This object selects how the sampled variable's value is calculated for threshold comparison: absoluteValue(1, the default, compares the raw sampled value) or deltaValue(2, compares the difference from the previous sample); it cannot be modified once the entry's status is valid. Admins choose deltaValue for ever-increasing counters like error counts, so the alarm reacts to the rate of change rather than the cumulative total. Setting this to deltaValue(2) on an interface error counter makes the alarm compare how many new errors occurred during each interval, rather than the running total.