code: def db_read(self, db_number, start, size):
          
          logger.debug("db_read, db_number:%s, start:%s, size:%s" %
                       (db_number, start, size))
  
          type_ = snap7.snap7types.wordlen_to_ctypes[snap7.snap7types.S7WLByte]
          data = (type_ * size)()
          result = (self.library.Cli_DBRead(
              self.pointer, db_number, start, size,
              byref(data)))
          check_error(result, context="client")
          return bytearray(data)
docs: This is a lean function of Cli_ReadArea() to read PLC DB.
  
          :returns: user buffer.