Description: The method of sampling the selected variable and calculating the value to be compared against the thresholds. If the value of this object is absoluteValue(1), the value of the selected variable will be compared directly with the thresholds at the end of the sampling interval. If the value of this object is deltaValue(2), the value of the selected variable at the last sample will be subtracted from the current value, and the difference compared with the thresholds.

If the associated cHcAlarmVariable instance could not be obtained at the previous sample interval, then a delta sample is not possible, and the value of the associated cHcAlarmValueStatus object for this interval will be valueNotAvailable(1).

This object may not be modified if the associated cHcAlarmStatus object is equal to active(1).