def get_fixed_block(self, keys=[], unbuffered=False):
        """Get the decoded "fixed block" of settings and min/max data.

        A subset of the entire block can be selected by keys."""
        if unbuffered or not self._fixed_block:
            self._fixed_block = self._read_fixed_block()
        format = self.fixed_format
        # navigate down list of keys to get to wanted data
        for key in keys:
            format = format[key]
        return _decode(self._fixed_block, format)