procedure TOPCThreadReader.Read;
VAR
  Arguments: OleVariant;
  Results: OleVariant;
  WriteResult: _ValueResult;
  res: string;
  i: integer;
  Value : Variant;
begin
  ReadArguments.EndpointDescriptor.UrlString :=
    'opc.tcp://920-11-01-003:4840';
 
    changer := false;
    ReadArguments.NodeDescriptor.NodeId.ExpandedText :=
      'ns=4;s=MAIN.Modul1_Gewicht';
  Position_Read:=1;
  Arguments := VarArrayCreate([0, 0], varVariant);
  Arguments[0] := ReadArguments;
 
  Position_Read:=2;
  TVarData(Results).VType := vararray or varVariant;
  Position_Read:=3;
  TVarData(Results).VArray :=
    PVarArray(Client.readmultiplevalues(PSafeArray(TVarData(Arguments)
    .VArray)));
  Position_Read:=4;
 
  for i := VarArrayLowBound(Results, 1) to VarArrayHighBound(Results, 1) do
  begin
    WriteResult := IInterface(Results[i]) as _ValueResult;
    if WriteResult.Succeeded then
    begin
      Value:=WriteResult.value;
      Rueckgabe:=formatfloat('0.000',value);
      Position_Read:=5;
    end
    else
    begin
      res := ReadArguments.NodeDescriptor.NodeId.ExpandedText + ':' +
        WriteResult.Exception.GetBaseException.Message;
     Rueckgabe:=res;
     Position_Read:=6;
    end;
  end;
 
  Varclear(Arguments);
end;

procedure TOPCThreadChange.subscribe;
var
  i: integer;
  Arguments: OleVariant;
  // Handle: Cardinal;
  HandleArray: OleVariant;
  MonitoredItemArguments: array of _EasyUAMonitoredItemArguments;
  laenge: integer;
  Position: integer;
begin
  try
    laenge:=1;
    MonitoringParameters := CoUAMonitoringParameters.Create;
 
    MonitoringParameters.SamplingInterval := 100;
    setlength(MonitoredItemArguments, laenge);
 
    for i := 0 to laenge - 1 do
    begin
      MonitoredItemArguments[i] := CoEasyUAMonitoredItemArguments.Create;
      MonitoredItemArguments[i].EndpointDescriptor.UrlString :=
         'opc.tcp://920-11-01-003:4840';
      MonitoredItemArguments[i].NodeDescriptor.NodeId.ExpandedText :=
        'ns=4;s=MAIN.Modul1_Gewicht';
      MonitoredItemArguments[i].MonitoringParameters := MonitoringParameters;
    end;
 
    Arguments := VarArrayCreate([0, laenge - 1], varVariant);
    for i := 0 to laenge - 1 do
    begin
      Arguments[i] := MonitoredItemArguments[i];
    end;
    TVarData(HandleArray).VType := vararray or varVariant;
    TVarData(HandleArray).VArray :=
      PVarArray(Client.SubscribeMultipleMonitoredItems
      (PSafeArray(TVarData(Arguments).VArray)));
 
  except
 
  end;
 
end;