code: def read(self, client):
          
          assert(isinstance(self._bytearray, DB))
          assert(self.row_size >= 0)
          db_nr = self._bytearray.db_number
          _bytearray = client.db_read(db_nr, self.db_offset, self.row_size)
  
          data = self.get_bytearray()
          # replace data in bytearray
          for i, b in enumerate(_bytearray):
              data[i + self.db_offset] = b
docs: read current data of db row from plc