def __init__(self, string='', function_code=None):
    ' Initialize the exception\n        :param string: The message to append to the error\n        '
    self.fcode = function_code
    self.message = ('[Input/Output] %s' % string)
    ModbusException.__init__(self, self.message)
Initialize the exception
:param string: The message to append to the error
def __init__(self, string=, function_code=None):
    ' Initialize the exception\n        :param string: The message to append to the error\n        '
    self.fcode = function_code
    self.message = ('[Input/Output] %s' % string)
    ModbusException.__init__(self, self.message)