procedure TForm1.OPCServerDatachange(Sender: TObject; ItemList: TdOPCItemList); var i: integer; Item : TdOPCItem; begin for i := 0 to ItemList.Count-1 do //more than one item possible begin Item := ItemList[i]; Memo1.Lines.Add(format('Item %s Value %s', [Item.ItemId,Item.ValueStr])); end; end;