Libnodave not connected to the S7-400 via MPI

[Dima]

Using Visual Stdio2010 C#, 6ES7 972-OB20-0A0 PC Adapter (USB)

code
public static void MainMPI(string NamePort, int AdressMPI)
        {
            int a = 0, b = 0, c = 0, res;
            float d = 0;

            fds.rfd = libnodave.setPort(NamePort, "38400", 'O');
            fds.wfd = fds.rfd;

            if (fds.rfd > 0)
            {
                di = new libnodave.daveInterface(fds, "IF1", localMPI, libnodave.daveProtoMPI, libnodave.daveSpeed187k);
                di.setTimeout(1000000);

                res = di.initAdapter();

                if (res == 0)
                {
                    dc = new libnodave.daveConnection(di, AdressMPI, 0, 0);
                    if (dc.connectPLC() == 0)
                    {
                        res = dc.readBytes(libnodave.daveFlags, 0, 0, 16, null);
                        if (res == 0)
                        {
                            a = dc.getS32();
                            b = dc.getS32();
                            c = dc.getS32();
                            d = dc.getFloat();
                            MessageBox.Show("FD0:" + a.ToString() + "   FD4:" + b.ToString() + "   FD8:" + c.ToString() + "   FD12:" + d.ToString());
                        }
                        else
                            MessageBox.Show("Error" + res.ToString() + "   " + libnodave.daveStrerror(res));
                    }
                    dc.disconnectPLC();
                }
                di.disconnectAdapter();
                libnodave.closePort(fds.rfd);
            }
            else
            {
                MessageBox.Show("Couldn't open serial port " + NamePort);         
            }
        }

di.initAdapter() returns -44?
NamePort = "COM1"
Tried to use NamePort = "USB", then libnodave.setPort return -1?

Help please

[Dima]

adapter in the device manager is defined as a Simatic PC Adapter USB, as it the new model with USB

Help please