The fan control modes of the fan frame.
Options:
1.manual(1) -indicates that the fan is always on, and the fan speed can be manually adjusted
2.emuAuto(2) -indicates that the fan is in the automatic mode, and can be automatically
controlled depending on the temperature of the fan
3.fixed(3) -indicates that the fan is in the fixed mode, and adjusting its speed is not allowed
4.mainboardAuto(4) -indicates that the fan is in the automatic mode, and can be automatically
controlled depending on the temperature of the boards in the frame