Serial connection error using FTDI with NexStar

[bgottula]

I occasionally encounter a serial error when using the NexStar class. The circumstances leading to it are not entirely clear, but most recently it occurred after completing an alignment. Re-starting the application does not seem to fix it. I have resorted to disconnecting and re-connecting my USB FTDI device which then causes it to show up as a different tty (/dev/ttyUSB1 instead of the initial /dev/ttyUSB0).

Error message:

File "/home/rgottula/dev/point/nexstar.py", line 133, in slew_var
    self._send_command(command)
  File "/home/rgottula/dev/point/nexstar.py", line 40, in _send_command
    response = self.serial.read(response_len + 1)
  File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 495, in read
    raise SerialException('device reports readiness to read but returned no data (device disconnected or multiple access on port?)')