title: Hang reading a serial port with Python and pyserial
body: <p>Correction -- I'm using the first tty -- not 5 as the old version stated.</p>
  
  <p>I'm in the process of writing a program to allow a TS-4200-8160 embedded arm computer to respond to serial data.  My first step is to log some serial data. So I have been testing a serial logging script for the TS-4200-8160. The script starts well, collecting individual characters, then hangs on the read after collecting tens of characters (so it does work for a while):</p>
  
  <pre><code>import serial
  from datetime import datetime
  import time, struct
  import sys
  
  
  def fileout(mesg):
      with open('/root/python/rs485cap.out', 'a') as f:
      f.write(mesg)
  
  def main():
      ser = serial.Serial( 
          port=0, 
          baudrate=115200, 
          parity=serial.PARITY_NONE, 
          stopbits=serial.STOPBITS_ONE, 
          bytesize=serial.EIGHTBITS, 
          timeout=None
      ) 
  
      try:
          while 1:
          print ser.portstr
          stuff=ser.read()
          fileout(stuff + ", "+str(datetime.now()) + '\n')
           print stuff
  
  
      except KeyboardInterrupt:
          print "Bye"
          ser.close()
          sys.exit()
          ser.close() 
  
       ser.close()
  
  
  if __name__ == '__main__':
  main()
  </code></pre>
  
  <p>What is missing?  Thanks for your help!</p>