@staticmethod
def translate_tariff(value, dsmr_version):
    """Convert 2/1 to normal/low depending on DSMR version."""
    if dsmr_version in ('5B',):
        if value == '0001':
            value = '0002'
        elif value == '0002':
            value = '0001'
    if value == '0002':
        return 'normal'
    if value == '0001':
        return 'low'
    return None
