[Bug, Issue] IOInterface base raise exception if nothing received
Description
When using serial com, if nothing is received and the target is not found, this exception is thrown:
File "C:\...\spintop_openhtf\plugs\iointerface\comport.py", line 55, in com_target
return self.message_target(*args, **kwargs)
File "C:\...\spintop_openhtf\plugs\iointerface\base.py", line 145, in message_target
contentstring.write(line)
TypeError: string argument expected, got 'NoneType'
How to recreate
Use serial port with target and don't send back anything just wait for the timeout