title: qt serial communication, readyRead not emitted
body: <p>I'm communicating with a CameraLink camera using the CameraLink internal virtual COM-Port. I wrote the following code:</p>
  
  <pre><code>serial=new QSerialPort(this);
  connect(serial,SIGNAL(readyRead()),SLOT(readFPN()));
  serial-&gt;setPortName(comPort);
  serial-&gt;setBaudRate(QSerialPort::Baud9600);
  serial-&gt;setStopBits(QSerialPort::OneStop);
  serial-&gt;setParity(QSerialPort::NoParity);
  serial-&gt;open(QIODevice::ReadWrite);
  
  QString comm=QString("r gwbr\r"); //read red channel gain
  serial-&gt;write(comm.toUtf8(),comm.size());
  
  QString comm=QString("r gwbb\r"); //read blue channel gain
  serial-&gt;write(comm.toUtf8(),comm.size());
  
  ... more serial commands
  </code></pre>
  
  <p>The readFPN function does nothing by now except appending the data read to a QByteArray:</p>
  
  <pre><code>void ts4control_calibrationdialog::readFPN()
  {
      resp+=serial-&gt;readAll();
  }
  </code></pre>
  
  <p>But the readFPN-function is never called. I set a breakpoint and the program steps over the write commands without calling the callback. The general communication with the device works in a COM-Port-terminal using the above settings.</p>
  
  <p>What do I have to change to have the signal emitted? Or how can I find out why it isn't working? Any debugging-ideas?</p>