Opc.Ua.Sample.Program.HistoryReadProcessed C# (CSharp) Method

        static void HistoryReadProcessed(Session session)
        {
            // translate browse paths.
            IList<NodeOfInterest> nodeIds = GetNodeIds(session, Opc.Ua.Objects.ObjectsFolder, 
                VariableBrowsePaths.ToArray());

            DiagnosticInfoCollection diagnosticInfos;

            NodeId aggregateNodeId = null;

            RequestHeader rh = null;
            ViewDescription vd = null;
            ReferenceDescriptionCollection references;
            byte[] cp;

            //Get the list of avalilable aggregate functions:
            session.Browse(
                rh, 
                vd, 
                Opc.Ua.ObjectIds.Server_ServerCapabilities_AggregateFunctions,
                1000,
                BrowseDirection.Forward, 
                ReferenceTypeIds.Aggregates, 
                false, 
                0, 
                out cp, 
                out references);

            Console.WriteLine("{0} aggregates are detected:", references.Count);

            //Print the list of avalible aggregates:
            int i = 0;
            foreach (ReferenceDescription rd in references)
            {
                i++;
                Console.WriteLine("{0}. {1} {2}", i, rd.BrowseName, rd.NodeId.Identifier.ToString());
            }

            //Select aggregate function:
            Console.WriteLine("\nEnter aggregate number: ");
            string str = Console.ReadLine();

            i = System.Int16.Parse(str);

            if (i > 0 && i <= references.Count)
            {
                aggregateNodeId = ExpandedNodeId.ToNodeId(references[i - 1].NodeId, session.NamespaceUris);
            }

            //Prepare arguments to pass to read processed history
            ReadProcessedDetails readDetails = new ReadProcessedDetails();

            readDetails.StartTime = new DateTime(2008, 1, 1, 12, 0, 0);
            readDetails.EndTime = new DateTime(2008, 1, 1, 12, 0, 12);

            readDetails.AggregateType = new NodeIdCollection(nodeIds.Count);
            for (int x = 0; x < nodeIds.Count; x++)
            {
                readDetails.AggregateType.Add (aggregateNodeId);
            }

            readDetails.ProcessingInterval = 500; //500 milliseconds

            ExtensionObject eo = new ExtensionObject(readDetails.TypeId, readDetails);

            HistoryReadValueIdCollection idCollection = new HistoryReadValueIdCollection();
            for (int ii = 0; ii < nodeIds.Count; ii++)
            {
                HistoryReadValueId readValueId = new HistoryReadValueId();
                readValueId.NodeId = nodeIds[ii].NodeId;
                readValueId.Processed = true;
                idCollection.Add(readValueId);
            }

            HistoryReadResultCollection historyReadResults;

            //Read processed history:
            ResponseHeader responseHeader =
                session.HistoryRead(null, eo, TimestampsToReturn.Both, true,
                idCollection, out historyReadResults, out diagnosticInfos);

            //Print results:
            for (int ii = 0; ii < historyReadResults.Count; ii++)
            {
                HistoryReadResult historyReadResult = historyReadResults[ii];
                ServiceResult result = Session.GetResult(historyReadResult.StatusCode, ii, diagnosticInfos, responseHeader);
                
                HistoryData historyData = null;
                DataValueCollection dataValues = null;
                if ( !(historyReadResult.HistoryData == null) )
                {
                    historyData = ExtensionObject.ToEncodeable(historyReadResult.HistoryData) as HistoryData;
                    if (historyData == null)
                        dataValues = null;
                    else
                        dataValues = historyData.DataValues;
                }

                Console.WriteLine("\nHistoryRead result code for {0}:  {1}", VariableBrowsePaths[ii], result.StatusCode.ToString());

                if (dataValues == null)
                {
                    Console.WriteLine("dataValues == null");
                    continue;
                }

                for (int jj = 0; jj < dataValues.Count; jj++)
                {
                    DataValue dataValue = dataValues[jj];
                    if (dataValue == null)
                        continue;

                    // write value.
                    Console.WriteLine("{0}: V={1}, Q={2}, SrvT={3}, SrcT={4}", jj,
                        dataValue.Value == null ? "null" : dataValue.Value.ToString(),
                        dataValue.StatusCode.ToString(),
                        dataValue.ServerTimestamp, dataValue.SourceTimestamp);
                }
            }
        }