function TDA2.QueryOrganization(out pNameSpaceType:OPCNAMESPACETYPE):HResult;stdcall;
begin
 pNameSpaceType:=OPC_NS_FLAT;
 result:=S_OK;
end;

function TDA2.ChangeBrowsePosition(dwBrowseDirection:OPCBROWSEDIRECTION;
                              szString:POleStr):HResult;stdcall;
begin
 result:=E_FAIL
end;

function TDA2.BrowseOPCItemIDs(dwBrowseFilterType:OPCBROWSETYPE; szFilterCriteria:POleStr;
                          vtDataTypeFilter:TVarType; dwAccessRightsFilter:DWORD;
                          out ppIEnumString:IEnumString):HResult;stdcall;
var
 i:integer;
 tList:TStringList;
begin
//add filter support
 result:=S_OK;
 tList:=nil;
 try
  tList:=TStringList.Create;
  if tList = nil then
   begin
    result:=E_OUTOFMEMORY;
    Exit;
   end;

  for i:= low(posItems) to high(posItems) do
   tList.Add(posItems[i].tagname);

  ppIEnumString:=TOPCStringsEnumerator.Create(tList);
 finally
  tList.Free;
 end;
end;

function TDA2.GetItemID(szItemDataID:POleStr; out szItemID:POleStr):HResult;stdcall;
var
 propID:integer;
begin
 result:=S_OK;
 if length(szItemDataID) = 0 then
  szItemID:=StringToLPOLESTR(szItemDataID)
 else
  begin
   propID:=ReturnPropIDFromTagname(szItemDataID);
   if propID = 0 then
    result:=OPC_E_UNKNOWNITEMID
   else
    szItemID:=StringToLPOLESTR(szItemDataID);
  end;
end;

function TDA2.BrowseAccessPaths(szItemID:POleStr; out ppIEnumString:IEnumString):HResult;stdcall;
begin
 result:=E_NOTIMPL;
end;