code: def ab_read(self, start, size):
          
          wordlen = snap7.snap7types.S7WLByte
          type_ = snap7.snap7types.wordlen_to_ctypes[wordlen]
          data = (type_ * size)()
          logger.debug("ab_read: start: %s: size %s: " % (start, size))
          result = self.library.Cli_ABRead(self.pointer, start, size,
                                           byref(data))
          check_error(result, context="client")
          return bytearray(data)
docs: This is a lean function of Cli_ReadArea() to read PLC process outputs.