oTView.TimeZoomMinForCompress = n
If the current range of the time axis (TimeMax - TimeMin) exceeds the value TimeZoomMinForCompress and the number of points stored by the trend server (by the PmTrend object) exceeds the value PointsMaxVisibleCount in this range, then the trend server provides the evaluation of values, and only the PointsMaxVisibleCount points are returned to the viewer calculated according to CompressType. The trend server creates the data in the response to the query as follows: The range of the time axis is divided into the same time interval with the length (TimeMax - TimeMin)/PointsMaxVisibleCount and in each such interval a new point is calculated by the CompressType method and the set of such calculated points is returned to the viewer.
var oTView = pMe.Acx;
oTView.TimeZoomMinForCompress = 1/24;
oTView.TimeZoomMinForCompress = "1.5hour";
oTView.TimeZoomMinForCompress = "1hour30min";