SCHSIO_FAN_RPM
sc->sc_sensor[SCHSIO_SENSOR_FAN1].value = SCHSIO_FAN_RPM(tach);
sc->sc_sensor[SCHSIO_SENSOR_FAN2].value = SCHSIO_FAN_RPM(tach);
sc->sc_sensor[SCHSIO_SENSOR_FAN3].value = SCHSIO_FAN_RPM(tach);