCSI Interface Manual, Rev. B
set to Log Exception; and the additional sense code qualifier is set to Threshold
Condition Met, 5B/01.
If the counter is disabled because the DU bit is set (1), no threshold conditions are
compared because the counter will not be incremented.
After the log exception is signaled by the Check Condition, the host may issue the
LOG SENSE command to determine which page and which counter (by parameter
code) met the criteria or may read the sense key specific field in the REQUEST
SENSE data.
The criteria for generating a Check Condition are specified by the TMC field in bits 2
and 3 of byte 2 of the parameter header. The possible settings and resulting
operation are as follows.
TMC Field Bits
3 2 Generate a Log Exception Check Condition
0 0 Whenever the accumulated value is incremented.
0 1 When the accumulated value equals the threshold.
1 0 Whenever the accumulated value does not equal the
threshold.
1 1 Whenever the accumulated value is greater than the
threshold value. This setting is the default value