code: def write_multiple_coils(slave_id, starting_address, values):
      
      function = WriteMultipleCoils()
      function.starting_address = starting_address
      function.values = values
  
      return _create_request_adu(slave_id, function.request_pdu)
docs: Return ADU for Modbus function code 15: Write Multiple Coils.
  
      :param slave_id: Number of slave.
      :return: Byte array with ADU.