FE_SET_TONE — Sets/resets the generation of the continuous 22kHz tone.
|enum fe_sec_tone_mode *tone|
This ioctl is used to set the generation of the continuous 22kHz tone. This call requires read/write permissions.
Usually, satellite antenna subsystems require that the digital TV device to send a 22kHz tone in order to select between high/low band on some dual-band LNBf. It is also used to send signals to DiSEqC equipment, but this is done using the DiSEqC ioctls.
NOTE: if more than one device is connected to the same antenna, setting a tone may interfere on other devices, as they may lose the capability of selecting the band. So, it is recommended that applications would change to SEC_TONE_OFF when the device is not used.
On success 0 is returned, on error -1 and the
errno variable is set appropriately. The generic error codes are described at the Generic Error Codes chapter.