The No Change feature works by checking whether a value has changed by more than a specified Deadband, within a specified time Interval.
If the value changes sufficiently within the Interval, ClearSCADA restarts its No Change checking process, from the instance at which it deems the point’s value to have changed sufficiently:
If the point’s value does not change sufficiently throughout the Interval, when ClearSCADA processes the next point value, it will generate a No Change alarm or event for the point. ClearSCADA will also restart its No Change checking process, using the new point value and its update time as the basis. (Any No Change alarm will remain in force until ClearSCADA next detects that the point’s value has changed sufficiently, whereupon it will clear the alarm.)
