METER
case METER:
HPI_METER_RMS = HPI_CTL_ATTR(METER, 1),
HPI_METER_PEAK = HPI_CTL_ATTR(METER, 2),
HPI_METER_RMS_BALLISTICS = HPI_CTL_ATTR(METER, 3),
HPI_METER_PEAK_BALLISTICS = HPI_CTL_ATTR(METER, 4),
HPI_METER_NUM_CHANNELS = HPI_CTL_ATTR(METER, 5),