def read_value(self, offset=<NUM_LIT:0>):
try:<EOL><INDENT>val = self._object.ReadValue(<EOL>{'<STR_LIT>': dbus.UInt16(offset, variant_level=<NUM_LIT:1>)},<EOL>dbus_interface='<STR_LIT>')<EOL>return val<EOL><DEDENT>except dbus.exceptions.DBusException as e:<EOL><INDENT>error = _error_from_dbus_error(e)<EOL>self.service.device.descriptor_read_value_failed(self, error=error)<EOL><DEDENT>
Reads the value of this descriptor.

When successful, the value will be returned, otherwise `descriptor_read_value_failed()` of the related
device is invoked.