Traceback (most recent call last): File "roboclaw_simplepwm.py", line
  14, in rc.ForwardM1(address,32) #1/4 power forward File
  "/home/devchu/dev/roboclaw_python/roboclaw_python/roboclaw.py", line
  647, in ForwardM1 return self._write1(address,self.Cmd.M1FORWARD,val)
  File "/home/devchu/dev/roboclaw_python/roboclaw_python/roboclaw.py",
  line 311, in _write1 self._sendcommand(address,cmd) File
  "/home/devchu/dev/roboclaw_python/roboclaw_python/roboclaw.py", line
  126, in _sendcommand self._port.write(chr(address)) **AttributeError:
  Roboclaw instance has no attribute '_port'**