Need to write values to OPC HDA|Classic OPC: DA, A&E, HDA, XML-DA, etc.|Forum|OPC Foundation

Hi Nathan,

I have a requirement where I am writing historical values back to the OPC HDA. I see how it is done in the DA but I guess it will not be the same. I am trying the below code but it doesnt seem to do a “replace”. Please can you help me out here.

  Opc.ItemIdentifier identifier = new Opc.ItemIdentifier(“Saw-toothed Waves.Int1”); //Tag
            
            
            Opc.Hda.ItemValue item = new Opc.Hda.ItemValue();
            
            item.Value = 777; // This is the value i want to write
            item.Quality = Opc.Da.Quality.Good;
            item.Timestamp = new DateTime(2017, 05, 24, 16, 13, 20,017);

            Opc.Hda.ItemValueCollection collection = new Opc.Hda.ItemValueCollection(identifier);
            collection.Add(item);

            List<Opc.Hda.ItemValueCollection> coll = new List<ItemValueCollection>();
            coll.Add(collection);          
            
            
          ResultCollection[] cll =  _hdaServer.Replace(coll.ToArray()); //This doesnt work it gives me an INVALIDRESPONSE exception.

Please help me out

-Yatindra