A CwrThreshLimitType, read-create, specifying the kind of change condition, such as a high, low, or delta crossing, applied to cwrThreshAttribute. This determines the actual comparison logic the agent uses against cwrThreshValue before it decides whether to fire a notification. For example, choosing a downChange type means a trap fires only when the monitored attribute drops by more than cwrThreshValue, not simply because it is low.